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nfcorpus-qrel-MED-2753 | Generate text that best answers this question: DHA | Secondary prevention of CHD in UK men: the Diet and Reinfarction Trial and its sequel.
The Diet and Reinfarction Trial (DART) involved 2033 men (mean age 56.5 years) recovering from myocardial infarction. They were randomly allocated to receive advice or to receive no advice on each of three dietary factors: an increase in fatty fish intake; a reduction in fat intake with an increase in polyunsaturated fat:saturated fat; an increased intake of cereal fibre. Compliance was satisfactory with the fish and fibre advice, but less so with the fat advice. The men given fish advice had 29% lower 2-year all-cause mortality; the other forms of advice did not have any significant effects. The Diet and Angina Randomized Trial (DART-2) involved 3114 men (mean age 61.1 years) with stable angina, who were followed up for 3-9 years. Advice to eat oily fish or take fish oil did not affect all-cause mortality, but it was associated with a significant increase in sudden cardiac death (P=0.018), and this effect was largely confined to the subgroup given fish oil capsules. Advice to eat more fruit and vegetables had no effect, probably because of poor compliance. The outcome of DART-2 appears to conflict with that of DART and some other studies; various possible explanations are considered. Nutritional interventions are not equally acceptable and should be tailored to the individuals for whom they are intended. Various distinct groups have a raised risk of CHD, and it cannot be assumed that the same nutritional interventions are appropriate to them all. Nutritional supplements do not necessarily have the same effects as the foods from which they are derived. |
nfcorpus-qrel-MED-2756 | Generate text that best answers this question: DHA | Fish consumption, omega-3 fatty acids, and environmental contaminants in relation to low-grade inflammation and early atherosclerosis.
BACKGROUND: Fish consumption and omega-3 polyunsaturated fatty acid (PUFA) intake are shown to protect from cardiovascular diseases (CVD). However, most fish contain environmental contaminants such as dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and methylmercury (MeHg) that may have adverse effects on cardiovascular health. OBJECTIVE: Our aim was to elucidate the associations of fish consumption, omega-3 PUFAs, environmental contaminants with low-grade inflammation, early atherosclerosis, and traditional CVD risk factors. METHODS: The Health 2000 survey participants (n=1173) represented the general Finnish population and the Fishermen study participants (n=255) represented a population with high fish consumption and high exposure to environmental contaminants. Model-adjusted geometric means and tests for linear trend were calculated for CVD risk factors by tertiles of fish consumption and serum omega-3 PUFAs, and additionally in the Fishermen study only, by tertiles of serum PCDD/F+PCB, and blood MeHg. RESULTS: Serum triglyceride decreased across omega-3 PUFA tertiles in both sexes and studies. Insulin resistance, C-reactive protein, tumour necrosis factor α, and interleukin 6 decreased across omega-3 PUFA tertiles among the Health 2000 survey participants. Among the Fishermen study men, insulin resistance and arterial stiffness indicated by β-stiffness index tended to increase and the RR estimate for carotid artery plaque tended to decrease across tertiles of PCDD/F+PCB and MeHg. CONCLUSION: Previously established hypotriglyceridemic and anti-inflammatory effects of omega-3 PUFAs were seen also in this study. The hypothesised favourable effect on insulin sensitivity and arterial elasticity was suggested to be counteracted by high exposure to environmental contaminants but the effect on plaque prevalence appeared not to be harmful. Copyright © 2012 Elsevier Inc. All rights reserved. |
nfcorpus-qrel-MED-3023 | Generate text that best answers this question: DHA | Relationship between the prenatal exposure to low-level of mercury and the size of a newborn's cerebellum.
Exposure to methylmercury at any stage of central nervous system development could induce alterations and result in severe congenital abnormalities. Total mercury level in maternal hair during pregnancy correlates well with blood levels of methylmercury and with total mercury levels in fetal brain. A prospective study has been conducted and a total of 137 childbearing women living at the coastal region with term, normal pregnancies were included and their newborns evaluated by ultrasonography. Mothers and their newborns are divided in two groups according to their hair mercury levels; examined group with high body levels of mercury (≥ 1 μg/g) and control group with low body levels of mercury (<1 μg/g). Neurosonographic examination was conducted to all newborns. Two dimensions of cerebellum in the sagital-medial plane have been measured: maximum height and width starting from the roof of the fourth chamber. Majority of mothers had hair mercury levels lower than 1 μg/g (N = 107). Mean value was 0.88 μg/g (SD 1.24), ranging from 0.02 to 8.71 μg/g. There was no significant difference between the two groups when it comes to the width of cerebellum (Mann-Whitney test: Z = 1471; p = 0.141). However, comparison related to the length of cerebellum shows statistically significant smaller cerebellum in newborns whose mother had hair mercury levels higher than 1 μg/g (Mann-Whitney test: Z = 2329; p = 0.019). Our results lead to a conclusion that prenatal exposure to, what we consider to be, low-levels of methylmercury does influence fetal brain development detected as decreased size of newborn's cerebellum. From a clinical point of view, a question related to the influence of prenatal low-level methylmercury exposure on fetal neurodevelopment remains open. Our further objectives are to direct the research towards performing detailed neuropshychological tests on children at the age of 18 months. Such tests could indicate the presence of subtle neurological or neuropsychological deficits. Copyright © 2010 Elsevier Ltd. All rights reserved. |
nfcorpus-qrel-MED-2904 | Generate text that best answers this question: DHA | Dose–Response Relationship of Prenatal Mercury Exposure and IQ: An Integrative Analysis of Epidemiologic Data
Background Prenatal exposure to mercury has been associated with adverse childhood neurologic outcomes in epidemiologic studies. Dose–response information for this relationship is useful for estimating benefits of reduced mercury exposure. Objectives We estimated a dose–response relationship between maternal mercury body burden and subsequent childhood decrements in intelligence quotient (IQ), using a Bayesian hierarchical model to integrate data from three epidemiologic studies. Methods Inputs to the model consist of dose–response coefficients from studies conducted in the Faroe Islands, New Zealand, and the Seychelles Islands. IQ coefficients were available from previous work for the latter two studies, and a coefficient for the Faroe Islands study was estimated from three IQ subtests. Other tests of cognition/achievement were included in the hierarchical model to obtain more accurate estimates of study-to-study and end point–to–end point variability. Results We find a central estimate of −0.18 IQ points (95% confidence interval, −0.378 to −0.009) for each parts per million increase of maternal hair mercury, similar to the estimates for both the Faroe Islands and Seychelles studies, and lower in magnitude than the estimate for the New Zealand study. Sensitivity analyses produce similar results, with the IQ coefficient central estimate ranging from −0.13 to −0.25. Conclusions IQ is a useful end point for estimating neurodevelopmental effects, but may not fully represent cognitive deficits associated with mercury exposure, and does not represent deficits related to attention and motor skills. Nevertheless, the integrated IQ coefficient provides a more robust description of the dose–response relationship for prenatal mercury exposure and cognitive functioning than results of any single study. |
nfcorpus-qrel-MED-2905 | Generate text that best answers this question: DHA | Associations of maternal long chain polyunsaturated fatty acids, methyl mercury, and infant development in the Seychelles Child Development Nutrition Study
Fish consumption during gestation can provide the fetus with long chain polyunsaturated fatty acids (LCPUFA) and other nutrients essential for growth and development of the brain. However, fish consumption also exposes the fetus to the neurotoxicant, methyl mercury (MeHg). We studied the association between these fetal exposures and early child development in the Seychelles Child Development Nutrition Study (SCDNS). Specifically, we examined a priori models of Ω-3 and Ω-6 LCPUFA measures in maternal serum to test the hypothesis that these LCPUFA families before or after adjusting for prenatal MeHg exposure would reveal associations with child development assessed by the BSID-II at ages 9 and 30 months. There were 229 children with complete outcome and covariate data available for analysis. At 9 months, the PDI was positively associated with total Ω-3 LCPUFA and negatively associated with the ratio of Ω-6/Ω-3 LCPUFA. These associations were stronger in models adjusted for prenatal MeHg exposure. Secondary models suggested that the MeHg effect at 9 months varied by the ratio of Ω-6/Ω-3 LCPUFA. There were no significant associations between LCPUFA measures and the PDI at 30 months. There were significant adverse associations, however, between prenatal MeHg and the 30 month PDI when the LCPUFA measures were included in the regression analysis. The BSID-II Mental Developmental Index (MDI) was not associated with any exposure variable. These data support the potential importance to child development of prenatal availability of Ω-3 LCPUFA present in fish and of LCPUFA in the overall diet. Furthermore, they indicate that the beneficial effects of LCPUFA can obscure the determination of adverse effects of prenatal MeHg exposure in longitudinal observational studies. |
nfcorpus-qrel-MED-2907 | Generate text that best answers this question: DHA | Which Fish Should I Eat? Perspectives Influencing Fish Consumption Choices
Background: Diverse perspectives have influenced fish consumption choices. Objectives: We summarized the issue of fish consumption choice from toxicological, nutritional, ecological, and economic points of view; identified areas of overlap and disagreement among these viewpoints; and reviewed effects of previous fish consumption advisories. Methods: We reviewed published scientific literature, public health guidelines, and advisories related to fish consumption, focusing on advisories targeted at U.S. populations. However, our conclusions apply to groups having similar fish consumption patterns. Discussion: There are many possible combinations of matters related to fish consumption, but few, if any, fish consumption patterns optimize all domains. Fish provides a rich source of protein and other nutrients, but because of contamination by methylmercury and other toxicants, higher fish intake often leads to greater toxicant exposure. Furthermore, stocks of wild fish are not adequate to meet the nutrient demands of the growing world population, and fish consumption choices also have a broad economic impact on the fishing industry. Most guidance does not account for ecological and economic impacts of different fish consumption choices. Conclusion: Despite the relative lack of information integrating the health, ecological, and economic impacts of different fish choices, clear and simple guidance is necessary to effect desired changes. Thus, more comprehensive advice can be developed to describe the multiple impacts of fish consumption. In addition, policy and fishery management inter-ventions will be necessary to ensure long-term availability of fish as an important source of human nutrition. |
nfcorpus-qrel-MED-3024 | Generate text that best answers this question: DHA | Dietary lipids modulate methylmercury toxicity in Atlantic salmon.
This experiment aimed to study the molecular toxicity of methylmercury (MeHg) in liver, brain and white muscle of Atlantic salmon fed a diet based on fish oil (FO, high dietary n-3/n-6 ratio) compared to an alternative diet mainly based on vegetable oil (VO, low dietary n-3/n-6 ratio). Juvenile salmon were fed decontaminated diets or the FO and VO diets enriched with 5 mg Hg/kg (added as MeHg) for three months. The dietary lipid composition affected the fatty acid composition in the tissues, especially in liver and white muscle. After 84 days of exposure, the liver accumulated three times as much MeHg as the brain and white muscle. Vitamin C content and heme oxygenase, tubulin alpha (TUBA) and Cpt1 transcriptional levels all showed significant effects of MeHg exposure in the liver. TBARS, α-tocopherol, γ-tocopherol, and the transcriptional levels of thioredoxin, heme oxygenase, TUBA, PPARB1, D5D and D6D showed an effect of dietary lipid composition in liver tissue. Effects of dietary lipids were observed in brain tissue for MT-A, HIF1, Bcl-X and TUBA. Interaction effects between MeHg exposure and dietary lipid composition were observed in all tissues. Our data suggest that dietary fats have modulating effects on MeHg toxicity in Atlantic salmon. Copyright © 2011 Elsevier Ltd. All rights reserved. |
nfcorpus-qrel-MED-3025 | Generate text that best answers this question: DHA | Abnormal neuronal migration, deranged cerebral cortical organization, and diffuse white matter astrocytosis of human fetal brain: a major effect of...
Detailed clinical and neuropathological studies have been made in two fullterm newborn human infants who were exposed to methylmercury in utero as a result of maternal ingestion of methylmercury-contaminated bread in early phases of pregnancy. High levels of mercury were detected in various regions of the brain at autopsy. Study of the brains revealed a disturbance in the development in both cases, consisting essentially of an incomplete or abnormal migration of neurons to the cerebellar and cerebral cortices, and deranged cortical organization of the cerebrum. There were numerous heterotopic neurons, both isolated and in groups, in the white matter of cerebrum and cerebellum and the laminar cortical pattern of the laminar cortical pattern of the cerebrum was disturbed in many regions as was shown by the irregular groupings and the deranged alignment of cortical. Prominent in the white matter of the cerebrum and the cerebellum was diffuse gemistocytic astrocytosis accompanied by an accumulation of mercury grains in their cytoplasm. These findings indicate a high degree of vulnerability of human fetal brain to maternal intoxication by methylmercury. A major effect appears to be related to faulty development and not to destructive focal neuronal damage as has been observed in mercury intoxicaiton in adults and children exposed postnatally. |
nfcorpus-qrel-MED-2910 | Generate text that best answers this question: DHA | Sensitivity of Continuous Performance Test (CPT) at Age 14 Years to Developmental Methylmercury Exposure
Hit Reaction Time latencies (HRT) in the Continuous Performance Test (CPT) measure the speed of visual information processing. The latencies may involve different neuropsychological functions depending on the time from test initiation, i.e., first orientation, learning and habituation, then cognitive processing and focused attention, and finally sustained attention as the dominant demand. Prenatal methylmercury exposure is associated with increased reaction time (RT) latencies. We therefore examined the association of methylmercury exposure with the average HRT at age 14 years at three different time intervals after test initiation. A total of 878 adolescents (87% of birth cohort members) completed the CPT. The RT latencies were recorded for 10 minutes, with visual targets presented at 1000 ms intervals. After confounder adjustment, regression coefficients showed that CPT-RT outcomes differed in their associations with exposure biomarkers of prenatal methylmercury exposure: During the first two minutes, the average HRT was weakly associated with methylmercury (beta (SE) for a ten-fold increase in exposure, (3.41 (2.06)), was strongly for the 3-to-6 minute interval (6.10 (2.18)), and the strongest during 7–10 minutes after test initiation (7.64 (2.39)). This pattern was unchanged when simple reaction time and finger tapping speed were included in the models as covariates. Postnatal methylmercury exposures did not affect the outcomes. Thus, these findings suggest that sustained attention as a neuropsychological domain is particularly vulnerable to developmental methylmercury exposure, indicating probable underlying dysfunction of the frontal lobes. When using CPT data as a possible measure of neurotoxicity, test results should therefore be analyzed in regard to time from test initiation and not as overall average reaction times. |
nfcorpus-qrel-MED-3027 | Generate text that best answers this question: DHA | Marine Food Pollutants as a Risk Factor for Hypoinsulinemia and Type 2 Diabetes
Background Some persistent environmental chemicals are suspected of causing an increased risk of type 2 diabetes mellitus, a disease particularly common after age 70. This concern was examined in a cross-sectional study of elderly subjects in a population with elevated contaminant exposures from seafood species high in the food chain. Methods Clinical examinations of 713 Faroese residents aged 70-74 years (64% of eligible population) included fasting plasma concentrations of glucose and insulin, and glycosylated hemoglobin. Lifetime exposure to persistent environmental chemicals from pilot whale and other traditional food was estimated from a dietary questionnaire and by analysis of blood samples for polychlorinated biphenyls (PCBs) and related food contaminants. Results Septuagenarians with type 2 diabetes or impaired fasting glycemia tended to have higher PCB concentrations and higher past intake of traditional foods, especially during childhood and adolescence. In non-diabetic subjects, the fasting insulin concentration decreased by 7% (95% CI= −12% to −2%) for each doubling of the PCB concentration after adjustment for sex and body mass index at age 20. Conversely, the fasting glucose concentration increased by 6% (−1% to 13%) for each doubling in PCB. Similar associations were seen in subjects without impaired fasting glycemia, while further adjustment for current body mass index and lipid metabolism parameters attenuated some of the associations. Conclusions Impaired insulin secretion appears to constitute an important part of the type 2 diabetes pathogenesis associated with exposure to persistent lipophilic food contaminants. |
nfcorpus-qrel-MED-3013 | Generate text that best answers this question: DHA | Reducing the staggering costs of environmental disease in children, estimated at $76.6 billion in 2008.
A 2002 analysis documented $54.9 billion in annual costs of environmentally mediated diseases in US children. However, few important changes in federal policy have been implemented to prevent exposures to toxic chemicals. We therefore updated and expanded the previous analysis and found that the costs of lead poisoning, prenatal methylmercury exposure, childhood cancer, asthma, intellectual disability, autism, and attention deficit hyperactivity disorder were $76.6 billion in 2008. To prevent further increases in these costs, efforts are needed to institute premarket testing of new chemicals; conduct toxicity testing on chemicals already in use; reduce lead-based paint hazards; and curb mercury emissions from coal-fired power plants. |
nfcorpus-qrel-MED-3030 | Generate text that best answers this question: DHA | Do national advisories serve local consumers: an assessment of mercury in economically important North Carolina fish.
Consumption of marine fish provides both benefits (lean protein, omega-3 fatty acids and essential nutrients) and risks (main source of mercury (Hg) exposure for humans). Mercury is a potent neurotoxin and the source of more fish advisories nationwide than any other toxicant. Despite the widespread nature of Hg, it is unknown whether local Hg contamination reflects national and regional levels often used as bases to inform consumers of potential fish consumption risk. Thus, the objectives of our study were to examine Hg levels of six commonly consumed marine species harvested locally off the North Carolina coast and to compare our results to published regional (Monterey Bay Aquarium's Seafood Watch List) and national (Environmental Protection Agency, EPA, and Food and Drug Administration, FDA) Hg averages, action levels, and guidelines. We found significant differences in Hg concentrations among collected species, and we identified correlations between Hg concentration and fish length and trophic levels. Collected mahi mahi and triggerfish were below the EPA fish tissue action level (0.3ppm). Wahoo and grouper exceeded the EPA action level but were below the FDA action level (1.0ppm). King mackerel had the highest Hg concentration among targeted species, exceeding both EPA and FDA action levels. Further, our local results were not always consistent with calculated averages from EPA and FDA databases for the same species, and although many of our findings were consistent with Monterey Bay Aquarium's Seafood Watch List (southeast region), recommendations based on Hg levels would conflict with recommendations they provide based on sustainability. We find regional and national averages are not always reflective of local Hg contamination and suggest local data may be needed to accurately assess consumer risk. |
nfcorpus-qrel-MED-2917 | Generate text that best answers this question: DHA | Nutrients and contaminants in human milk from mothers on macrobiotic and omnivorous diets.
The effect of alternative dietary habits and prolonged lactation on the nutrient and contaminant concentrations in human milk was studied. The study sample consisted of mothers on macrobiotic diets, containing little or no diary products and meat, at 2-3 months postpartum (n = 9) and 9-13 months postpartum (n = 12), and mothers on omnivorous diets at 2-3 months postpartum (n = 10). Protein and zinc concentrations in breast-milk from macrobiotic mothers decreased with stage of lactation. After adjustment for stage of lactation, milk from macrobiotic mothers contained less calcium, magnesium and saturated fatty acids C15:0-C20:0, and more polyunsaturated fatty acids. Observed tendencies for lower protein and fat and higher lactose concentrations in the macrobiotic group were not statistically significant. Concentrations of vitamin B12, HCB and polychlorinated biphenyls (PCB 118, PCB 138, PCB 153 and PCB 180) were lower in the macrobiotic group. After adjustment for confounding variables, meat and fish consumption, but not dairy products, contributed to vitamin B12 concentrations. Meat and diary products strongly contributed to breast-milk concentrations of dieldrin and PCBs, fish to PCB 118, and smoking to DDT and dieldrin. Our findings suggest that breast-milk contamination could be reduced by abstinence from smoking and a moderate intake of animal products. However, risk of nutritional deficiencies rules out complete avoidance of meat, fish or diary products. Quantitative research on the effects of a reduced consumption of animal products, as well as smoking, on breast-milk contamination is warranted. |
nfcorpus-qrel-MED-3035 | Generate text that best answers this question: DHA | Functional MRI approach to developmental methylmercury and polychlorinated biphenyl neurotoxicity
Prenatal and early childhood exposure to methylmercury (MeHg) or polychlorinated biphenyls (PCBs) are associated with deficits in cognitive, sensory, motor and other functions measured by neurobehavioral tests. The main objective of this pilot study was to determine whether functional magnetic resonance imaging (fMRI) is effective for visualization of brain function alterations related to neurobehavior in subjects with high prenatal exposure to the two neurotoxicants, MeHg and PCBs. Twelve adolescents (all boys) from a Faroese birth cohort assembled in 1986–1987 were recruited based on their prenatal exposures to MeHg and PCB. All underwent fMRI scanning during behavioral tasks at age 15 years. Subjects with high mixed exposure to MeHg and PCBs were compared to those with low mixed exposure on fMRI photic stimulation and a motor task. Boys with low mixed exposures showed patterns of fMRI activation during visual and motor tasks that are typical of normal control subjects. However, those with high exposures showed activation in more areas of the brain and different and wider patterns of activation than the low mixed exposure group. The brain activation patterns observed in association with increased exposures to MeHg and PCBs are meaningful in regard to the known neurotoxicity of these substances. This methodology therefore has potential utility in visualizing structural neural system determinants of exposure-induced neurobehavioral dysfunction. |
nfcorpus-qrel-MED-2921 | Generate text that best answers this question: DHA | Evidence on the Human Health Effects of Low-Level Methylmercury Exposure
Background: Methylmercury (MeHg) is a known neuro-toxicant. Emerging evidence indicates it may have adverse effects on the neuro-logic and other body systems at common low levels of exposure. Impacts of MeHg exposure could vary by individual susceptibility or be confounded by bene-ficial nutrients in fish containing MeHg. Despite its global relevance, synthesis of the available literature on low-level MeHg exposure has been limited. Objectives: We undertook a synthesis of the current knowledge on the human health effects of low-level MeHg exposure to provide a basis for future research efforts, risk assessment, and exposure remediation policies worldwide. Data sources and extraction: We reviewed the published literature for original human epidemio-logic research articles that reported a direct biomarker of mercury exposure. To focus on high-quality studies and those specifically on low mercury exposure, we excluded case series, as well as studies of populations with unusually high fish consumption (e.g., the Seychelles), marine mammal consumption (e.g., the Faroe Islands, circumpolar, and other indigenous populations), or consumption of highly contaminated fish (e.g., gold-mining regions in the Amazon). Data synthesis: Recent evidence raises the possibility of effects of low-level MeHg exposure on fetal growth among susceptible subgroups and on infant growth in the first 2 years of life. Low-level effects of MeHg on neuro-logic outcomes may differ by age, sex, and timing of exposure. No clear pattern has been observed for cardio-vascular disease (CVD) risk across populations or for specific CVD end points. For the few studies evaluating immunologic effects associated with MeHg, results have been inconsistent. Conclusions: Studies targeted at identifying potential mechanisms of low-level MeHg effects and characterizing individual susceptibility, sexual dimorphism, and non-linearity in dose response would help guide future prevention, policy, and regulatory efforts surrounding MeHg exposure. |
nfcorpus-qrel-MED-3019 | Generate text that best answers this question: DHA | Evidence on the Human Health Effects of Low-Level Methylmercury Exposure
Background: Methylmercury (MeHg) is a known neuro-toxicant. Emerging evidence indicates it may have adverse effects on the neuro-logic and other body systems at common low levels of exposure. Impacts of MeHg exposure could vary by individual susceptibility or be confounded by bene-ficial nutrients in fish containing MeHg. Despite its global relevance, synthesis of the available literature on low-level MeHg exposure has been limited. Objectives: We undertook a synthesis of the current knowledge on the human health effects of low-level MeHg exposure to provide a basis for future research efforts, risk assessment, and exposure remediation policies worldwide. Data sources and extraction: We reviewed the published literature for original human epidemio-logic research articles that reported a direct biomarker of mercury exposure. To focus on high-quality studies and those specifically on low mercury exposure, we excluded case series, as well as studies of populations with unusually high fish consumption (e.g., the Seychelles), marine mammal consumption (e.g., the Faroe Islands, circumpolar, and other indigenous populations), or consumption of highly contaminated fish (e.g., gold-mining regions in the Amazon). Data synthesis: Recent evidence raises the possibility of effects of low-level MeHg exposure on fetal growth among susceptible subgroups and on infant growth in the first 2 years of life. Low-level effects of MeHg on neuro-logic outcomes may differ by age, sex, and timing of exposure. No clear pattern has been observed for cardio-vascular disease (CVD) risk across populations or for specific CVD end points. For the few studies evaluating immunologic effects associated with MeHg, results have been inconsistent. Conclusions: Studies targeted at identifying potential mechanisms of low-level MeHg effects and characterizing individual susceptibility, sexual dimorphism, and non-linearity in dose response would help guide future prevention, policy, and regulatory efforts surrounding MeHg exposure. |
nfcorpus-qrel-MED-3022 | Generate text that best answers this question: DHA | The many faces of methylmercury poisoning.
Methylmercury (MM) is a very potent neurotoxic agent. Its role in polluting the environment is well documented. A vast amount of study over the past several decades has finally provided insight into many aspects of its effect. Exposure to MM may be through ingestion of poisoned fish or inadvertent misuse of grain treated with the poison as a fungicide. Major epidemics have occurred in Japan (Fetal Minamata disease), Iraq, Pakistan, Guatemala, and Ghana. Sporadic incidences have occurred in the United States and Canada. There is no effective antidote to counteract the effect of MM on the central nervous system, although the information documented should provide hope for more effective therapy in acute cases. |
nfcorpus-qrel-MED-3026 | Generate text that best answers this question: DHA | Dose–Response Relationship of Prenatal Mercury Exposure and IQ: An Integrative Analysis of Epidemiologic Data
Background Prenatal exposure to mercury has been associated with adverse childhood neurologic outcomes in epidemiologic studies. Dose–response information for this relationship is useful for estimating benefits of reduced mercury exposure. Objectives We estimated a dose–response relationship between maternal mercury body burden and subsequent childhood decrements in intelligence quotient (IQ), using a Bayesian hierarchical model to integrate data from three epidemiologic studies. Methods Inputs to the model consist of dose–response coefficients from studies conducted in the Faroe Islands, New Zealand, and the Seychelles Islands. IQ coefficients were available from previous work for the latter two studies, and a coefficient for the Faroe Islands study was estimated from three IQ subtests. Other tests of cognition/achievement were included in the hierarchical model to obtain more accurate estimates of study-to-study and end point–to–end point variability. Results We find a central estimate of −0.18 IQ points (95% confidence interval, −0.378 to −0.009) for each parts per million increase of maternal hair mercury, similar to the estimates for both the Faroe Islands and Seychelles studies, and lower in magnitude than the estimate for the New Zealand study. Sensitivity analyses produce similar results, with the IQ coefficient central estimate ranging from −0.13 to −0.25. Conclusions IQ is a useful end point for estimating neurodevelopmental effects, but may not fully represent cognitive deficits associated with mercury exposure, and does not represent deficits related to attention and motor skills. Nevertheless, the integrated IQ coefficient provides a more robust description of the dose–response relationship for prenatal mercury exposure and cognitive functioning than results of any single study. |
nfcorpus-qrel-MED-3029 | Generate text that best answers this question: DHA | Which Fish Should I Eat? Perspectives Influencing Fish Consumption Choices
Background: Diverse perspectives have influenced fish consumption choices. Objectives: We summarized the issue of fish consumption choice from toxicological, nutritional, ecological, and economic points of view; identified areas of overlap and disagreement among these viewpoints; and reviewed effects of previous fish consumption advisories. Methods: We reviewed published scientific literature, public health guidelines, and advisories related to fish consumption, focusing on advisories targeted at U.S. populations. However, our conclusions apply to groups having similar fish consumption patterns. Discussion: There are many possible combinations of matters related to fish consumption, but few, if any, fish consumption patterns optimize all domains. Fish provides a rich source of protein and other nutrients, but because of contamination by methylmercury and other toxicants, higher fish intake often leads to greater toxicant exposure. Furthermore, stocks of wild fish are not adequate to meet the nutrient demands of the growing world population, and fish consumption choices also have a broad economic impact on the fishing industry. Most guidance does not account for ecological and economic impacts of different fish consumption choices. Conclusion: Despite the relative lack of information integrating the health, ecological, and economic impacts of different fish choices, clear and simple guidance is necessary to effect desired changes. Thus, more comprehensive advice can be developed to describe the multiple impacts of fish consumption. In addition, policy and fishery management inter-ventions will be necessary to ensure long-term availability of fish as an important source of human nutrition. |
nfcorpus-qrel-MED-3032 | Generate text that best answers this question: DHA | Associations of maternal long chain polyunsaturated fatty acids, methyl mercury, and infant development in the Seychelles Child Development Nutrition Study
Fish consumption during gestation can provide the fetus with long chain polyunsaturated fatty acids (LCPUFA) and other nutrients essential for growth and development of the brain. However, fish consumption also exposes the fetus to the neurotoxicant, methyl mercury (MeHg). We studied the association between these fetal exposures and early child development in the Seychelles Child Development Nutrition Study (SCDNS). Specifically, we examined a priori models of Ω-3 and Ω-6 LCPUFA measures in maternal serum to test the hypothesis that these LCPUFA families before or after adjusting for prenatal MeHg exposure would reveal associations with child development assessed by the BSID-II at ages 9 and 30 months. There were 229 children with complete outcome and covariate data available for analysis. At 9 months, the PDI was positively associated with total Ω-3 LCPUFA and negatively associated with the ratio of Ω-6/Ω-3 LCPUFA. These associations were stronger in models adjusted for prenatal MeHg exposure. Secondary models suggested that the MeHg effect at 9 months varied by the ratio of Ω-6/Ω-3 LCPUFA. There were no significant associations between LCPUFA measures and the PDI at 30 months. There were significant adverse associations, however, between prenatal MeHg and the 30 month PDI when the LCPUFA measures were included in the regression analysis. The BSID-II Mental Developmental Index (MDI) was not associated with any exposure variable. These data support the potential importance to child development of prenatal availability of Ω-3 LCPUFA present in fish and of LCPUFA in the overall diet. Furthermore, they indicate that the beneficial effects of LCPUFA can obscure the determination of adverse effects of prenatal MeHg exposure in longitudinal observational studies. |
nfcorpus-qrel-MED-4551 | Generate text that best answers this question: DHA | Maternal meat and fat consumption during pregnancy and suspected atopic eczema in Japanese infants aged 3-4 months: the Osaka Maternal and Child He...
Interest has increased in the possibility that maternal dietary intake during pregnancy might influence the development of allergic disorders in children. The present prospective study examined the association of maternal intake of selected foods high in fatty acids and specific types of fatty acids during pregnancy with the risk of suspected atopic eczema among Japanese infants aged 3-4 months. Subjects were 771 mother-child pairs. Information on maternal dietary intake during pregnancy was assessed with a validated self-administered diet history questionnaire. The term 'suspected atopic eczema' was used to define an outcome based on results of our questionnaire completed by mothers 3-4 months postpartum. The risk of suspected atopic eczema was 8.4% (n = 65). Higher maternal intake of meat during pregnancy was significantly associated with an increased risk of suspected atopic eczema in the offspring: the multivariate odds ratio (OR) for the highest vs. lowest quartile was 2.59 [95% confidence interval (CI): 1.15-6.17, p for trend = 0.01]. The positive association was strengthened when the definition of the outcome was confined to a definite physician's diagnosis of atopic eczema (n = 35): the multivariate OR between extreme quartiles was 3.53 (95% CI: 1.19-12.23, p for trend = 0.02). No material exposure-response relationships were observed between maternal intake of eggs, dairy products, fish, total fat, saturated fatty acids, monounsaturated fatty acids, n-3 polyunsaturated fatty acids, alpha-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, n-6 polyunsaturated fatty acids, linoleic acid, arachidonic acid and cholesterol and the ratio of n-3 to n-6 polyunsaturated fatty acid consumption and the risk of suspected atopic eczema. Higher maternal meat intake may increase the risk of infantile atopic eczema, whereas we found no evidence that maternal intake of fish and n-3 polyunsaturated fatty acids are preventive against infantile atopic eczema. (c) 2009 John Wiley & Sons A/S |
nfcorpus-qrel-MED-4936 | Generate text that best answers this question: DHA | Algal-oil capsules and cooked salmon: nutritionally equivalent sources of docosahexaenoic acid.
Food and nutrition professionals question whether supplement-sourced nutrients appear to be equivalent to those derived from natural food sources. We compared the nutritional availability of docosahexaenoic acid (DHA) from algal-oil capsules to that from assayed cooked salmon in 32 healthy men and women, ages 20 to 65 years, in a randomized, open-label, parallel-group study. In this 2-week study comparing 600 mg DHA/day from algal-oil capsules to that from assayed portions of cooked salmon, mean change from baseline in plasma phospholipids and erythrocyte DHA levels was analyzed and DHA levels were compared by Student's t tests. In post-hoc analyses to determine bioequivalence, least-squares mean ratios of percent change from baseline in plasma phospholipid and erythrocyte DHA levels were compared. DHA levels increased by approximately 80% in plasma phospholipids and by approximately 25% in erythrocytes in both groups. Changes in DHA levels in plasma phospholipids and erythrocytes were similar between groups. As measured by delivery of DHA to both plasma and erythrocytes, fish and algal-oil capsules were equivalent. Both regimens were generally well-tolerated. These results indicate that algal-oil DHA capsules and cooked salmon appear to be bioequivalent in providing DHA to plasma and red blood cells and, accordingly, that algal-oil DHA capsules represent a safe and convenient source of non-fish-derived DHA. |
nfcorpus-qrel-MED-4730 | Generate text that best answers this question: DHA | Simultaneous quantitation of multiple classes of organohalogen compounds in fish oils with direct sample introduction comprehensive two-dimensional...
We successfully optimized an analytical method using gel permeation chromatography followed by direct sample introduction comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry to quantify multiple groups of targeted persistent organic pollutants and halogenated natural products (HNPs) simultaneously in fish oil samples. This new method has a wider analytical scope than the traditional approach to use multiple methods to cover each class of compounds. Our analysis revealed that the relatively more volatile and lighter organic compounds, such as polychlorinated biphenyls (PCBs), organochlorine pesticides, and other smaller organohalogen compounds, were still present in two brands of "PCB-free" cod liver oils, albeit at much lower levels than in an untreated commercial sample. Moreover, the less volatile organic compounds, such as polybrominated diphenyl ethers and brominated HNPs, were detected at similar levels in all three cod liver oils. This suggests that the commercial molecular distillation treatment used for removal of organic/inorganic toxic contaminants is only effective for the lighter organic contaminants. |
nfcorpus-qrel-MED-4632 | Generate text that best answers this question: DHA | The effect of vegetarian diets on plasma lipid and platelet levels.
Vegetarians have an apparent diminished risk for the development of ischemic coronary heart disease. This may be secondary to dietary effects of plasma lipids and lipoproteins, but platelets, which may also play a role, have also been observed to have aberrant functions in vegetarians. We measured plasma lipid and lipoprotein levels, platelet function, platelet fatty acid levels, and platelet active prostaglandins in ten strict vegetarians (vegans), 15 lactovegetarians, and 25 age- and sex-matched omnivorous controls. The most striking observations were a highly significant rise in platelet linoleic acid concentration and a decline in platelet arachidonic acid concentration in both vegetarian subgroups as compared with omnivorous controls. Serum thromboxane and prostacyclin levels as well as results of platelet aggregation studies did not differ among the groups tested. Cholesterol levels were significantly lower in both vegetarian groups as compared with controls, but plasma high- and low-density lipoprotein levels were lower only in the vegan subgroup as compared with omnivores. If diet produces these changes in platelet fatty acid and plasma lipid levels it may contribute to the decreased risk of coronary heart disease and possibly atherosclerosis in vegetarians. |
nfcorpus-qrel-MED-4633 | Generate text that best answers this question: DHA | Vegetarian diets are associated with healthy mood states: a cross-sectional study in Seventh Day Adventist adults
Background The physical health status of vegetarians has been extensively reported, but there is limited research regarding the mental health status of vegetarians, particularly with regard to mood. Vegetarian diets exclude fish, the major dietary source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), critical regulators of brain cell structure and function. Omnivorous diets low in EPA and DHA are linked to impaired mood states in observational and experimental studies. Methods We examined associations between mood state and polyunsaturated fatty acid intake as a result of adherence to a vegetarian or omnivorous diet in a cross-sectional study of 138 healthy Seventh Day Adventist men and women residing in the Southwest. Participants completed a quantitative food frequency questionnaire, Depression Anxiety Stress Scale (DASS), and Profile of Mood States (POMS) questionnaires. Results Vegetarians (VEG:n = 60) reported significantly less negative emotion than omnivores (OMN:n = 78) as measured by both mean total DASS and POMS scores (8.32 ± 0.88 vs 17.51 ± 1.88, p = .000 and 0.10 ± 1.99 vs 15.33 ± 3.10, p = .007, respectively). VEG reported significantly lower mean intakes of EPA (p < .001), DHA (p < .001), as well as the omega-6 fatty acid, arachidonic acid (AA; p < .001), and reported higher mean intakes of shorter-chain α-linolenic acid (p < .001) and linoleic acid (p < .001) than OMN. Mean total DASS and POMS scores were positively related to mean intakes of EPA (p < 0.05), DHA (p < 0.05), and AA (p < 0.05), and inversely related to intakes of ALA (p < 0.05), and LA (p < 0.05), indicating that participants with low intakes of EPA, DHA, and AA and high intakes of ALA and LA had better mood. Conclusions The vegetarian diet profile does not appear to adversely affect mood despite low intake of long-chain omega-3 fatty acids. |
nfcorpus-qrel-MED-4634 | Generate text that best answers this question: DHA | Fatty acid profile of human saliva: a possible indicator of dietary fat intake.
OBJECTIVE: Since conventional food questionnaires are not precise in assessing the dietary fatty acids, the purpose of this study was to determine the relationship between the salivary fatty acid profile and the alimentary habits of two different groups in an attempt to develop a more reliable way to determine the lipidic intake. DESIGN: Twenty adults of both sexes, with mixed (M) or vegetarian (V) diets were studied. Data about the fat intake were obtained by means of a Food Frequency Questionnaire (FFQ) and the presence of the main salivary fatty acids was determined by gas chromatography. RESULTS: A greater salivary concentration of alpha-linolenic acid (18:3 n-3) (2.82) was found in V than in M subjects (1.65) (p = 0.001), whilst arachidonic acid (20:4 n-6) was lower in V (3.93) than in M (4.52) (p = 0.045). The same difference regarding arachidonic acid was observed in the dietary fatty acid intake, also showing a significant correlation between its dietary and salivary levels in vegetarian subjects. CONCLUSIONS: These results show that salivary arachidonic acid, relevant for their eicosanoid production related to the tumourigenesis process and cardiovascular diseases, is influenced by dietary fats. |
nfcorpus-qrel-MED-4729 | Generate text that best answers this question: DHA | Do Organohalogen Contaminants Contribute to Histopathology in Liver from East Greenland Polar Bears (Ursus maritimus)?
In East Greenland polar bears (Ursus maritimus), anthropogenic organohalogen compounds (OHCs) (e.g., polychlorinated biphenyls, dichlorodiphenyltrichloroethane, and polybrominated diphenyl ethers) contributed to renal lesions and are believed to reduce bone mineral density. Because OHCs are also hepatotoxic, we investigated liver histology of 32 subadult, 24 adult female, and 23 adult male East Greenland polar bears sampled during 1999–2002. Light microscopic changes consisted of nuclear displacement from the normal central cytoplasmic location in parenchymal cells, mononuclear cell infiltrations (mainly portally and as lipid granulomas), mild bile duct proliferation accompanied by fibrosis, and fat accumulation in hepatocytes and pluripotent Ito cells. Lipid accumulation in Ito cells and bile duct hyperplasia accompanied by portal fibrosis were correlated to age, whereas no changes were associated with either sex or season (summer vs. winter). For adult females, hepatocytic intracellular fat increased significantly with concentrations of the sum of hexachlorocyclohexanes, as was the case for lipid granulomas and hexachlorobenzene in adult males. Based on these relationships and the nature of the chronic inflammation, we suggest that these findings were caused by aging and long-term exposure to OHCs. Therefore, these changes may be used as biomarkers for OHC exposure in wildlife and humans. To our knowledge, this is the first time liver histology has been evaluated in relation to OHC concentrations in a mammalian wildlife species, and the information is important to future polar bear conservation strategies and health assessments of humans relying on OHC-contaminated food resources. |
nfcorpus-qrel-MED-4731 | Generate text that best answers this question: DHA | No effect of fish oil supplementation on serum inflammatory markers and their interrelationships: a randomized controlled trial in healthy, middle-...
BACKGROUND: A high intake of n-3 polyunsaturated fatty acids (PUFAs), mainly present in fish, may be associated with decreased inflammation. Previous intervention studies on fish PUFA and inflammatory markers in healthy individuals did not analyze a broad spectrum of inflammatory cytokines, chemokines and cell adhesion molecules, or their interrelationships. Therefore, we determined the effects of fish oil supplementation on 19 serum inflammatory markers and their interrelationships in healthy, middle-aged individuals. METHODS: Individuals (n=77) aged 50-70 years completed a randomized, double-blind placebo-controlled intervention study. Participants received 3.5 g/day fish oil (1.5 g/day total n-3 PUFA) (n=39) or placebo (high oleic sunflower oil) (n=38) for 12 weeks. Serum concentrations of 19 inflammatory markers were determined using a multiplex immunoassay before and after intervention. Changes in concentrations were analyzed using analysis of covariance and differences in patterns in inflammatory markers between the fish oil and placebo group were analyzed by principal component analysis. RESULTS: Fish oil supplementation did not significantly affect serum concentrations of cytokines, chemokines or cell adhesion molecules as compared with placebo. However, there was a trend for all inflammatory markers to increase after fish oil supplementation. PCA did not result in markedly distinctive patterns of inflammatory markers for the fish oil and placebo group. CONCLUSION: In conclusion, this 12-week randomized, double-blind placebo-controlled intervention trial did not show that 1.5 g/day n-3 PUFA significantly affected the serum inflammatory response in healthy individuals, nor did patterns of inflammatory markers. Thus, a healthy middle-aged population may not benefit from fish oil as an anti-inflammatory agent. |
nfcorpus-qrel-MED-4732 | Generate text that best answers this question: DHA | Polychlorinated Biphenyl-77 Induces Adipocyte Differentiation and Proinflammatory Adipokines and Promotes Obesity and Atherosclerosis
Background Obesity, an inflammatory condition linked to cardiovascular disease, is associated with expansion of adipose tissue. Highly prevalent coplanar polychlorinated biphenyls (PCBs) such as 3,3′,4,4′-tetrachlorobiphenyl (PCB-77) accumulate in adipose tissue because of their lipophilicity and increase with obesity. However, the effects of PCBs on adipocytes, obesity, and obesity-associated cardiovascular disease are unknown. Objectives In this study we examined in vitro and in vivo effects of PCB-77 on adipocyte differentiation, proinflammatory adipokines, adipocyte morphology, body weight, serum lipids, and atherosclerosis. Methods PCB-77 or 2,2′,4,4,5,5′-hexachlorobiphenyl (PCB-153) was incubated with 3T3-L1 adipocytes either during differentiation or in mature adipocytes. Concentration-dependent effects of PCB-77 were contrasted with those of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). For in vivo studies, we treated C57BL/6 wild-type (WT) or aryl hydrocarbon receptor (AhR)−/− mice with vehicle or PCB-77 (49 mg/kg, by intraperitoneal injection) and examined body weight gain. In separate studies, we injected ApoE−/− mice with vehicle or PCB-77 over a 6-week period and examined body weight, adipocyte size, serum lipids, and atherosclerosis. Results Low concentrations of PCB-77 or TCDD increased adipocyte differentiation, glycerol–3-phosphate dehydrogenase activity, and expression of peroxisome proliferator–activated receptor γ, whereas higher concentrations inhibited adipocyte differentiation. Effects of PCB-77 were abolished by the AhR antagonist α-naphthoflavone. PCB-77 promoted the expression and release of various proinflammatory cytokines from 3T3-L1 adipocytes. Administration of PCB-77 increased body weight gain in WT but not AhR−/− mice. ApoE−/− mice injected with PCB-77 exhibited greater body weight, adipocyte hypertrophy, serum dyslipidemia, and augmented atherosclerosis. Conclusions Our findings suggest that PCB-77 may contribute to the development of obesity and obesity-associated atherosclerosis. |
nfcorpus-qrel-MED-4933 | Generate text that best answers this question: DHA | Polybrominated diphenyl ethers (PBDEs) in farmed and wild salmon marketed in the Northeastern United States.
Recently, we reported on the analysis of polychlorinated biphenyls (PCBs) and chlorinated pesticides in farmed Atlantic salmon (Salmo salar) from Maine, eastern Canada, and Norway, and wild Alaskan Chinook salmon (Oncorhynchus tshawytscha). In this paper, we extend the analysis to polybrominated diphenyl ethers (PBDEs) in these samples. Total PBDE concentrations in the farmed salmon (0.4-1.4ng/g, wet weight, ww) were not significantly different from those in the wild Alaskan Chinook samples (0.4-1.2ng/g, ww), nor were significant differences found among regions. However, significant intra-regional variations in concentrations of total PBDEs and tetra-BDE 47 were observed in the salmon from the Canadian farms (p<0.01). Congener profiles were dominated by BDE-47, followed by the penta-BDEs 99 and 100. PBDE concentrations in the Canadian samples were lower than those reported two years earlier. Removal of skin resulted in no overall reduction in PBDE concentrations in our farmed salmon, and in some cases, PBDE concentrations were higher in skin-off samples. PBDEs were correlated with lipids only in the skinned samples, suggesting that there is greater accumulation and retention of PBDEs in muscle lipids than in skin-associated fat. In skin-on samples, modest correlations were observed between concentrations of PBDEs and PCBs (R(2)=0.47) and mono-ortho PCBs (R(2)=0.50), whereas PBDEs were not correlated with non-ortho PCBs. |
nfcorpus-qrel-MED-4934 | Generate text that best answers this question: DHA | Atmospherically Deposited PBDEs, Pesticides, PCBs, and PAHs in Western US National Park Fish: Concentrations and Consumption Guidelines
Concentrations of polybrominated diphenyl ethers (PBDEs), pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons were measured in 136 fish from 14 remote lakes in 8 western US National Parks/Preserves between 2003 and 2005 and compared to human and wildlife contaminant health thresholds. A sensitive (median detection limit −18 pg/g wet weight), efficient (61% recovery at 8 ng/g), reproducible (4.1 %RSD), and accurate (7 % deviation from SRM) analytical method was developed and validated for these analyses. Concentrations of PCBs, hexachlorobenzene, hexachlorocyclohexanes, DDTs and chlordanes in western US fish were comparable to or lower than mountain fish recently collected from Europe, Canada, and Asia. Dieldrin and PBDE concentrations were higher than recent measurements in mountain fish and Pacific Ocean salmon. Concentrations of most contaminants in western US fish were 1–6 orders of magnitude below calculated recreational fishing contaminant health thresholds. However, contaminant concentrations exceeded subsistence fishing cancer screening values in 8 of 14 lakes. Average contaminant concentrations in fish exceeded wildlife contaminant health thresholds for piscivorous mammals in 5 lakes, and piscivorous birds in all 14 lakes. These results indicate that atmospherically deposited organic contaminants can accumulate in high elevation fish, reaching concentrations relevant to human and wildlife health. |
nfcorpus-qrel-MED-4935 | Generate text that best answers this question: DHA | Polychlorinated naphthalenes in human adipose tissue from New York, USA.
Polychlorinated naphthalenes (PCNs) are persistent, bioaccumulative, and toxic contaminants. Prior to this study, the occurrence of PCNs in human adipose tissues from the USA has not been analyzed. Here, we have measured concentrations of PCNs in human adipose tissue samples collected in New York City during 2003-2005. Concentrations of PCNs were in the range of 61-2500pg/g lipid wt. in males and 21-910pg/g lipid wt. in females. PCN congeners 52/60 (1,2,3,5,7/1,2,4,6,7) and 66/67 (1,2,3,4,6,7/1,2,3,5,6,7) were predominant, collectively accounting for 66% of the total PCN concentrations. Concentrations of PCNs in human adipose tissues were 2-3 orders of magnitude lower than the previously reported concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Concentrations of PCNs were not correlated with PCB concentrations. The contribution of PCNs to dioxin-like toxic equivalents (TEQs) in human adipose tissues was estimated to be <1% of the polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F)-TEQs. |
nfcorpus-qrel-MED-4937 | Generate text that best answers this question: DHA | Levels of polybrominated diphenyl ethers (PBDEs) and organochlorine pollutants in two species of Antarctic fish (Chionodraco hamatus and Trematomus...
In the late 1960s the first scientific studies on contamination in Antarctica demonstrated the presence of pollutants in Antarctic ecosystems. Many Persistent Organic Pollutants (POPs) are transported globally from the areas in which they are produced and released into the environment in remote areas, including Antarctica. Here we report results obtained concerning the accumulation of polybrominated diphenyl ethers (PBDEs), mono- and non-ortho-polychlorobiphenyls (PCBs), polychlorodibenzodioxins (PCDDs) and polychlorodibenzofurans (PCDFs) in the tissues of two species of Antarctic fish (Chionodraco hamatus and Trematomus bernacchii). The 2,3,7,8-TCDD toxic equivalents (TEQs) were also calculated to evaluate the potential risk of these compounds for the two species. In general, POP levels were higher in the tissues of T. bernacchii than in C. hamatus and the highest concentrations were found in the liver of both species. The PBDE levels varied from 160.5 pg g(-1) wet wt in C. hamatus muscle to 789.9 pg g(-1) wet wt in T. bernacchii liver and were lower than the levels of PCBs. PCBs were the main organochlorine compounds detected and their concentrations ranged from 0.3 ng g(-1) wet wt in C. hamatus muscle to 15.1 ng g(-1) wet wt in T. bernacchii liver. TEQ concentrations resulted higher in C. hamatus than in T. bernacchii and were due mainly to PCDDs. The presence of PBDEs and organochlorine pollutants in the tissues of Antarctic organisms confirms their global transport and distribution. |
nfcorpus-qrel-MED-4943 | Generate text that best answers this question: DHA | Persistent organic pollutants in fish oil supplements on the Canadian market: polychlorinated biphenyls and organochlorine insecticides.
Fish and seal oil dietary supplements, marketed to be rich in omega-3 fatty acids, are frequently consumed by Canadians. Samples of these supplements (n = 30) were collected in Vancouver, Canada, between 2005 and 2007. All oil supplements were analyzed for polychlorinated biphenyls (PCBs) and organochlorine insecticides (OCs) and each sample was found to contain detectable residues. The highest SigmaPCB and SigmaDDT (1,1,1-trichloro-di-(4-chlorophenyl)ethane) concentrations (10400 ng/g and 3310 ng/g, respectively) were found in a shark oil sample while lowest levels were found in supplements prepared using mixed fish oils (anchovy, mackerel, and sardine) (0.711 ng SigmaPCB/g and 0.189 ng SigmaDDT/g). Mean SigmaPCB concentrations in oil supplements were 34.5, 24.2, 25.1, 95.3, 12.0, 5260, 321, and 519 ng/g in unidentified fish, mixed fish containing no salmon, mixed fish with salmon, salmon, vegetable with mixed fish, shark, menhaden (n = 1), and seal (n = 1), respectively. Maximum concentrations of the other OCs were generally observed in the seal oil. The hexachlorinated PCB congeners were the dominant contributors to SigmaPCB levels, while SigmaDDT was the greatest contributor to organochlorine levels. Intake estimates were made using maximum dosages on manufacturers' labels and results varied widely due to the large difference in residue concentrations obtained. Average SigmaPCB and SigmaDDT intakes were calculated to be 736 +/- 2840 ng/d and 304 +/- 948 ng/d, respectively. |
nfcorpus-qrel-MED-5091 | Generate text that best answers this question: DHA | Essential n-3 fatty acids in pregnant women and early visual acuity maturation in term infants.
BACKGROUND: Docosahexaenoic acid (DHA) is important to neural development. Whether DHA intakes are low enough in some pregnant women to impair infant development is uncertain. OBJECTIVE: We sought to determine whether DHA deficiency occurs in pregnant women and contributes to poor infant development. DESIGN: Biochemical cutoffs, dietary intakes, or developmental scores indicative of DHA deficiency are not defined. Infant development has a distribution in which an individual's potential development is unknown. This was a randomized intervention to establish a distribution of developmental scores for infants of women with DHA intakes considered to be above requirements against which to compare the development of infants of mothers consuming their usual diet. DHA (400 mg/d; n = 67) or a placebo (n = 68) was consumed by the women from 16 wk gestation until delivery. We determined maternal red blood cell ethanolamine phosphoglyceride fatty acids, dietary intakes at 16 and 36 wk gestation, and infant visual acuity at 60 d of age. RESULTS: We described an approach to identify DHA deficiency when biochemical and functional markers of deficiency are unknown. In multivariate analyses, infant visual acuity was related to sex (beta = 0.660, SE = 0.93, and odds ratio = 1.93) and maternal DHA intervention (beta = 1.215, SE = 1.64, and odds ratio = 3.37). More infant girls in the placebo than in the DHA intervention group had a visual acuity below average (P = 0.048). Maternal red blood cell ethanolamine phosphoglyceride docosatetraenoic acid was inversely related to visual acuity in boys (rho = -0.37, P < 0.05) and girls (rho = -0.48, P < 0.01). CONCLUSIONS: These studies suggest that some pregnant women in our study population were DHA-deficient. |
nfcorpus-qrel-MED-5093 | Generate text that best answers this question: DHA | Maternal consumption of a docosahexaenoic acid-containing functional food during pregnancy: benefit for infant performance on problem-solving but n...
BACKGROUND: There are few studies reporting on docosahexaenoic acid (DHA, 22:6n-3) supplementation during pregnancy and infant cognitive function. DHA supplementation in pregnancy and infant problem solving in the first year have not been investigated. OBJECTIVE: We tested the hypothesis that infants born to women who consumed a DHA-containing functional food during pregnancy would demonstrate better problem-solving abilities and recognition memory than would infants born to women who consumed the placebo during pregnancy. DESIGN: In a double-blind, placebo-controlled, randomized trial, pregnant women consumed a DHA-containing functional food or a placebo from gestation week 24 until delivery. Study groups received DHA-containing cereal-based bars (300 mg DHA/92-kcal bar; average consumption: 5 bars/wk; n = 14) or cereal-based placebo bars (n = 15). The Infant Planning Test and Fagan Test of Infant Intelligence were administered to infants at age 9 mo. The problem-solving trial included a support step and a search step. The procedure was scored on the basis of the infant's performance on each step and on the entire problem (intention score and total intentional solutions). Scores were generated on the basis of the cumulative performance of the infant on 5 trials. RESULTS: Treatment had significant effects on the performance of problem-solving tasks: total intention score (P = 0.017), total intentional solutions (P = 0.011), and number of intentional solutions on both cloth (P = 0.008) and cover (P = 0.004) steps. There were no significant differences between groups in any measure of Fagan Test of Infant Intelligence. CONCLUSION: These data point to a benefit for problem solving but not for recognition memory at age 9 mo in infants of mothers who consumed a DHA-containing functional food during pregnancy. |
nfcorpus-qrel-MED-5097 | Generate text that best answers this question: DHA | Fish consumption, methylmercury and child neurodevelopment
Purpose of review To summarize recent evidence regarding associations of early life exposure to mercury from maternal fish consumption during pregnancy, thimerosal in vaccines and dental amalgam with child neurodevelopment. Recent findings Recent publications have built upon previous evidence demonstrating mild detrimental neurocognitive effects from prenatal methylmercury exposure from maternal fish consumption during pregnancy. New studies examining the effects of prenatal fish consumption as well as methylmercury suggest there are benefits from prenatal fish consumption, but also that consumption of fish high in mercury should be avoided. Future studies incorporating information on both the methylmercury and the docosahexaenoic acid contained within fish will help to refine recommendations to optimize outcomes for mothers and children. Additional recent studies have supported the safety of vaccines containing thimerosal and of dental amalgam for repair of dental caries in children. Summary Exposure to mercury may harm child development. Interventions intended to reduce exposure to low levels of mercury in early life must, however, be carefully evaluated in consideration of the potential attendant harm from resultant behavior changes, such as reduced docosahexaenoic acid exposure from lower seafood intake, reduced uptake of childhood vaccinations and suboptimal dental care. |
nfcorpus-qrel-MED-5098 | Generate text that best answers this question: DHA | A risk-benefit analysis of French high fish consumption: a QALY approach.
The health risk and the nutritional benefit of a food are usually assessed separately. Toxicologists recommend limiting the consumption of certain fish because of methylmercury; while nutritionists recommend eating more oily fish because of omega 3. A common evaluation is imperative to provide coherent recommendations. In order to evaluate the risks along with the benefits related to fish consumption, a common metric based on the quality-adjusted life year (QALY) method has been used. The impact of a theoretical change from a medium n-3 PUFAs intake to a high intake is studied, in terms of the cardiovascular system (CHD mortality, stroke mortality and morbidity) and on fetal neuronal development (IQ loss or gain). This application can be considered as a sensitive analysis of the model used and looks at the impact of changing the dose-response relationships between cardiovascular diseases and n-3 PUFAs intakes. Results show that increasing fish consumption may have a beneficial impact on health. However, the confidence interval of the overall estimation has a negative lower bound, which means that this increase in fish consumption may have a negative impact due to MeHg contamination. Some limits of the QALY approach are identified. The first concerns determination of the dose-response relationships. The second concerns the economic origins of the approach and of individual preferences. Finally, since only one beneficial aspect and one risk element were studied, consideration should be given to how other beneficial and risk components may be integrated in the model. |
nfcorpus-qrel-MED-5099 | Generate text that best answers this question: DHA | Nutrient and methyl mercury exposure from consuming fish.
There is controversy about the risks and benefits of consuming fish. Fish consumption provides nutrients, some of which are essential for brain growth and development. All fish, however, contain methyl mercury (MeHg), a known neurotoxicant. The toxic effect of MeHg seems most damaging during brain development, and thus, prenatal exposure is of greatest concern. At present the level of prenatal exposure associated with risk to a child's neurodevelopment is not known. Balancing the rewards and possible risks of fish consumption presents a dilemma to consumers and regulatory authorities. We review the nutrients in fish that are important in brain development and the current evidence of risk from MeHg at exposure levels achieved by consuming fish. We then review the findings from a large prospective cohort study of a population that consumes fish daily, the Seychelles Child Development Study. The MeHg content of the fish consumed in the Seychelles is similar to that of ocean fish available in industrialized countries, so they represent a sentinel population for any risk from fish consumption. In the Seychelles, evaluations of the children through 9 y of age show no consistent pattern of adverse associations with prenatal MeHg exposure. Recent studies in the Seychelles have focused on nutrients in fish that might influence a child's development, including long-chain polyunsaturated fatty acids, iodine, iron, and choline. Preliminary findings from this study suggest that the beneficial influence of nutrients from fish may counter any adverse effects of MeHg on the developing nervous system. |
nfcorpus-qrel-MED-5100 | Generate text that best answers this question: DHA | Public health guidance on cardiovascular benefits and risks related to fish consumption
Historically, concerns with fish consumption have addressed risks from contaminants (e.g., methylmercury (MeHg), and PCBs). More recently public health concerns have widened in appreciation of the specific benefits of fish consumption such as those arising from polyunsaturated fatty acids (PUFAs) in fish oil. Fish contains varying levels of PUFAs and MeHg. Since both address the same health outcomes (in opposite directions) and occur together in fish, great care must be exercised in providing public health guidance. Mozaffarian and Rimm in a recent article (JAMA. 2006, 296:1885–99) have made a strong case for the beneficial effects of PUFAs in reducing the risk of coronary heart disease, but at the same time, have also broadly discounted the increased risks of coronary heart disease posed by MeHg in fish, stating that "... among adults... the benefits of fish intake exceed the potential risks." This conclusion appears to be based on an inaccurate and insufficiently critical analysis of the literature. This literature is re-examined in light of their conclusions, and the available and appropriate public health options are considered. |
nfcorpus-qrel-MED-5101 | Generate text that best answers this question: DHA | Nutrient and contaminant tradeoffs: exchanging meat, poultry, or seafood for dietary protein.
When making food choices, consumers are faced with the dilemma of reconciling differences between health benefits and exposure to potential toxins. Analyses to estimate likely intake and exposure outcomes for young children and women of child-bearing age shows that seafood, chicken, and beef, while approximately equivalent in protein, vary in key nutrients of importance as well as in levels of certain contaminants. Increasing the variety of choices among meats, poultry, and seafood and consuming them in amounts consistent with current dietary guidelines and advisories will contribute toward meeting nutritional needs while reducing exposure to any single type of contaminant. |
nfcorpus-qrel-MED-5102 | Generate text that best answers this question: DHA | Simulated impact of a fish based shift in the population n--3 fatty acids intake on exposure to dioxins and dioxin-like compounds.
Due to the favourable health effects of LC n-3 PUFAs, marine products have been recognised as a food group of special importance in the human diet. However, seafood is susceptible to contamination by lipophilic organic pollutants. The objective of this study was to evaluate intake levels of PCDDs, PCDFs and dioxin-like PCBs, by a probabilistic Monte Carlo procedure, in relation to the recommendation on LC n-3 PUFAs given by Belgian Federal Health Council. Regarding the recommendation, two scenarios were developed differing in LC n-3 PUFAs intake: a 0.3 E% and a 0.46 E% scenario. Total exposure to dioxins and dioxin-like substances in the 0.3 E% LC n-3 PUFAs scenario ranges from 2.31 pg TEQ/kg bw/day at the 5th percentile, over 4.37 pg TEQ/kgbw/day at the 50th percentile to 8.41 pg TEQ/kgbw/day at the 95th percentile. In the 0.46 E% LC n-3 PUFAs scenario, 5, 50 and 95th percentile are exposed to 2.74, 5.52 and 9.98 pg TEQ/kgbw/day, respectively. Therefore, if the recommended LC n-3 PUFAs intake would be based on fish consumption as the only extra source, the majority of the study population would exceed the proposed health based guidance values for dioxins and dioxin-like substances. |
nfcorpus-qrel-MED-5104 | Generate text that best answers this question: DHA | Brominated flame retardants in US food.
We and others recently began studying brominated flame retardant levels in various matrices in the US including human milk and other food. This paper reviews the food studies. In our studies, ten to thirteen polybrominated diphenyl ether (PBDE) congeners were measured, usually including BDE 209. All US women's milk samples were contaminated with PBDEs from 6 to 419 ng/g, lipid, orders of magnitude higher than levels reported in European studies, and are the highest reported worldwide. We compared our market basket studies of meat, fish and dairy products with other US food studies of meat and fish. US studies showed somewhat higher levels of PBDEs than reported elsewhere. Fish were most highly contaminated (median 616 pg/g), then meat (median190 pg/g) and dairy products (median 32.2 pg/g). However, unlike some European countries where fish predominates, dietary intake of PBDEs in the US is mostly from meat, then fish and then dairy products. Broiling can decrease the amount of PBDEs per serving. We also measured levels of hexabromocyclododecane (HBCD), another brominated flame retardant, in human milk. The levels are lower than PBDEs, 0.16-1.2 ng/g, similar to European levels, unlike PBDEs where US levels are much higher than European levels. |
nfcorpus-qrel-MED-4686 | Generate text that best answers this question: dietary scoring | Proposal for a dietary "phytochemical index".
There is ample reason to believe that diets rich in phytochemicals provide protection from vascular diseases and many cancers; direct antioxidant activity as well as modulation of enzyme expression or hormone activity contribute to this effect. Phytochemicals derived from diverse foods presumably can interact additively and (possibly) synergistically; thus, the total dietary load of phytochemicals may have important implications for health. As a means of very roughly quantifying this load, a "phytochemical index" (PI) is proposed, defined as the percent of dietary calories derived from foods rich in phytochemicals. Calories derived from fruits, vegetables (excluding potatoes), legumes, whole grains, nuts, seeds, fruit/vegetable juices, soy products, wine, beer, and cider - and foods compounded therefrom - would be counted in this index. Partial credit could be given for antioxidant-rich extra virgin olive oil. Other added oils, refined sugars, refined grains, potato products, hard liquors, and animal products - regrettably, the chief sources of calories in typical Western diets - would be excluded. Although the PI would provide only a very rough approximation of the quantity or quality of phytochemical nutrition, it nonetheless could aid epidemiologists in exploring the health consequences of diets high in phytochemical-rich plant foods, and could also help clinical nutritionists in their efforts to improve the phytochemical nutrition of their clients. |
nfcorpus-qrel-MED-4380 | Generate text that best answers this question: domoic acid | Domoic acid and human exposure risks: a review.
Domoic acid is a potent neurotoxin that is naturally produced by several diatom species of the genus Pseudo-nitzschia. The toxin acts as a glutamate agonist and is excitotoxic in the vertebrate central nervous system and other glutamate receptor-rich organs. Human exposure to domoic acid occurs via the consumption of contaminated shellfish that have accumulated the toxin while filter feeding on toxigenic phytoplankton during blooms. The first reported human domoic acid poisoning event occurred in Canada in 1987 during which clinical signs of acute toxicity such as gastrointestinal distress, confusion, disorientation, memory loss, coma and death were observed. The illness was named amnesic shellfish poisoning (ASP) and due to effective seafood monitoring programs there have been no documented ASP cases since 1987. However, domoic acid poisoning has a significant effect on marine wildlife and multiple poisoning events have occurred in marine birds and mammals over the last few decades. Currently, domoic acid producing diatom blooms are thought to be increasing in frequency world wide, posing an increasing threat to wildlife and human health. Of particular concern are the potential impacts of long-term low-level exposure in "at risk" human populations. The impacts of repetitive low-level domoic acid exposure are currently unknown. This review provides a basic description of the mechanism of action of domoic acid as well as a synthesis of information pertaining to domoic acid exposure routes, toxin susceptibility, and the importance of effective monitoring programs. The importance of investigating the potential human health impacts of long-term low-level domoic acid exposure in "at risk" human populations is also discussed. Published by Elsevier Ltd. |
nfcorpus-qrel-MED-4381 | Generate text that best answers this question: domoic acid | Amnesic shellfish poison.
Amnesic shellfish poisoning (ASP) is caused by consumption of shellfish that have accumulated domoic acid, a neurotoxin produced by some strains of phytoplankton. The neurotoxic properties of domoic acid result in neuronal degeneration and necrosis in specific regions of the hippocampus. A serious outbreak of ASP occurred in Canada in 1987 and involved 150 reported cases, 19 hospitalisations and 4 deaths after consumption of contaminated mussels. Symptoms ranged from gastrointestinal disturbances, to neurotoxic effects such as hallucinations, memory loss and coma. Monitoring programmes are in place in numerous countries worldwide and closures of shellfish harvesting areas occur when domoic acid concentrations exceed regulatory limits. This paper reviews the chemistry, sources, metabolism and toxicology of domoic acid as well as human case reports of ASP and discusses a possible mechanism of toxicity. |
nfcorpus-qrel-MED-2763 | Generate text that best answers this question: Dr. Dean Ornish | Facing the facelessness of public health: what's the public got to do with it?
Despite compelling statistics that show we could eliminate 80%of all heart disease and strokes, 90% of all diabetes, and 60% of all cancers with basic lifestyle changes, we have failed to motivate the public to make these changes and failed to motivate policy makers to make healthy choices the easiest choice. Dr. Katz suggests we have failed because we have focused too much on statistics and too little on passion. He implores all of us to tap into people's passion by connecting each of these statistics with a human story. |
nfcorpus-qrel-MED-3780 | Generate text that best answers this question: Dr. Dean Ornish | Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease
Metabolomics studies hold promise for discovery of pathways linked to disease processes. Cardiovascular disease (CVD) represents the leading cause of death and morbidity worldwide. A metabolomics approach was used to generate unbiased small molecule metabolic profiles in plasma that predict risk for CVD. Three metabolites of the dietary lipid phosphatidylcholine, namely choline, trimethylamine N-oxide (TMAO), and betaine, were identified and then shown to predict risk for CVD in an independent large clinical cohort. Dietary supplementation of mice with choline, TMAO or betaine promoted up-regulation of multiple macrophage scavenger receptors linked to atherosclerosis, and supplementation with choline or TMAO promoted atherosclerosis. Studies using germ-free mice confirmed a critical role for dietary choline and gut flora in TMAO production, augmented macrophage cholesterol accumulation and foam cell formation. Suppression of intestinal microflora in atherosclerosis-prone mice inhibited dietary choline-enhanced atherosclerosis. Genetic variations controlling expression of flavin monooxygenases (FMOs), an enzymatic source of TMAO, segregated with atherosclerosis in hyperlipidemic mice. Discovery of a relationship between gut flora-dependent metabolism of dietary phosphatidylcholine and CVD pathogenesis provides opportunities for development of both novel diagnostic tests and therapeutic approaches for atherosclerotic heart disease. |
nfcorpus-qrel-MED-3784 | Generate text that best answers this question: Dr. Dean Ornish | Choline and betaine intake and the risk of colorectal cancer in men
Dietary choline and betaine have been hypothesized to decrease the risk of cancer because of their role as methyl donors in the one-carbon metabolism. However, it remains unknown whether dietary intake of choline and betaine is associated with colorectal cancer risk. We prospectively examined the associations between dietary choline and betaine intake and risk of colorectal cancer in men in the Health Professionals Follow-up Study. We followed 47,302 men and identified a total of 987 incident colorectal cancer cases from 1986 to 2004. We assessed dietary and supplemental choline and betaine intake every four years using a validated semi-quantitative food frequency questionnaire. The Cox proportional hazards model was used to estimate multivariate relative risks (RRs) and 95% confidence intervals (95% CIs). All statistical tests were two-sided. We did not find any statistically significant associations between choline intake or betaine intake and risk of colorectal cancer. Comparing the top quintile with bottom quintile, multivariate RRs (95% CI) were 0.97 (0.79-1.20; Ptrend = 0.87) for choline intake and 0.94 (0.77-1.16; Ptrend = 0.79) for betaine intake. Similarly, we observed no associations between colorectal cancer risk and choline from free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine, or sphingomyelin. Our data do not support that choline and betaine intake is inversely associated with colorectal cancer risk. |
nfcorpus-qrel-MED-3242 | Generate text that best answers this question: Dr. Dean Ornish | Macronutrient intake and risk of urothelial cell carcinoma in the European prospective investigation into cancer and nutrition.
Previous studies have suggested that dietary factors may be important in the development of bladder cancer. We examined macronutrient intake in relation to risk of urothelial cell carcinoma among 469,339 men and women in the European Prospective Investigation into Cancer and Nutrition. Associations were examined using Cox regression, stratified by sex, age at recruitment and centre and further adjusted for smoking status and duration, body mass index and total energy intake. After an average of 11.3 years of follow-up, 1,416 new cases of urothelial cell carcinoma were identified. After allowing for measurement error, a 3% increase in the consumption of energy intake from animal protein was associated with a 15% higher risk (95% confidence interval [CI]: 3-30%; p(trend) = 0.01) and a 2% increase in energy from plant protein intake was associated with a 23% lower risk (95% CI: 36-7%, p(trend) = 0.006). Dietary intake of fat, carbohydrate, fibre or calcium was not associated with risk. These findings suggest that animal and/or plant protein may affect the risk of urothelial cell carcinoma, and examination of these associations in other studies is needed. Copyright © 2012 UICC. |
nfcorpus-qrel-MED-3244 | Generate text that best answers this question: Dr. Dean Ornish | A Novel Measure of Dietary Change in a Prostate Cancer Dietary Program Incorporating Mindfulness Training
Diet may represent a modifiable prostate cancer (CaP) risk factor, but a vegetable-based prostate-healthy diet is a major change for most men. We used a ratio of animal:vegetable proteins (A:V ratio) to evaluate whether a comprehensive dietary change was self-sustaining following completion of 11 weekly dietary and cooking classes that integrated mindfulness training (MT). Thirty-six men with recurring CaP were randomized to the intervention or wait-list control. Assessments were at baseline, three months and six months. Of the 17 men randomized to the intervention, 14 completed the requirements. Nineteen were randomized to control and 17 completed requirements. Compared to controls, a significant post-intervention (3 months) decrease in A:V ratio in the intervention group (p=.01) was self-maintained 3 months post-intervention (p=0.049). At each assessment, the A:V ratio was correlated with lycopene, fiber, saturated fat, and dietary cholesterol; four dietary components linked to clinically relevant outcomes in CaP. Change in A:V ratio was also significantly correlated with changes in fiber, saturated fat and dietary cholesterol intake. Participants reported regular MT practice and there was a significant correlation between MT practice and changes in both initiation and maintenance of the change in the A:V ratio. These pilot results provide encouraging evidence for the feasibility of a dietary program that includes MT in supporting dietary change for men with recurrent CaP and invite further study to explore the possible role of MT as a means of supporting both initiation of dietary changes and maintenance of those changes over time. |
nfcorpus-qrel-MED-3790 | Generate text that best answers this question: Dr. Dean Ornish | Intakes of meat, fish, poultry, and eggs and risk of prostate cancer progression
Background: Processed meat and fish have been shown to be associated with the risk of advanced prostate cancer, but few studies have examined diet after prostate cancer diagnosis and risk of its progression. Objective: We examined the association between postdiagnostic consumption of processed and unprocessed red meat, fish, poultry, and eggs and the risk of prostate cancer recurrence or progression. Design: We conducted a prospective study in 1294 men with prostate cancer, without recurrence or progression as of 2004–2005, who were participating in the Cancer of the Prostate Strategic Urologic Research Endeavor and who were followed for an average of 2 y. Results: We observed 127 events (prostate cancer death or metastases, elevated prostate-specific antigen concentration, or secondary treatment) during 2610 person-years. Intakes of processed and unprocessed red meat, fish, total poultry, and skinless poultry were not associated with prostate cancer recurrence or progression. Greater consumption of eggs and poultry with skin was associated with 2-fold increases in risk in a comparison of extreme quantiles: eggs [hazard ratio (HR): 2.02; 95% CI: 1.10, 3.72; P for trend = 0.05] and poultry with skin (HR: 2.26; 95% CI: 1.36, 3.76; P for trend = 0.003). An interaction was observed between prognostic risk at diagnosis and poultry. Men with high prognostic risk and a high poultry intake had a 4-fold increased risk of recurrence or progression compared with men with low/intermediate prognostic risk and a low poultry intake (P for interaction = 0.003). Conclusions: Our results suggest that the postdiagnostic consumption of processed or unprocessed red meat, fish, or skinless poultry is not associated with prostate cancer recurrence or progression, whereas consumption of eggs and poultry with skin may increase the risk. |
nfcorpus-qrel-MED-3245 | Generate text that best answers this question: Dr. Dean Ornish | Vegetable and fruit intake after diagnosis and risk of prostate cancer progression
Cruciferous vegetables, tomato sauce, and legumes have been associated with reduced risk of incident advanced prostate cancer. In vitro and animal studies suggest these foods may inhibit progression of prostate cancer, but there are limited data in men. Therefore, we prospectively examined whether intake of total vegetables, and specifically cruciferous vegetables, tomato sauce, and legumes, after diagnosis reduce risk of prostate cancer progression among 1,560 men diagnosed with non-metastatic prostate cancer and participating in the Cancer of the Prostate Strategic Urologic Research Endeavor, a United States prostate cancer registry. As a secondary analysis, we also examined other vegetable sub-groups, total fruit, and subgroups of fruits. The participants were diagnosed primarily at community-based clinics and followed from 2004–2009. We assessed vegetable and fruit intake via a semi-quantitative food frequency questionnaire, and ascertained prostate cancer outcomes via urologist report and medical records. We observed 134 events of progression (53 biochemical recurrences, 71 secondary treatments likely due to recurrence, six bone metastases, four prostate cancer deaths) during 3,171 person-yrs. Men in the fourth quartile of post-diagnostic cruciferous vegetable intake had a statistically significant 59% decreased risk of prostate cancer progression compared to men in the lowest quartile (hazard ratio (HR): 0.41; 95% confidence interval (CI): 0.22, 0.76; p-trend: 0.003). No other vegetable or fruit group was statistically significantly associated with risk of prostate cancer progression. In conclusion, cruciferous vegetable intake after diagnosis may reduce risk of prostate cancer progression. |
nfcorpus-qrel-MED-5337 | Generate text that best answers this question: Dr. Dean Ornish | Intensive lifestyle changes may affect the progression of prostate cancer.
PURPOSE: Men with prostate cancer are often advised to make changes in diet and lifestyle, although the impact of these changes has not been well documented. Therefore, we evaluated the effects of comprehensive lifestyle changes on prostate specific antigen (PSA), treatment trends and serum stimulated LNCaP cell growth in men with early, biopsy proven prostate cancer after 1 year. MATERIALS AND METHODS: Patient recruitment was limited to men who had chosen not to undergo any conventional treatment, which provided an unusual opportunity to have a nonintervention randomized control group to avoid the confounding effects of interventions such as radiation, surgery or androgen deprivation therapy. A total of 93 volunteers with serum PSA 4 to 10 ng/ml and cancer Gleason scores less than 7 were randomly assigned to an experimental group that was asked to make comprehensive lifestyle changes or to a usual care control group. RESULTS: None of the experimental group patients but 6 control patients underwent conventional treatment due to an increase in PSA and/or progression of disease on magnetic resonance imaging. PSA decreased 4% in the experimental group but increased 6% in the control group (p = 0.016). The growth of LNCaP prostate cancer cells (American Type Culture Collection, Manassas, Virginia) was inhibited almost 8 times more by serum from the experimental than from the control group (70% vs 9%, p <0.001). Changes in serum PSA and also in LNCaP cell growth were significantly associated with the degree of change in diet and lifestyle. CONCLUSIONS: Intensive lifestyle changes may affect the progression of early, low grade prostate cancer in men. Further studies and longer term followup are warranted. |
nfcorpus-qrel-MED-3250 | Generate text that best answers this question: Dr. Dean Ornish | Improvement of endothelium-dependent coronary vasodilation after a single LDL apheresis in patients with hypercholesterolemia.
The purpose of this study was to determine whether a single LDL apheresis would improve impaired endothelium-dependent dilation of the coronary artery in patients with hypercholesterolemia. Hypercholesterolemia is associated with impaired endothelial function, and human studies using cholesterol-lowering drugs indicate that endothelial function in the coronary arteries improves with reduction of serum LDL cholesterol over 6 to 12 months. The internal diameter of the left coronary artery and the coronary blood flow were measured by intracoronary Doppler-wire measurement and quantitative angiography before and immediately after a single LDL apheresis in a population of 15 patients with familial hypercholesterolemia. Endothelium-dependent vasodilation was assessed by intracoronary infusion of acetylcholine (1, 10, and 50 microg/min), and endothelium-independent vasodilation was assessed by intracoronary bolus infusion of isosorbide dinitrate (2.5 mg) or papaverine (10 mg). A single 3-hour LDL apheresis reduced serum LDL cholesterol by an average of 86.6 +/- 1.7%. After the LDL apheresis, the changes in the coronary artery diameter and coronary blood flow in response to an infusion of 50 microg/min of acetylcholine increased significantly compared to the pre-apheresis values (from -19.7 +/- 4.8 to -2.9 +/- 3.0% [P < 0.01] and from 80.7 +/- 27.6 to 155.3 +/- 23.5% [P < 0.01], respectively). The LDL apheresis did not significantly change the response of either parameter to infusion with isosorbide dinitrate or papaverine. The endothelial function of the epicardial coronary artery and the coronary microvasculature improved in hypercholesterolemic patients after only a single LDL apheresis, a procedure that markedly reduces the serum level of LDL cholesterol. Copyright 2004 Wiley-Liss, Inc. |
nfcorpus-qrel-MED-3251 | Generate text that best answers this question: Dr. Dean Ornish | Association between use of interferon beta and progression of disability in patients with relapsing-remitting multiple sclerosis.
CONTEXT: Interferon beta is widely prescribed to treat multiple sclerosis (MS); however, its relationship with disability progression has yet to be established. OBJECTIVE: To investigate the association between interferon beta exposure and disability progression in patients with relapsing-remitting MS. DESIGN, SETTING, AND PATIENTS: Retrospective cohort study based on prospectively collected data (1985-2008) from British Columbia, Canada. Patients with relapsing-remitting MS treated with interferon beta (n = 868) were compared with untreated contemporary (n = 829) and historical (n = 959) cohorts. MAIN OUTCOME MEASURES: The main outcome measure was time from interferon beta treatment eligibility (baseline) to a confirmed and sustained score of 6 (requiring a cane to walk 100 m; confirmed at >150 days with no measurable improvement) on the Expanded Disability Status Scale (EDSS) (range, 0-10, with higher scores indicating higher disability). A multivariable Cox regression model with interferon beta treatment included as a time-varying covariate was used to assess the hazard of disease progression associated with interferon beta treatment. Analyses also included propensity score adjustment to address confounding by indication. RESULTS: The median active follow-up times (first to last EDSS measurement) were as follows: for the interferon beta-treated cohort, 5.1 years (interquartile range [IQR], 3.0-7.0 years); for the contemporary control cohort, 4.0 years (IQR, 2.1-6.4 years); and for the historical control cohort, 10.8 years (IQR, 6.3-14.7 years). The observed outcome rates for reaching a sustained EDSS score of 6 were 10.8%, 5.3%, and 23.1% in the 3 cohorts, respectively. After adjustment for potential baseline confounders (sex, age, disease duration, and EDSS score), exposure to interferon beta was not associated with a statistically significant difference in the hazard of reaching an EDSS score of 6 when either the contemporary control cohort (hazard ratio, 1.30; 95% CI, 0.92-1.83; P = .14) or the historical control cohort (hazard ratio, 0.77; 95% CI, 0.58-1.02; P = .07) were considered. Further adjustment for comorbidities and socioeconomic status, where possible, did not change interpretations, and propensity score adjustment did not substantially change the results. CONCLUSION: Among patients with relapsing-remitting MS, administration of interferon beta was not associated with a reduction in progression of disability. |
nfcorpus-qrel-MED-3247 | Generate text that best answers this question: Dr. Dean Ornish | Evidence Report: The efficacy and safety of mitoxantrone (Novantrone) in the treatment of multiple sclerosis
Objective: The chemotherapeutic agent mitoxantrone was approved for use in multiple sclerosis (MS) in 2000. After a review of all the available evidence, the original report of the Therapeutics and Technology Assessment Subcommittee in 2003 concluded that mitoxantrone probably reduced clinical attack rates, MRI activity, and disease progression. Subsequent reports of decreased systolic function, heart failure, and leukemia prompted the US Food and Drug Administration to institute a “black box” warning in 2005. This review was undertaken to examine the available literature on the efficacy and safety of mitoxantrone use in patients with MS since the initial report. Methods: Relevant articles were obtained through a review of the medical literature and the strength of the available evidence was graded according to the American Academy of Neurology evidence classification scheme. Results: The accumulated Class III and IV evidence suggests an increased incidence of systolic dysfunction and therapy-related acute leukemia (TRAL) with mitoxantrone therapy. Systolic dysfunction occurs in ∼12% of patients with MS treated with mitoxantrone, congestive heart failure occurs in ∼0.4%, and leukemia occurs in ∼0.8%. The number needed to harm is 8 for systolic dysfunction and 123 for TRAL. There is no new efficacy evidence that would change the recommendation from the previous report. Conclusions: The risk of systolic dysfunction and leukemia in patients treated with mitoxantrone is higher than suggested at the time of the previous report, although comprehensive postmarketing surveillance data are lacking. GLOSSARY |
nfcorpus-qrel-MED-3248 | Generate text that best answers this question: Dr. Dean Ornish | Retinal arterial changes correlate with cerebral small-vessel disease.
OBJECTIVE: To examine the relation between retinal artery disease and cerebral small-vessel disease (SVD). METHODS: In a prospective cohort of patients with symptomatic atherosclerotic disease, the authors performed retinal photographs and brain MRI. Two ophthalmologists, not aware of the MR results, independently assessed retinal arterial narrowing, crossings, sclerosis, and tortuosity according to standard scoring lists. Two observers independently assessed white matter lesions (WML) and lacunar infarcts on the MR images. Lesions were considered abnormal only when both ophthalmologists or MR raters agreed. Cerebral SVD was defined as the presence of WML or lacunar infarcts. RESULTS: In 179 patients, retinal photographs and brain MRI were performed. Of the 108 patients with MR signs of SVD, 92% had at least one retinal vascular abnormality; of the 71 patients without SVD, 77% had retinal pathology (p < 0.01). All types of retinal vascular pathology occurred more frequently in patients with SVD, but only retinal arterial narrowing and sclerosis differed significantly. In the 109 normotensive patients, the presence of any retinal vascular change correlated with signs of SVD (p = 0.01). CONCLUSION: Pathologic changes in the retinal arteries parallel changes in the small cerebral arteries that cause WML and lacunes, both in hypertensive and in normotensive patients. |
nfcorpus-qrel-MED-3249 | Generate text that best answers this question: Dr. Dean Ornish | Effect of low saturated fat diet in early and late cases of multiple sclerosis.
144 multiple sclerosis patients took a low-fat diet for 34 years. For each of three categories of neurological disability (minimum, moderate, severe) patients who adhered to the prescribed diet (less than or equal to 20 g fat/day) showed significantly less deterioration and much lower death rates than did those who consumed more fat than prescribed (greater than 20 g fat/day). The greatest benefit was seen in those with minimum disability at the start of the trial; in this group, when those who died from non-MS diseases were excluded from the analysis, 95% survived and remained physically active. |
nfcorpus-qrel-MED-3254 | Generate text that best answers this question: Dr. Dean Ornish | Relation of serum lipoprotein levels and systolic blood pressure to early atherosclerosis. The Bogalusa Heart Study.
We assessed the relation of risk factors for cardiovascular disease to early atherosclerotic lesions in the aorta and coronary arteries in 35 persons (mean age at death, 18 years). Aortic involvement with fatty streaks was greater in blacks than in whites (37 vs. 17 percent, P less than 0.01). However, aortic fatty streaks were strongly related to antemortem levels of both total and low-density lipoprotein cholesterol (r = 0.67, P less than 0.0001 for each association), independently of race, sex, and age, and were inversely correlated with the ratio of high-density lipoprotein cholesterol to low-density plus very-low-density lipoprotein cholesterol (r = -0.35, P = 0.06). Coronary-artery fatty streaks were correlated with very-low-density lipoprotein cholesterol (r = 0.41, P = 0.04). Mean systolic blood-pressure levels also tended to be higher in the four subjects with coronary-artery fibrous plaques than in those without them: 112 mm Hg as compared with 104 (P = 0.09). These results document the importance of risk-factor levels to early anatomical changes in the aorta and coronary arteries. The progression of fatty streaks to fibrous plaques is uncertain, but these data suggest that a rational approach to the prevention of cardiovascular disease should begin early in life. |
nfcorpus-qrel-MED-3253 | Generate text that best answers this question: Dr. Dean Ornish | Pathobiological determinants of atherosclerosis in youth risk scores are associated with early and advanced atherosclerosis.
OBJECTIVES: Atherosclerosis begins in childhood and progresses during adolescence and young adulthood. The Pathobiological Determinants of Atherosclerosis in Youth Study previously reported risk scores to estimate the probability of advanced atherosclerotic lesions in young individuals aged 15 to 34 years using the coronary heart disease risk factors (gender, age, serum lipoprotein concentrations, smoking, hypertension, obesity, and hyperglycemia). In this study we investigated the relation of these risk scores to the early atherosclerotic lesions. METHODS: We measured atherosclerotic lesions in the left anterior descending coronary artery, right coronary artery, and abdominal aorta and the coronary heart disease risk factors in persons 15 to 34 years of age who died as a result of external causes and were autopsied in forensic laboratories. RESULTS: Risk scores computed from the modifiable risk factors were associated with prevalence of microscopically demonstrable lesions of atherosclerosis (American Heart Association grade 1) in the left anterior descending coronary artery and with the extent of the earliest detectable gross lesion (fatty streaks) in the right coronary artery and abdominal aorta. Risk scores computed from the modifiable risk factors also were associated with prevalence of lesions of higher degrees of microscopic severity (intermediate as well as advanced) in the left anterior descending coronary artery and with extent of lesions of higher degrees of severity (intermediate and raised lesions) in the right coronary artery and abdominal aorta. CONCLUSIONS: Risk scores calculated from traditional coronary heart disease risk factors to identify individual young persons with high probability of having advanced atherosclerotic lesions also are associated with earlier atherosclerotic lesions, including the earliest anatomically demonstrable atherosclerotic lesion. These results support lifestyle modification in youth to prevent development of the initial lesions and the subsequent progression to advanced lesions and, thereafter, to prevent or delay coronary heart disease. |
nfcorpus-qrel-MED-1399 | Generate text that best answers this question: Dr. Dean Ornish | Mediterranean diet, traditional risk factors, and the rate of cardiovascular complications after myocardial infarction: final report of the Lyon Di...
BACKGROUND: The Lyon Diet Heart Study is a randomized secondary prevention trial aimed at testing whether a Mediterranean-type diet may reduce the rate of recurrence after a first myocardial infarction. An intermediate analysis showed a striking protective effect after 27 months of follow-up. This report presents results of an extended follow-up (with a mean of 46 months per patient) and deals with the relationships of dietary patterns and traditional risk factors with recurrence. METHODS AND RESULTS: Three composite outcomes (COs) combining either cardiac death and nonfatal myocardial infarction (CO 1), or the preceding plus major secondary end points (unstable angina, stroke, heart failure, pulmonary or peripheral embolism) (CO 2), or the preceding plus minor events requiring hospital admission (CO 3) were studied. In the Mediterranean diet group, CO 1 was reduced (14 events versus 44 in the prudent Western-type diet group, P=0.0001), as were CO 2 (27 events versus 90, P=0.0001) and CO 3 (95 events versus 180, P=0. 0002). Adjusted risk ratios ranged from 0.28 to 0.53. Among the traditional risk factors, total cholesterol (1 mmol/L being associated with an increased risk of 18% to 28%), systolic blood pressure (1 mm Hg being associated with an increased risk of 1% to 2%), leukocyte count (adjusted risk ratios ranging from 1.64 to 2.86 with count >9x10(9)/L), female sex (adjusted risk ratios, 0.27 to 0. 46), and aspirin use (adjusted risk ratios, 0.59 to 0.82) were each significantly and independently associated with recurrence. CONCLUSIONS: The protective effect of the Mediterranean dietary pattern was maintained up to 4 years after the first infarction, confirming previous intermediate analyses. Major traditional risk factors, such as high blood cholesterol and blood pressure, were shown to be independent and joint predictors of recurrence, indicating that the Mediterranean dietary pattern did not alter, at least qualitatively, the usual relationships between major risk factors and recurrence. Thus, a comprehensive strategy to decrease cardiovascular morbidity and mortality should include primarily a cardioprotective diet. It should be associated with other (pharmacological?) means aimed at reducing modifiable risk factors. Further trials combining the 2 approaches are warranted. |
nfcorpus-qrel-MED-1393 | Generate text that best answers this question: Dr. Dean Ornish | Changes in ultrasound-assessed carotid intima-media thickness and plaque with a Mediterranean diet: a substudy of the PREDIMED trial.
OBJECTIVE: The Prevención con Dieta Mediterránea (PREDIMED) trial showed that a Mediterranean diet (MedDiet) supplemented with either extra virgin olive oil or 30 g/d of mixed nuts reduced incident cardiovascular events compared with a control (low fat) diet. The mechanisms of cardiovascular protection afforded by MedDiets remain to be uncovered. We assessed the effect of both supplemented MedDiets on internal carotid intima-media thickness (ICA-IMT) and plaque height, the ultrasound features that best predict future cardiovascular events, in subjects at high cardiovascular risk. APPROACH AND RESULTS: In a PREDIMED subcohort (n=175), plaque height and carotid IMT of 3 prespecified segments (ICA, bifurcation, and common) were sonographically assessed at baseline and after intervention for a mean of 2.4 years. We evaluated 164 subjects with complete data. In a multivariate model, mean ICA-IMT progressed in the control diet group (mean [95% confidence interval], 0.052 mm [-0.014 to 0.118 mm]), whereas it regressed in the MedDiet+nuts group (-0.084 mm [-0.158 to -0.010 mm]; P=0.024 versus control). Similar results were observed for maximum ICA-IMT (control, 0.188 mm [0.077 to 0.299 mm]; MedDiet+nuts, -0.030 mm [-0.153 to 0.093 mm]; P=0.034) and maximum plaque height (control, 0.106 mm [0.001 to 0.210 mm]; MedDiet+nuts, -0.091 mm [-0.206 to 0.023 mm]; P=0.047). There were no changes in ICA-IMT or plaque after the MedDiet+extra virgin olive oil. CONCLUSIONS: Compared with a control diet, consumption of a MedDiet supplemented with nuts is associated with delayed progression of ICA-IMT and plaque. The results contribute mechanistic evidence for the reduction of cardiovascular events observed in the PREDIMED trial. CLINICAL TRIAL REGISTRATION URL: http://www.controlled-trials.com. Unique identifier: ISRCTN35739639. |
nfcorpus-qrel-MED-1394 | Generate text that best answers this question: Dr. Dean Ornish | Primary prevention of cardiovascular disease with a Mediterranean diet.
BACKGROUND: Observational cohort studies and a secondary prevention trial have shown an inverse association between adherence to the Mediterranean diet and cardiovascular risk. We conducted a randomized trial of this diet pattern for the primary prevention of cardiovascular events. METHODS: In a multicenter trial in Spain, we randomly assigned participants who were at high cardiovascular risk, but with no cardiovascular disease at enrollment, to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat). Participants received quarterly individual and group educational sessions and, depending on group assignment, free provision of extra-virgin olive oil, mixed nuts, or small nonfood gifts. The primary end point was the rate of major cardiovascular events (myocardial infarction, stroke, or death from cardiovascular causes). On the basis of the results of an interim analysis, the trial was stopped after a median follow-up of 4.8 years. RESULTS: A total of 7447 persons were enrolled (age range, 55 to 80 years); 57% were women. The two Mediterranean-diet groups had good adherence to the intervention, according to self-reported intake and biomarker analyses. A primary end-point event occurred in 288 participants. The multivariable-adjusted hazard ratios were 0.70 (95% confidence interval [CI], 0.54 to 0.92) and 0.72 (95% CI, 0.54 to 0.96) for the group assigned to a Mediterranean diet with extra-virgin olive oil (96 events) and the group assigned to a Mediterranean diet with nuts (83 events), respectively, versus the control group (109 events). No diet-related adverse effects were reported. CONCLUSIONS: Among persons at high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil or nuts reduced the incidence of major cardiovascular events. (Funded by the Spanish government's Instituto de Salud Carlos III and others; Controlled-Trials.com number, ISRCTN35739639.). |
nfcorpus-qrel-MED-1395 | Generate text that best answers this question: Dr. Dean Ornish | Mediterranean alpha-linolenic acid-rich diet in secondary prevention of coronary heart disease.
In a prospective, randomised single-blinded secondary prevention trial we compared the effect of a Mediterranean alpha-linolenic acid-rich diet to the usual post-infarct prudent diet. After a first myocardial infarction, patients were randomly assigned to the experimental (n = 302) or control group (n = 303). Patients were seen again 8 weeks after randomisation, and each year for 5 years. The experimental group consumed significantly less lipids, saturated fat, cholesterol, and linoleic acid but more oleic and alpha-linolenic acids confirmed by measurements in plasma. Serum lipids, blood pressure, and body mass index remained similar in the 2 groups. In the experimental group, plasma levels of albumin, vitamin E, and vitamin C were increased, and granulocyte count decreased. After a mean follow up of 27 months, there were 16 cardiac deaths in the control and 3 in the experimental group; 17 non-fatal myocardial infarction in the control and 5 in the experimental groups: a risk ratio for these two main endpoints combined of 0.27 (95% CI 0.12-0.59, p = 0.001) after adjustment for prognostic variables. Overall mortality was 20 in the control, 8 in the experimental group, an adjusted risk ratio of 0.30 (95% CI 0.11-0.82, p = 0.02). An alpha-linolenic acid-rich Mediterranean diet seems to be more efficient than presently used diets in the secondary prevention of coronary events and death. |
nfcorpus-qrel-MED-1489 | Generate text that best answers this question: Dr. Dean Ornish | A way to reverse CAD?
PURPOSE: Plant-based nutrition achieved coronary artery disease (CAD) arrest and reversal in a small study. However, there was skepticism that this approach could succeed in a larger group of patients. The purpose of our follow-up study was to define the degree of adherence and outcomes of 198 consecutive patient volunteers who received counseling to convert from a usual diet to plant-based nutrition. METHODS: We followed 198 consecutive patients counseled in plant-based nutrition. These patients with established cardiovascular disease (CVD) were interested in transitioning to plant-based nutrition as an adjunct to usual cardiovascular care. We considered participants adherent if they eliminated dairy, fish, and meat, and added oil. RESULTS: Of the 198 patients with CVD, 177 (89%) were adherent. Major cardiac events judged to be recurrent disease totaled one stroke in the adherent cardiovascular participants—a recurrent event rate of .6%, significantly less than reported by other studies of plant-based nutrition therapy. Thirteen of 21 (62%) nonadherent participants experienced adverse events. CONCLUSION: Most of the volunteer patients with CVD responded to intensive counseling, and those who sustained plant-based nutrition for a mean of 3.7 years experienced a low rate of subsequent cardiac events. This dietary approach to treatment deserves a wider test to see if adherence can be sustained in broader populations. Plant-based nutrition has the potential for a large effect on the CVD epidemic. |
nfcorpus-qrel-MED-1397 | Generate text that best answers this question: Dr. Dean Ornish | Omega-3 fatty acids and antioxidants in edible wild plants.
Human beings evolved on a diet that was balanced in the omega-6 and omega-3 polyunsaturated fatty acids (PUFA), and was high in antioxidants. Edible wild plants provide alpha-linolenic acid (ALA) and higher amounts of vitamin E and vitamin C than cultivated plants. In addition to the antioxidant vitamins, edible wild plants are rich in phenols and other compounds that increase their antioxidant capacity. It is therefore important to systematically analyze the total antioxidant capacity of wild plants and promote their commercialization in both developed and developing countries. The diets of Western countries have contained increasingly larger amounts of linoleic acid (LA), which has been promoted for its cholesterol-lowering effect. It is now recognized that dietary LA favors oxidative modification of low density lipoprotein (LDL) cholesterol and increases platelet response to aggregation. In contrast, ALA intake is associated with inhibitory effects on the clotting activity of platelets, on their response to thrombin, and on the regulation of arachidonic acid (AA) metabolism. In clinical studies, ALA contributed to lowering of blood pressure, and a prospective epidemiological study showed that ALA is inversely related to the risk of coronary heart disease in men. Dietary amounts of LA as well as the ratio of LA to ALA appear to be important for the metabolism of ALA to longer-chain omega-3 PUFAs. Relatively large reserves of LA in body fat. as are found in vegans or in the diet of omnivores in Western societies, would tend to slow down the formation of long-chain omega-3 fatty acids from ALA. Therefore, the role of ALA in human nutrition becomes important in terms of long-term dietary intake. One advantage of the consumption of ALA over omega-3 fatty acids from fish is that the problem of insufficient vitamin E intake does not exist with high intake of ALA from plant sources. |
nfcorpus-qrel-MED-1398 | Generate text that best answers this question: Dr. Dean Ornish | Mediterranean diet and cardiovascular disease: historical perspective and latest evidence.
The concept that the Mediterranean diet was associated with a lower incidence of cardiovascular disease (CVD) was first proposed in the 1950s. Since then, there have been randomized controlled trials and large epidemiological studies that reported associations with lower CVD: in 1994 and 1999, the reports of the intermediate and final analyses of the trial Lyon Diet Heart Study; in 2003, a major epidemiological study in Greece showing a strong inverse association between a Mediterranean score and the risk of cardiovascular complications; in 2011-2012, several reports showing that even non-Mediterranean populations can gain benefits from long-term adhesion to the Mediterranean diet; and in 2013, the PREDIMED trial showing a significant risk reduction in a low-risk population. Contrary to the pharmacological approach of cardiovascular prevention, the adoption of the Mediterranean diet has been associated with a significant reduction in new cancers and overall mortality. Thus, in terms of evidence-based medicine, the full adoption of a modern version of the Mediterranean diet pattern can be considered one of the most effective approaches for the prevention of fatal and nonfatal CVD complications. |
nfcorpus-qrel-MED-1400 | Generate text that best answers this question: Dr. Dean Ornish | Accruing evidence on benefits of adherence to the Mediterranean diet on health: an updated systematic review and meta-analysis.
BACKGROUND: The Mediterranean diet has long been reported to be protective against the occurrence of several different health outcomes. OBJECTIVE: We aimed to update our previous meta-analysis of published cohort prospective studies that investigated the effects of adherence to the Mediterranean diet on health status. DESIGN: We conducted a comprehensive literature search through electronic databases up to June 2010. RESULTS: The updated review process showed 7 prospective studies published in the past 2 y that were not included in the previous meta-analysis (1 study for overall mortality, 3 studies for cardiovascular incidence or mortality, 1 study for cancer incidence or mortality, and 2 studies for neurodegenerative diseases). These recent studies included 2 health outcomes not previously investigated (ie, mild cognitive impairment and stroke). The meta-analysis for all studies with a random-effects model that was conducted after the inclusion of these recent studies showed that a 2-point increase in adherence to the Mediterranean diet was associated with a significant reduction of overall mortality [relative risk (RR) = 0.92; 95% CI: 0.90, 0.94], cardiovascular incidence or mortality (RR = 0.90; 95% CI: 0.87, 0.93), cancer incidence or mortality (RR = 0.94; 95% CI: 0.92, 0.96), and neurodegenerative diseases (RR = 0.87; 95% CI: 0.81, 0.94). The meta-regression analysis showed that sample size was the most significant contributor to the model because it significantly influenced the estimate of the association for overall mortality. CONCLUSION: This updated meta-analysis confirms, in a larger number of subjects and studies, the significant and consistent protection provided by adherence to the Mediterranean diet in relation to the occurrence of major chronic degenerative diseases. |
nfcorpus-qrel-MED-1476 | Generate text that best answers this question: Dr. Dean Ornish | Neanderthal cannibalism at Moula-Guercy, Ardèche, France.
The cave site of Moula-Guercy, 80 meters above the modern Rhone River, was occupied by Neanderthals approximately 100,000 years ago. Excavations since 1991 have yielded rich paleontological, paleobotanical, and archaeological assemblages, including parts of six Neanderthals. The Neanderthals are contemporary with stone tools and faunal remains in the same tightly controlled stratigraphic and spatial contexts. The inference of Neanderthal cannibalism at Moula-Guercy is based on comparative analysis of hominid and ungulate bone spatial distributions, modifications by stone tools, and skeletal part representations. |
nfcorpus-qrel-MED-2432 | Generate text that best answers this question: Dr. Dean Ornish | The Garden of Eden--plant based diets, the genetic drive to conserve cholesterol and its implications for heart disease in the 21st century.
It is likely that plant food consumption throughout much of human evolution shaped the dietary requirements of contemporary humans. Diets would have been high in dietary fiber, vegetable protein, plant sterols and associated phytochemicals, and low in saturated and trans-fatty acids and other substrates for cholesterol biosynthesis. To meet the body's needs for cholesterol, we believe genetic differences and polymorphisms were conserved by evolution, which tended to raise serum cholesterol levels. As a result modern man, with a radically different diet and lifestyle, especially in middle age, is now recommended to take medications to lower cholesterol and reduce the risk of cardiovascular disease. Experimental introduction of high intakes of viscous fibers, vegetable proteins and plant sterols in the form of a possible Myocene diet of leafy vegetables, fruit and nuts, lowered serum LDL-cholesterol in healthy volunteers by over 30%, equivalent to first generation statins, the standard cholesterol-lowering medications. Furthermore, supplementation of a modern therapeutic diet in hyperlipidemic subjects with the same components taken as oat, barley and psyllium for viscous fibers, soy and almonds for vegetable proteins and plant sterol-enriched margarine produced similar reductions in LDL-cholesterol as the Myocene-like diet and reduced the majority of subjects' blood lipids concentrations into the normal range. We conclude that reintroduction of plant food components, which would have been present in large quantities in the plant based diets eaten throughout most of human evolution into modern diets can correct the lipid abnormalities associated with contemporary eating patterns and reduce the need for pharmacological interventions. |
nfcorpus-qrel-MED-1478 | Generate text that best answers this question: Dr. Dean Ornish | Paleolithic nutrition: twenty-five years later.
A quarter century has passed since the first publication of the evolutionary discordance hypothesis, according to which departures from the nutrition and activity patterns of our hunter-gatherer ancestors have contributed greatly and in specifically definable ways to the endemic chronic diseases of modern civilization. Refinements of the model have changed it in some respects, but anthropological evidence continues to indicate that ancestral human diets prevalent during our evolution were characterized by much lower levels of refined carbohydrates and sodium, much higher levels of fiber and protein, and comparable levels of fat (primarily unsaturated fat) and cholesterol. Physical activity levels were also much higher than current levels, resulting in higher energy throughput. We said at the outset that such evidence could only suggest testable hypotheses and that recommendations must ultimately rest on more conventional epidemiological, clinical, and laboratory studies. Such studies have multiplied and have supported many aspects of our model, to the extent that in some respects, official recommendations today have targets closer to those prevalent among hunter-gatherers than did comparable recommendations 25 years ago. Furthermore, doubts have been raised about the necessity for very low levels of protein, fat, and cholesterol intake common in official recommendations. Most impressively, randomized controlled trials have begun to confirm the value of hunter-gatherer diets in some high-risk groups, even as compared with routinely recommended diets. Much more research needs to be done, but the past quarter century has proven the interest and heuristic value, if not yet the ultimate validity, of the model. |
nfcorpus-qrel-MED-1479 | Generate text that best answers this question: Dr. Dean Ornish | BEYOND THE PALEOLITHIC PRESCRIPTION: INCORPORATING DIVERSITY AND FLEXIBILITY IN THE STUDY OF HUMAN DIET EVOLUTION
Evolutionary paradigms of human health and nutrition center on the evolutionary discordance or “mismatch” model whereby human bodies, reflecting adaptations established in the Paleolithic era, are ill-suited to modern industrialized diets resulting in rapidly increasing rates of chronic metabolic disease. Whereas this model remains useful, we argue that its utility in explaining the evolution of human dietary tendencies is limited. The assumption that human diets are mismatched to our evolved biology implies that they are instinctual or genetically determined and rooted in the Paleolithic. We review current research indicating that human eating habits are primarily learned through behavioral, social and physiological mechanisms starting in utero and extending throughout the life course. Those adaptations that appear to be strongly genetic likely reflect Neolithic, rather than Paleolithic, adaptations and are significantly influenced by human niche-constructing behavior. Incorporating a broader understanding of the evolved mechanisms by which humans learn and imprint eating habits and the reciprocal effects of those habits on physiology would provide useful tools for structuring more lasting nutrition interventions. |
nfcorpus-qrel-MED-1486 | Generate text that best answers this question: Dr. Dean Ornish | Patient expectations on lipid-lowering drugs.
OBJECTIVE: The objective of this study was to assess expectations of effect when using statins in a treatment population. Further the aim was to examine factors, including history and concurrent risk of coronary heart disease, associated with a higher and lower treatment belief. METHODS: Eight hundred and twenty-nine (829) Swedish patients using statins completed postal questionnaires about their health, life style, cardiovascular risk factors and expectation of the treatment. Expected treatment benefit was used as outcome measurement. RESULTS: A medical history of coronary heart disease did not affect treatment expectations. Patients with a high risk of cardiovascular disease reported a slightly lower expectation of the treatment effect at a 10-year perspective (p<0.01) but not at shorter time perspectives. Low satisfaction with the explanation of the purpose of the treatment and a poor perceived control of own health was associated with a more negative view on treatment benefit. CONCLUSION: The rationale applied by physicians prescribing statins does not seem to relate to the patients' expectations, whereas factors relating to the patient-physician relationship, the social situation and the perceived control of health seem to affect patient belief. PRACTICE IMPLICATIONS: The association between patients' poor satisfaction of treatment explanation and a low belief in treatment benefits emphasizes the importance of the patient-physician communication. It is suggested that clinical tools are developed in order to identify patients with poor belief in treatment benefit since tailored education for this group might reduce the risk of non-compliance and subsequently reduce the risk of coronary heart disease. |
nfcorpus-qrel-MED-1487 | Generate text that best answers this question: Dr. Dean Ornish | Patients' Expectations of Screening and Preventive Treatments
PURPOSE An informed decision to accept a health care intervention requires an understanding of its likely benefit. This study assessed participants' estimates of the benefit, as well as minimum acceptable benefit, of screening for breast and bowel cancer and medication to prevent hip fracture and cardiovascular disease. METHODS Three general practitioners sent questionnaires to all registered patients aged 50 to 70 years. Patients agreeing to participate in the study were asked to estimate the number of events (fractures or deaths) prevented in a group of 5,000 patients undergoing each intervention over a period of 10 years, and to indicate the minimum number of events avoided by the intervention that they considered justified its use. The proportions of participants that overestimated each intervention's benefit were calculated, and univariate and multivariable analyses of predictors of response were performed. RESULTS The participation rate was 36%: 977 patients were invited to participate in the study, and 354 returned a completed questionnaire. Participants overestimated the degree of benefit conferred by all interventions: 90% of participants overestimated the effect of breast cancer screening, 94% overestimated the effect of bowel cancer screening, 82% overestimated the effect of hip fracture preventive medication, and 69% overestimated the effect of preventive medication for cardiovascular disease. Estimates of minimum acceptable benefit were more conservative, but other than for cardiovascular disease mortality prevention, most respondents indicated a minimum benefit greater than these interventions achieve. A lower level of education was associated with higher estimates of minimum acceptable benefit for all interventions. CONCLUSION Patients overestimated the risk reduction achieved with 4 examples of screening and preventive medications. A lower level of education was associated with higher minimum benefit to justify intervention use. This tendency to overestimate benefits may affect patients' decisions to use such interventions, and practitioners should be aware of this tendency when discussing these interventions with patients. |
nfcorpus-qrel-MED-1488 | Generate text that best answers this question: Dr. Dean Ornish | What benefit do patients expect from adding second and third antihypertensive drugs?
Aims To discover whether patients have the same expectations of benefit from taking the first and any additional drugs for the treatment of hypertension and to investigate any patient characteristics which predict willingness to take treatment. Methods This was an anonymous questionnaire survey carried out in a single primary care group. A random sample of patients from the practice list stratified by age and gender were surveyed to determine what benefit they required before deciding to receive first and subsequent drugs to treat hypertension. They were asked to indicate the largest number needing treatment for 5 years (NNT5) to prevent myocardial infarction in 1 (smallest benefit) that would persuade them of the need for treatment. Demographic information which might explain variability in enthusiasm for treatment was also collected. Results Participants required far higher benefit to consider drug treatment than expected with a mean NNT5 for the first treatment of 15.0 (95% CI 12.3, 17.8). Marginal benefit demanded for the addition of second and third treatments was at least as great with an NNT5 of 13.2 (95% CI 10.8, 15.7) and NNT5 of 11.0 (95% CI 8.6, 13.4). Additional factors influencing willingness to take treatment were gender with a difference in NNT5 between men and women of 7.1 (95% CI 1.7, 12.5), difficulty in making the decision (very easy vs very difficult) of 14.9 (95% CI 6.0, 23.8), and years in full time education 2.0 (95% CI 0.9, 3.0) for each additional year of education. Any slope of NNT5 with increasing number of tablets disappeared when gender, years in education, and difficulty in reaching a decision were taken into account simultaneously. Conclusions People may have greater expectation of benefit from antihypertensive drug treatment than it provides. They certainly do not view the addition of subsequent drugs as any lesser step than starting the first in terms of the benefit expected. Full understanding of both the risks and benefits may be of critical importance with those spending longer in full time education and those expending more effort in making the decision accepting more treatment. The discrepancy between benefit expected and that available demands further research into methods of determining patients’ expectations and informing individual patient decisions. |
nfcorpus-qrel-MED-1490 | Generate text that best answers this question: Dr. Dean Ornish | Are preventive drugs preventive enough? A study of patients' expectation of benefit from preventive drugs.
OBJECTIVES: The study aimed to find the threshold of benefit for a hypothetical cholesterol-lowering drug below which the subject would not be prepared to take the drug. We also looked at whether proximity to the target event (myocardial infarction) and the subjects' views on drug taking affected this threshold. DESIGN: We studied 307 subjects using a written questionnaire and interview. Group 1 (102 subjects) had just been discharged from the coronary care unit. Group 2 (105 subjects) were taking cardio-protective drugs but had no recent history of myocardial infarction. Group 3 (100 subjects) had no history of myocardial infarction and were taking no cardio-protective drugs. RESULTS: Median values for the threshold of benefit below which the subject would not take the preventive drug were 20%, 20%, and 30% absolute risk reduction for Groups 1, 2 and 3 respectively. Median values for expectation of average prolongation of life were 12, 12 and 18 months respectively. Only 27% of subjects would take a drug offering 5% or less absolute risk reduction over five years. Subjects' views on medicinal drug taking in general and proximity to the target event were predictors of the acceptance of preventive drugs. Eighty percent of subjects wished to be told the numerical benefit of a preventive drug before starting on it. CONCLUSION: For the majority, the expectation of benefit from a preventive drug is higher than the actual benefit provided by current drug strategies. There is a tension between the patient's right to know about the chance of benefiting from a preventive drug and the likely reduction in uptake if they are so informed. |
nfcorpus-qrel-MED-1914 | Generate text that best answers this question: Dr. Dean Ornish | Early life stress and telomere length: Investigating the connection and possible mechanisms
How can adverse experiences in early life, such as maltreatment, exert such powerful negative effects on health decades later? The answer may lie in changes to DNA. New research suggests that exposure to stress can accelerate the erosion of DNA segments called telomeres. Shorter telomere length correlates with chronological age and also disease morbidity and mortality. Thus, telomere erosion is a potential mechanism linking childhood stress to health problems later in life. However, an array of mechanistic, methodological, and basic biological questions must be addressed in order to translate telomere discoveries into clinical applications for monitoring health and predicting disease risk. This paper covers the current state of the science and lays out new research directions. |
nfcorpus-qrel-MED-1915 | Generate text that best answers this question: Dr. Dean Ornish | Work-Related Exhaustion and Telomere Length: A Population-Based Study
Background Psychological stress is suggested to accelerate the rate of biological aging. We investigated whether work-related exhaustion, an indicator of prolonged work stress, is associated with accelerated biological aging, as indicated by shorter leukocyte telomeres, that is, the DNA-protein complexes that cap chromosomal ends in cells. Methods We used data from a representative sample of the Finnish working-age population, the Health 2000 Study. Our sample consisted of 2911 men and women aged 30–64. Work-related exhaustion was assessed using the Maslach Burnout Inventory - General Survey. We determined relative leukocyte telomere length using a quantitative real-time polymerase chain reaction (PCR) -based method. Results After adjustment for age and sex, individuals with severe exhaustion had leukocyte telomeres on average 0.043 relative units shorter (standard error of the mean 0.016) than those with no exhaustion (p = 0.009). The association between exhaustion and relative telomere length remained significant after additional adjustment for marital and socioeconomic status, smoking, body mass index, and morbidities (adjusted difference 0.044 relative units, standard error of the mean 0.017, p = 0.008). Conclusions These data suggest that work-related exhaustion is related to the acceleration of the rate of biological aging. This hypothesis awaits confirmation in a prospective study measuring changes in relative telomere length over time. |
nfcorpus-qrel-MED-1916 | Generate text that best answers this question: Dr. Dean Ornish | The association between physical activity in leisure time and leukocyte telomere length.
BACKGROUND: Physical inactivity is an important risk factor for many aging-related diseases. Leukocyte telomere dynamics (telomere length and age-dependent attrition rate) are ostensibly a biological indicator of human aging. We therefore tested the hypothesis that physical activity level in leisure time (over the past 12 months) is associated with leukocyte telomere length (LTL) in normal healthy volunteers. METHODS: We studied 2401 white twin volunteers, comprising 2152 women and 249 men, with questionnaires on physical activity level, smoking status, and socioeconomic status. Leukocyte telomere length was derived from the mean terminal restriction fragment length and adjusted for age and other potential confounders. RESULTS: Leukocyte telomere length was positively associated with increasing physical activity level in leisure time (P< .001); this association remained significant after adjustment for age, sex, body mass index, smoking, socioeconomic status, and physical activity at work. The LTLs of the most active subjects were 200 nucleotides longer than those of the least active subjects (7.1 and 6.9 kilobases, respectively; P= .006). This finding was confirmed in a small group of twin pairs discordant for physical activity level (on average, the LTL of more active twins was 88 nucleotides longer than that of less active twins; P= .03). CONCLUSIONS: A sedentary lifestyle (in addition to smoking, high body mass index, and low socioeconomic status) has an effect on LTL and may accelerate the aging process. This provides a powerful message that could be used by clinicians to promote the potentially antiaging effect of regular exercise. |
nfcorpus-qrel-MED-1917 | Generate text that best answers this question: Dr. Dean Ornish | Effect of healthy lifestyle behaviors on the association between leukocyte telomere length and coronary artery calcium.
The telomere length is an indicator of biologic aging, and shorter telomeres have been associated with coronary artery calcium (CAC), a validated indicator of coronary atherosclerosis. It is unclear, however, whether healthy lifestyle behaviors affect the relation between telomere length and CAC. In a sample of subjects aged 40 to 64 years with no previous diagnosis of coronary heart disease, stroke, diabetes mellitus, or cancer (n = 318), healthy lifestyle behaviors of greater fruit and vegetable consumption, lower meat consumption, exercise, being at a healthy weight, and the presence of social support were examined to determine whether they attenuated the association between a shorter telomere length and the presence of CAC. Logistic regression analyses controlling for age, gender, race/ethnicity, and Framingham risk score revealed that the relation between having shorter telomeres and the presence of CAC was attenuated in the presence of high social support, low meat consumption, and high fruit and vegetable consumption. Those with shorter telomeres and these characteristics were not significantly different from those with longer telomeres. Conversely, the subjects with shorter telomeres and less healthy lifestyles had a significantly increased risk of the presence of CAC: low fruit and vegetable consumption (odds ratio 3.30, 95% confidence interval 1.61 to 6.75), high meat consumption (odds ratio 3.33, 95% confidence interval 1.54 to 7.20), and low social support (odds ratio 2.58, 95% confidence interval 1.24 to 5.37). Stratification by gender yielded similar results for men; however, among women, only fruit and vegetable consumption attenuated the shorter telomere length and CAC relation. In conclusion, the results of the present study suggest that being involved in healthy lifestyle behaviors might attenuate the association between shorter telomere length and coronary atherosclerosis, as identified using CAC. 2010 Elsevier Inc. All rights reserved. |
nfcorpus-qrel-MED-1918 | Generate text that best answers this question: Dr. Dean Ornish | Intensive meditation training, immune cell telomerase activity, and psychological mediators.
BACKGROUND: Telomerase activity is a predictor of long-term cellular viability, which decreases with chronic psychological distress (Epel et al., 2004). Buddhist traditions claim that meditation decreases psychological distress and promotes well-being (e.g., Dalai Lama and Cutler, 2009). Therefore, we investigated the effects of a 3-month meditation retreat on telomerase activity and two major contributors to the experience of stress: Perceived Control (associated with decreased stress) and Neuroticism (associated with increased subjective distress). We used mediation models to test whether changes in Perceived Control and Neuroticism explained meditation retreat effects on telomerase activity. In addition, we investigated whether two qualities developed by meditative practice, increased Mindfulness and Purpose in Life, accounted for retreat-related changes in the two stress-related variables and in telomerase activity. METHODS: Retreat participants (n=30) meditated for ∼6 h daily for 3 months and were compared with a wait-list control group (n=30) matched for age, sex, body mass index, and prior meditation experience. Retreat participants received instruction in concentrative meditation techniques and complementary practices used to cultivate benevolent states of mind (Wallace, 2006). Psychological measures were assessed pre- and post-retreat. Peripheral blood mononuclear cell samples were collected post-retreat for telomerase activity. Because there were clear, a priori hypotheses, 1-tailed significance criteria were used throughout. RESULTS: Telomerase activity was significantly greater in retreat participants than in controls at the end of the retreat (p<0.05). Increases in Perceived Control, decreases in Neuroticism, and increases in both Mindfulness and Purpose in Life were greater in the retreat group (p<0.01). Mediation analyses indicated that the effect of the retreat on telomerase was mediated by increased Perceived Control and decreased Neuroticism. In turn, changes in Perceived Control and Neuroticism were both partially mediated by increased Mindfulness and Purpose in Life. Additionally, increases in Purpose in Life directly mediated the telomerase group difference, whereas increases in Mindfulness did not. CONCLUSIONS: This is the first study to link meditation and positive psychological change with telomerase activity. Although we did not measure baseline telomerase activity, the data suggest that increases in perceived control and decreases in negative affectivity contributed to an increase in telomerase activity, with implications for telomere length and immune cell longevity. Further, Purpose in Life is influenced by meditative practice and directly affects both perceived control and negative emotionality, affecting telomerase activity directly as well as indirectly. Copyright © 2010 Elsevier Ltd. All rights reserved. |
nfcorpus-qrel-MED-1919 | Generate text that best answers this question: Dr. Dean Ornish | Human telomerase model shows the role of the TEN domain in advancing the double helix for the next polymerization step
Telomerases constitute a group of specialized ribonucleoprotein enzymes that remediate chromosomal shrinkage resulting from the “end-replication” problem. Defects in telomere length regulation are associated with several diseases as well as with aging and cancer. Despite significant progress in understanding the roles of telomerase, the complete structure of the human telomerase enzyme bound to telomeric DNA remains elusive, with the detailed molecular mechanism of telomere elongation still unknown. By application of computational methods for distant homology detection, comparative modeling, and molecular docking, guided by available experimental data, we have generated a three-dimensional structural model of a partial telomerase elongation complex composed of three essential protein domains bound to a single-stranded telomeric DNA sequence in the form of a heteroduplex with the template region of the human RNA subunit, TER. This model provides a structural mechanism for the processivity of telomerase and offers new insights into elongation. We conclude that the RNA∶DNA heteroduplex is constrained by the telomerase TEN domain through repeated extension cycles and that the TEN domain controls the process by moving the template ahead one base at a time by translation and rotation of the double helix. The RNA region directly following the template can bind complementarily to the newly synthesized telomeric DNA, while the template itself is reused in the telomerase active site during the next reaction cycle. This first structural model of the human telomerase enzyme provides many details of the molecular mechanism of telomerase and immediately provides an important target for rational drug design. |
nfcorpus-qrel-MED-1920 | Generate text that best answers this question: Dr. Dean Ornish | Look AHEAD (Action for Health in Diabetes): design and methods for a clinical trial of weight loss for the prevention of cardiovascular disease in ...
Overweight and obesity are major contributors to both type 2 diabetes and cardiovascular disease (CVD). Moreover, individuals with type 2 diabetes who are overweight or obese are at particularly high risk for CVD morbidity and mortality. Although short-term weight loss has been shown to ameliorate obesity-related metabolic abnormalities and CVD risk factors, the long-term consequences of intentional weight loss in overweight or obese individuals with type 2 diabetes have not been adequately examined. The primary objective of the Look AHEAD clinical trial is to assess the long-term effects (up to 11.5 years) of an intensive weight loss program delivered over 4 years in overweight and obese individuals with type 2 diabetes. Approximately 5000 male and female participants who have type 2 diabetes, are 45-74 years of age, and have a body mass index >or=25 kg/m(2) will be randomized to one of the two groups. The intensive lifestyle intervention is designed to achieve and maintain weight loss through decreased caloric intake and increased physical activity. This program is compared to a control condition given diabetes support and education. The primary study outcome is time to incidence of a major CVD event. The study is designed to provide a 0.90 probability of detecting an 18% difference in major CVD event rates between the two groups. Other outcomes include components of CVD risk, cost and cost-effectiveness, diabetes control and complications, hospitalizations, intervention processes, and quality of life. |
nfcorpus-qrel-MED-1921 | Generate text that best answers this question: Dr. Dean Ornish | Intake of Small-to-Medium-Chain Saturated Fatty Acids Is Associated with Peripheral Leukocyte Telomere Length in Postmenopausal Women
Dietary factors, including dietary fat, may affect the biological aging process, as reflected by the shortening of telomere length (TL), by affecting levels of oxidative stress and inflammatory responses. We examined the direct relations of total and types of dietary fats and fat-rich foods to peripheral leukocyte TL. In 4029 apparently healthy postmenopausal women who participated in the Women’s Health Initiative, intakes of total fat, individual fatty acids, and fat-rich foods were assessed by a questionnaire. TL was measured by quantitative polymerase chain reaction. Intake of short-to-medium-chain saturated fatty acids (SMSFAs; aliphatic tails of ≤12 carbons) was inversely associated with TL. Compared with participants in other quartiles of SMSFA intake, women who were in the highest quartile (median: 1.29% of energy) had shorter TLs [mean: 4.00 kb (95% CI: 3.89, 4.11 kb)], whereas women in the lowest quartile of intake (median: 0.29% of energy) had longer TLs [mean: 4.13 kb (95% CI: 4.03, 4.24 kb); P-trend = 0.046]. Except for lauric acid, all other individual SMSFAs were inversely associated with TL (P < 0.05). In isoenergetic substitution models, the substitution of 1% of energy from SMSFAs with any other energy source was associated with 119 bp longer TLs (95% CI: 21, 216 bp). Intakes of nonskim milk, butter, and whole-milk cheese (major sources of SMSFAs) were all inversely associated with TL. No significant associations were found with long-chain saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids. In conclusion, we found that higher intakes of SMSFAs and SMSFA-rich foods were associated with shorter peripheral leukocyte TL among postmenopausal women. These findings suggest the potential roles of SMSFAs in the rate of biological aging. |
nfcorpus-qrel-MED-1922 | Generate text that best answers this question: Dr. Dean Ornish | Stress and Telomere Biology: A Lifespan Perspective
In the past decade, the growing field of telomere science has opened exciting new avenues for understanding the cellular and molecular substrates of stress and stress-related aging processes ver the lifespan. Shorter telomere length is associated with advancing chronological age and also increased disease morbidity and mortality. Emerging studies suggest that stress accelerates the erosion of telomeres from very early in life and possibly even influences the initial (newborn) setting of telomere length. In this review, we highlight recent empirical evidence linking stress and mental illnesses at various times across the lifespan with telomere erosion. We first present findings in the developmental programming of telomere biology linking prenatal stress to newborn and adult telomere length. We then present findings linking exposure to childhood trauma and to certain mental disorders with telomere shortening. Last, we review studies that characterize the relationship between related health-risk behaviors with telomere shortening over the lifespan, and how this process may further buffer the negative effects of stress on telomeres. A better understanding of the mechanisms that govern and regulate telomere biology throughout the lifespan may inform our understanding of etiology and the long-term consequences of stress and mental illnesses on aging processes in diverse populations and settings. |
nfcorpus-qrel-MED-1923 | Generate text that best answers this question: Dr. Dean Ornish | Loving-Kindness Meditation practice associated with longer telomeres in women.
Relatively short telomere length may serve as a marker of accelerated aging, and shorter telomeres have been linked to chronic stress. Specific lifestyle behaviors that can mitigate the effects of stress might be associated with longer telomere lengths. Previous research suggests a link between behaviors that focus on the well-being of others, such as volunteering and caregiving, and overall health and longevity. We examined relative telomere length in a group of individuals experienced in Loving-Kindness Meditation (LKM), a practice derived from the Buddhist tradition which utilizes a focus on unselfish kindness and warmth towards all people, and control participants who had done no meditation. Blood was collected by venipuncture, and Genomic DNA was extracted from peripheral blood leukocytes. Quantitative real time PCR was used to measure relative telomere length (RTL) (Cawthon, 2002) in fifteen LKM practitioners and 22 control participants. There were no significant differences in age, gender, race, education, or exposure to trauma, but the control group had a higher mean body mass index (BMI) and lower rates of past depression. The LKM practitioners had longer RTL than controls at the trend level (p=.083); among women, the LKM practitioners had significantly longer RTL than controls, (p=.007), which remained significant even after controlling for BMI and past depression. Although limited by small sample size, these results offer the intriguing possibility that LKM practice, especially in women, might alter RTL, a biomarker associated with longevity. Copyright © 2013 Elsevier Inc. All rights reserved. |
nfcorpus-qrel-MED-1924 | Generate text that best answers this question: Dr. Dean Ornish | Saturated fatty acid metabolism is key link between cell division, cancer, and senescence in cellular and whole organism aging
Cellular senescence is an in vivo and in vitro phenomenon, accompanied by physiological changes including cessation of division and disturbances of organelle structure and function. Review of the literature was undertaken to determine whether there is evidence that whole organism aging and cell senescence share a common initiation pathway. In vivo aged cells of different lineages, including aged T lymphocytes, show high expression of the INK4A-p16 gene. In cell culture when telomeres are shortened past a key length or state, the Arf/Ink gene system (p16/p14 humans, p16/p19 mice) switches on and activates p53, which suppresses further cell division. The p53 gene is a key tumor suppressor and its deletion or mutation allows cancerous growth. The switching on of p53 also causes changes in fatty acid metabolism, especially down-regulation of both fatty acid synthase and stearoyl-CoA (delta-9) desaturase. The co-suppression of these genes together with enhanced uptake of extracellular fatty acids, leads to raised levels of cellular palmitate and induction of either apoptosis or senescence. In senescent cells, the fatty acid composition of the cellular membranes alters and leads to changes in both structure and function of organelles, especially mitochondria. Animal models of accelerated aging exhibit repression of stearoyl-CoA desaturase activity while anti-aging calorie restriction stimulates the same enzyme system. It is concluded that aging in cells and whole organisms share a common initiation pathway and that cellular senescence is protective against cancer. Healthy longevity is likely to be most enhanced by factors that actively suppress excessive cell division. |
nfcorpus-qrel-MED-4877 | Generate text that best answers this question: Dr. Dean Ornish | Increased telomerase activity and comprehensive lifestyle changes: a pilot study.
BACKGROUND: Telomeres are protective DNA-protein complexes at the end of linear chromosomes that promote chromosomal stability. Telomere shortness in human beings is emerging as a prognostic marker of disease risk, progression, and premature mortality in many types of cancer, including breast, prostate, colorectal, bladder, head and neck, lung, and renal cell. Telomere shortening is counteracted by the cellular enzyme telomerase. Lifestyle factors known to promote cancer and cardiovascular disease might also adversely affect telomerase function. However, previous studies have not addressed whether improvements in nutrition and lifestyle are associated with increases in telomerase activity. We aimed to assess whether 3 months of intensive lifestyle changes increased telomerase activity in peripheral blood mononuclear cells (PBMC). METHODS: 30 men with biopsy-diagnosed low-risk prostate cancer were asked to make comprehensive lifestyle changes. The primary endpoint was telomerase enzymatic activity per viable cell, measured at baseline and after 3 months. 24 patients had sufficient PBMCs needed for longitudinal analysis. This study is registered on the ClinicalTrials.gov website, number NCT00739791. FINDINGS: PBMC telomerase activity expressed as natural logarithms increased from 2.00 (SD 0.44) to 2.22 (SD 0.49; p=0.031). Raw values of telomerase increased from 8.05 (SD 3.50) standard arbitrary units to 10.38 (SD 6.01) standard arbitrary units. The increases in telomerase activity were significantly associated with decreases in low-density lipoprotein (LDL) cholesterol (r=-0.36, p=0.041) and decreases in psychological distress (r=-0.35, p=0.047). INTERPRETATION: Comprehensive lifestyle changes significantly increase telomerase activity and consequently telomere maintenance capacity in human immune-system cells. Given this finding and the pilot nature of this study, we report these increases in telomerase activity as a significant association rather than inferring causation. Larger randomised controlled trials are warranted to confirm the findings of this study. |
nfcorpus-qrel-MED-1926 | Generate text that best answers this question: Dr. Dean Ornish | Habitual physical exercise has beneficial effects on telomere length in postmenopausal women.
OBJECTIVE: It has been reported that women benefit from the maintenance of telomere length by estrogen. Exercise may favorably influence telomere length, although results are inconsistent regarding the duration and type of exercise and the cell type used to measure telomere length. The purpose of this study was to investigate the relationship between habitual physical exercise and telomere length in peripheral blood mononuclear cells (PBMCs) in postmenopausal women. Postmenopausal women were chosen as study participants because they are typically estrogen deficient. METHODS: This experimental-control, cross-sectional study included 44 healthy, nondiabetic, nonsmoking, postmenopausal women. Habitual exercisers and sedentary participants were matched for age and body mass index. Body weight, height, blood pressure, and waist and hip circumference were measured. Mitochondrial DNA copy number and telomere length in PBMCs were determined, and biochemical tests were performed. Habitual physical exercise was defined as combined aerobic and resistance exercise performed for at least 60 minutes per session more than three times a week for more than 12 months. RESULTS: The mean age of all participants was 58.11 ± 6.84 years, and participants in the habitual exercise group had been exercising more than three times per week for an average of 19.23 ± 5.15 months. Serum triglyceride levels (P = 0.01), fasting insulin concentrations (P < 0.01), and homeostasis model assessment of insulin resistance (P < 0.01) were significantly lower and high-density lipoprotein cholesterol levels (P < 0.01), circulating adiponectin (P < 0.01), mitochondrial DNA copy number (P < 0.01), and telomere length (P < 0.01) were significantly higher in the habitual exercise group than in the sedentary group. In a stepwise multiple regression analysis, habitual exercise (β = 0.522, P < 0.01) and adiponectin levels (β = 0.139, P = 0.03) were the independent factors associated with the telomere length of PBMCs in postmenopausal women. CONCLUSIONS: Habitual physical exercise is associated with greater telomere length in postmenopausal women. This finding suggests that habitual physical exercise in postmenopausal women may reduce telomere attrition. |
nfcorpus-qrel-MED-4878 | Generate text that best answers this question: Dr. Dean Ornish | Dietary patterns, food groups, and telomere length in the Multi-Ethnic Study of Atherosclerosis (MESA)
Background Telomere length reflects biological aging and may be influenced by environmental factors, including those that affect inflammatory processes. Objective With data from 840 white, black, and Hispanic adults from the Multi-Ethnic Study of Atherosclerosis, we studied cross-sectional associations between telomere length and dietary patterns and foods and beverages that were associated with markers of inflammation. Design Leukocyte telomere length was measured by quantitative polymerase chain reaction. Length was calculated as the amount of telomeric DNA (T) divided by the amount of a single-copy control DNA (S) (T/S ratio). Intake of whole grains, fruit and vegetables, low-fat dairy, nuts or seeds, nonfried fish, coffee, refined grains, fried foods, red meat, processed meat, and sugar-sweetened soda were computed with responses to a 120-item food-frequency questionnaire completed at baseline. Scores on 2 previously defined empirical dietary patterns were also computed for each participant. Results After adjustment for age, other demographics, lifestyle factors, and intakes of other foods or beverages, only processed meat intake was associated with telomere length. For every 1 serving/d greater intake of processed meat, the T/S ratio was 0.07 smaller (β ± SE: −0.07 ± 0.03, P = 0.006). Categorical analysis showed that participants consuming ≥1 serving of processed meat each week had 0.017 smaller T/S ratios than did nonconsumers. Other foods or beverages and the 2 dietary patterns were not associated with telomere length. Conclusions Processed meat intake showed an expected inverse association with telomere length, but other diet features did not show their expected associations. |
nfcorpus-qrel-MED-1928 | Generate text that best answers this question: Dr. Dean Ornish | Telomeres, lifestyle, cancer, and aging
Purpose of review There has been growing evidence that lifestyle factors may affect the health and lifespan of an individual by affecting telomere length. The purpose of this review was to highlight the importance of telomeres in human health and aging and to summarize possible lifestyle factors that may affect health and longevity by altering the rate of telomere shortening. Recent findings Recent studies indicate that telomere length, which can be affected by various lifestyle factors, can affect the pace of aging and onset of age-associated diseases. Summary Telomere length shortens with age. Progressive shortening of telomeres leads to senescence, apoptosis, or oncogenic transformation of somatic cells, affecting the health and lifespan of an individual. Shorter telomeres have been associated with increased incidence of diseases and poor survival. The rate of telomere shortening can be either increased or decreased by specific lifestyle factors. Better choice of diet and activities has great potential to reduce the rate of telomere shortening or at least prevent excessive telomere attrition, leading to delayed onset of age-associated diseases and increased lifespan. This review highlights the role of telomeres in aging and describes the lifestyle factors which may affect telomeres, human health, and aging. |
nfcorpus-qrel-MED-1929 | Generate text that best answers this question: Dr. Dean Ornish | A pilot study of yogic meditation for family dementia caregivers with depressive symptoms: Effects on mental health, cognition, and telomerase activity
BACKGROUND This study examined the effects of brief daily yogic meditation on mental health, cognitive functioning, and immune cell telomerase activity in family dementia caregivers with mild depressive symptoms. METHODS Thirty-nine family dementia caregivers (mean age 60.3 years old (SD=10.2)) were randomized to practicing Kirtan Kriya or listening to relaxation music for 12 minutes per day for eight weeks. The severity of depressive symptoms, mental and cognitive functioning were assessed at baseline and follow-up. Telomerase activity in peripheral blood mononuclear cells (PMBC) was examined in peripheral PBMC pre- and post-intervention. RESULTS The meditation group showed significantly lower levels of depressive symptoms and greater improvement in mental health and cognitive functioning compared to the relaxation group. In the meditation group, 65.2% showed 50% improvement on the Hamilton Depression Rating scale and 52% of the participants showed 50% improvement on the Mental Health Composite Summary score (MCS) of the SF-36 scale; compared to 31.2% and 19% respectively in the relaxation group (pp<0.05). The meditation group showed 43% improvement in telomerase activity compared to 3.7% in the relaxation group (p=0.05). CONCLUSION This pilot study found that brief daily meditation practices by family dementia caregivers can lead to improved mental and cognitive functioning, and lower levels of depressive symptoms. This improvement is accompanied by an increase in telomerase activity suggesting improvement in stress-induced cellular aging. These results need to be confirmed in a larger sample. |
nfcorpus-qrel-MED-1930 | Generate text that best answers this question: Dr. Dean Ornish | Leukocyte telomere length and its relation to food and nutrient intake in an elderly population.
BACKGROUND/OBJECTIVES: Shorter leukocyte telomere length (LTL) is associated with several chronic diseases, but only a few studies have assessed the association between dietary factors and LTL. Our objective was to study the association between fats, fruits, vegetables and LTL in a cross-sectional study design. We hypothesized that intakes of fruits and vegetables would be positively associated with LTL and that intakes of fats, and especially saturated fatty acids (SFAs), would be negatively associated with LTL. SUBJECTS/METHODS: LTL was measured by quantitative real-time polymerase chain reaction in 1942 men and women aged 57-70 years from the Helsinki Birth Cohort Study. We assessed the whole diet by a validated semiquantitative 128-item food-frequency questionnaire. RESULTS: In general, there were only a few significant results. However, total fat and SFA intake (P=0.04 and 0.01, respectively) were inversely associated with LTL in men adjusting for age and energy intake. In women, vegetable intake was positively associated with LTL (P=0.05). Men consuming the most butter and least fruits had significantly shorter telomeres than those consuming the lowest amounts of butter and highest amounts of fruits (P=0.05). We found no association between LTL and body mass index, waist-hip ratio, smoking, physical activity or educational attainment. CONCLUSIONS: In this cross-sectional study of elderly men and women, there were only a few statistically significant effects of diet, but in general they support the hypothesis that fat and vegetable intakes were associated with LTL. |
nfcorpus-qrel-MED-1931 | Generate text that best answers this question: Dr. Dean Ornish | Accelerated Telomere Erosion Is Associated with a Declining Immune Function of Caregivers of Alzheimer’s Disease Patients
Caregivers of Alzheimer’s disease patients endure chronic stress associated with a decline of immune function. To assess the psychological and immunological changes of caregivers, we compared depressive symptoms, PBMC composition, in vitro activation-induced proliferation and cytokine production, and telomere length and telomerase activity of 82 individuals (41 caregivers and 41 age- and gender-matched controls). We found depressive symptoms were significantly higher in caregivers than in controls (p < 0.001). Correspondingly, caregivers had significantly lower T cell proliferation but higher production of immune-regulatory cytokines (TNF-α and IL-10) than controls in response to stimulation in vitro. We examined the impact of these changes on cellular replicative lifespan and found that caregivers had significantly shorter telomere lengths in PBMC than controls (6.2 and 6.4 kb, respectively, p < 0.05) with similar shortening in isolated T cells and monocytes and that this telomere attrition in caregivers was not due to an increase of shorter telomere possessing T cell subsets in PBMC. Finally, we showed that basal telomerase activity in PBMC and T cells was significantly higher in caregivers than in controls (p < 0.0001), pointing to an unsuccessful attempt of cells to compensate the excessive loss of telomeres in caregivers. These findings demonstrate that chronic stress is associated with altered T cell function and accelerated immune cell aging as suggested by excessive telomere loss. |
nfcorpus-qrel-MED-1932 | Generate text that best answers this question: Dr. Dean Ornish | Exposure to violence during childhood is associated with telomere erosion from 5 to 10 years of age: a longitudinal study
There is increasing interest in discovering mechanisms that mediate the effects of childhood stress on late-life disease morbidity and mortality. Previous studies have suggested one potential mechanism linking stress to cellular aging, disease and mortality in humans: telomere erosion. We examined telomere erosion in relation to children’s exposure to violence, a salient early-life stressor, which has known long-term consequences for well-being and is a major public-health and social-welfare problem. In the first prospective-longitudinal study with repeated telomere measurements in children while they experienced stress, we tested the hypothesis that childhood violence exposure would accelerate telomere erosion from age 5 to age 10 years. Violence was assessed as exposure to maternal domestic violence, frequent bullying victimization and physical maltreatment by an adult. Participants were 236 children (49% females; 42% with one or more violence exposures) recruited from the Environmental-Risk Longitudinal Twin Study, a nationally representative 1994–1995 birth cohort. Each child’s mean relative telomere length was measured simultaneously in baseline and follow-up DNA samples, using the quantitative PCR method for T/S ratio (the ratio of telomere repeat copy numbers to single-copy gene numbers). Compared with their counterparts, the children who experienced two or more kinds of violence exposure showed significantly more telomere erosion between age-5 baseline and age-10 follow-up measurements, even after adjusting for sex, socioeconomic status and body mass index (B = −0.052, s.e. = 0.021, P = 0.015). This finding provides support for a mechanism linking cumulative childhood stress to telomere maintenance, observed already at a young age, with potential impact for life-long health. |
nfcorpus-qrel-MED-1933 | Generate text that best answers this question: Dr. Dean Ornish | From the Cover: Accelerated telomere shortening in response to life stress
Numerous studies demonstrate links between chronic stress and indices of poor health, including risk factors for cardiovascular disease and poorer immune function. Nevertheless, the exact mechanisms of how stress gets “under the skin” remain elusive. We investigated the hypothesis that stress impacts health by modulating the rate of cellular aging. Here we provide evidence that psychological stress— both perceived stress and chronicity of stress—is significantly associated with higher oxidative stress, lower telomerase activity, and shorter telomere length, which are known determinants of cell senescence and longevity, in peripheral blood mononuclear cells from healthy premenopausal women. Women with the highest levels of perceived stress have telomeres shorter on average by the equivalent of at least one decade of additional aging compared to low stress women. These findings have implications for understanding how, at the cellular level, stress may promote earlier onset of age-related diseases. |
nfcorpus-qrel-MED-1934 | Generate text that best answers this question: Dr. Dean Ornish | Independent and Combined Effects of Dietary Weight Loss and Exercise on Leukocyte Telomere Length in Postmenopausal Women
Objective Investigate the effects of 12 months of dietary weight loss and/or aerobic exercise on leukocyte telomere length in postmenopausal women. Design and Methods 439 overweight or obese women (50–75 y) were randomized to: i) dietary weight loss (N=118); ii) aerobic exercise (N=117), iii) diet + exercise (N=117), or iv) control (N=87). The diet intervention was a group-based program with a 10% weight loss goal. The exercise intervention was 45 mins/day, 5 days/week of moderate-to-vigorous aerobic activity. Fasting blood samples were taken at baseline and 12 months. DNA was extracted from isolated leukocytes and telomere length was measured by quantitative-polymerase chain reaction (qPCR). Mean changes were compared between groups (intent-to-treat) using generalized estimating equations. Results Baseline telomere length was inversely associated with age (r=−0.12 p<0.01) and positively associated with maximal oxygen uptake (r=0.11, p=0.03), but not with BMI or %body fat. Change in telomere length was inversely correlated with baseline telomere length (r=−0.47, p<0.0001). No significant difference in leukocyte telomere length was detected in any intervention group compared to controls, nor was the magnitude of weight loss associated with telomere length at 12 months. Conclusions Twelve-months of dietary weight loss and exercise did not change telomere length in postmenopausal women. |
nfcorpus-qrel-MED-1935 | Generate text that best answers this question: Dr. Dean Ornish | Diet-related telomere shortening and chromosome stability
Recent evidences have highlighted an influence of micronutrients in the maintenance of telomere length (TL). In order to explore whether diet-related telomere shortening had any physiological relevance and was accompanied by significant damage in the genome, in the present study, TL was assessed by terminal restriction fragment (TRF) analysis in peripheral blood lymphocytes of 56 healthy subjects for which detailed information on dietary habits was available and data were compared \with the incidence of nucleoplasmic bridges (NPBs), a marker of chromosomal instability related to telomere dysfunction visualised with the cytokinesis-blocked micronucleus assay. To increase the capability to detect even slight impairment of telomere function, the incidence of NPBs was also evaluated on cells exposed in vitro to ionising radiation. Care was taken to control for potential confounding factors that might influence TL, viz. age, hTERT genotype and smoking status. Data showed that higher consumption of vegetables was related with significantly higher mean TL (P = 0.013); in particular, the analysis of the association between micronutrients and mean TL highlighted a significant role of antioxidant intake, especially beta-carotene, on telomere maintenance (P = 0.004). However, the diet-related telomere shortening did not result in associated increased spontaneous or radiation-induced NPBs. The distribution of TRFs was also analysed and a slight prevalence of radiation-induced NPBs (P = 0.03) was observed in subjects with higher amount of very short TRFs (<2 kb). The relative incidence of very short TRFs was positively associate with ageing (P = 0.008) but unrelated to vegetables consumption and daily intake of micronutrients, suggesting that the degree of telomere erosion related with low dietary intake of antioxidants observed in this study was not so extensive to lead to chromosome instability. |
nfcorpus-qrel-MED-1936 | Generate text that best answers this question: Dr. Dean Ornish | Physical exercise prevents cellular senescence in circulating leukocytes and in the vessel wall.
BACKGROUND: The underlying molecular mechanisms of the vasculoprotective effects of physical exercise are incompletely understood. Telomere erosion is a central component of aging, and telomere-associated proteins regulate cellular senescence and survival. This study examines the effects of exercising on vascular telomere biology and endothelial apoptosis in mice and the effects of long-term endurance training on telomere biology in humans. METHODS AND RESULTS: C57/Bl6 mice were randomized to voluntary running or no running wheel conditions for 3 weeks. Exercise upregulated telomerase activity in the thoracic aorta and in circulating mononuclear cells compared with sedentary controls, increased vascular expression of telomere repeat-binding factor 2 and Ku70, and reduced the expression of vascular apoptosis regulators such as cell-cycle-checkpoint kinase 2, p16, and p53. Mice preconditioned by voluntary running exhibited a marked reduction in lipopolysaccharide-induced aortic endothelial apoptosis. Transgenic mouse studies showed that endothelial nitric oxide synthase and telomerase reverse transcriptase synergize to confer endothelial stress resistance after physical activity. To test the significance of these data in humans, telomere biology in circulating leukocytes of young and middle-aged track and field athletes was analyzed. Peripheral blood leukocytes isolated from endurance athletes showed increased telomerase activity, expression of telomere-stabilizing proteins, and downregulation of cell-cycle inhibitors compared with untrained individuals. Long-term endurance training was associated with reduced leukocyte telomere erosion compared with untrained controls. CONCLUSIONS: Physical activity regulates telomere-stabilizing proteins in mice and in humans and thereby protects from stress-induced vascular apoptosis. |
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