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nfcorpus-corpus-MED-3197 | null | Beef in an Optimal Lean Diet study: effects on lipids, lipoproteins, and apolipoproteins
Background: A Step I diet with lean beef compared with lean white meat both decrease LDL cholesterol. To our knowledge, no studies have evaluated a low–saturated fatty acid (SFA) (<7% calories) diet that contains lean beef. Objective: We studied the effect on LDL cholesterol of cholesterol-lowering diets with varying amounts of lean beef [ie, Dietary Approaches to Stop Hypertension (DASH): 28 g beef/d; Beef in an Optimal Lean Diet (BOLD): 113 g beef/d; and Beef in an Optimal Lean Diet plus additional protein (BOLD+): 153 g beef/d] compared with that of a healthy American diet (HAD). Design: Thirty-six hypercholesterolemic participants (with LDL-cholesterol concentrations >2.8 mmol/L) were randomly assigned to consume each of the 4 diets (HAD: 33% total fat, 12% SFA, 17% protein, and 20 g beef/d), DASH (27% total fat, 6% SFA, 18% protein, and 28 g beef/d), BOLD (28% total fat, 6% SFA, 19% protein, and 113 g beef/d), and BOLD+ (28% total fat, 6% SFA, 27% protein, and 153 g beef/d) for 5 wk. Results: There was a decrease in total cholesterol (TC) and LDL-cholesterol concentrations (P < 0.05) after consumption of the DASH (−0.49 ± 0.11 and −0.37 ± 0.09 mmol/L, respectively), BOLD (−0.48 ± 0.10 and −0.35 ± 0.9 mmol/L, respectively), and BOLD+ (−0.50 ± 0.10 and −0.345 ± 0.09 mmol/L, respectively) diets compared with after consumption of the HAD (−0.22 ± 0.10 and −0.14 ± 0.10 mmol/L, respectively). Apolipoprotein A-I, C-III, and C-III bound to apolipoprotein A1 particles decreased after BOLD and BOLD+ diets compared with after the HAD, and there was a greater decrease in apolipoprotein B after consumption of the BOLD+ diet than after consumption of the HAD (P < 0.05 for both). LDL cholesterol and TC decreased after consumption of the DASH, BOLD, and BOLD+ diets when the baseline C-reactive protein (CRP) concentration was <1 mg/L; LDL cholesterol and TC decreased when baseline CRP concentration was >1 mg/L with the BOLD and BOLD+ diets. Conclusions: Low-SFA, heart-healthy dietary patterns that contain lean beef elicit favorable effects on cardiovascular disease (CVD) lipid and lipoprotein risk factors that are comparable to those elicited by a DASH dietary pattern. These results, in conjunction with the beneficial effects on apolipoprotein CVD risk factors after consumption of the BOLD and BOLD+ diets, which were greater with the BOLD+ diet, provide support for including lean beef in a heart-healthy dietary pattern. This trial was registered at clinicaltrials.gov as NCT00937898. |
nfcorpus-queries-PLAIN-2580 | null | Academy of Nutrition and Dietetics Conflicts of Interest |
nfcorpus-corpus-MED-3198 | null | Cheese intake in large amounts lowers LDL-cholesterol concentrations compared with butter intake of equal fat content.
BACKGROUND: Despite its high content of saturated fatty acids, cheese does not seem to increase plasma total and LDL-cholesterol concentrations when compared with an equivalent intake of fat from butter. This effect may be due to the high calcium content of cheese, which results in a higher excretion of fecal fat. OBJECTIVES: The objective was to compare the effects of diets of equal fat content rich in either hard cheese or butter or a habitual diet on blood pressure and fasting serum blood lipids, C-reactive protein, glucose, and insulin. We also examined whether fecal fat excretion differs with the consumption of cheese or butter. DESIGN: The study was a randomized dietary intervention consisting of two 6-wk crossover periods and a 14-d run-in period during which the subjects consumed their habitual diet. The study included 49 men and women who replaced part of their habitual dietary fat intake with 13% of energy from cheese or butter. RESULTS: After 6 wk, the cheese intervention resulted in lower serum total, LDL-, and HDL-cholesterol concentrations and higher glucose concentrations than did the butter intervention. Cheese intake did not increase serum total or LDL-cholesterol concentrations compared with the run-in period, during which total fat and saturated fat intakes were lower. Fecal fat excretion did not differ between the cheese and butter periods. CONCLUSION: Cheese lowers LDL cholesterol when compared with butter intake of equal fat content and does not increase LDL cholesterol compared with a habitual diet. This trial is registered at clinicaltrials.gov as NCT01140165. |
nfcorpus-queries-PLAIN-2580 | null | Academy of Nutrition and Dietetics Conflicts of Interest |
nfcorpus-corpus-MED-4602 | null | Manufactured uncertainty: protecting public health in the age of contested science and product defense.
The strategy of "manufacturing uncertainty" has been used with great success by polluters and manufacturers of dangerous products to oppose public health and environmental regulation. This strategy entails questioning the validity of scientific evidence on which the regulation is based. While this approach is most identified with the tobacco industry, it has been used by producers of asbestos, benzene, beryllium, chromium, diesel exhaust, lead, plastics, and other hazardous products to avoid environmental and occupational health regulation. It is also central to the debate on global warming. The approach is now so common that it is unusual for the science not to be challenged by an industry facing regulation. Manufacturing uncertainty has become a business in itself; numerous technical consulting firms provide a service often called "product defense" or "litigation support." As these names imply, the usual objective of these activities is not to generate knowledge to protect public health but to protect a corporation whose products are alleged to have toxic properties. Evidence in the scientific literature of the funding effect--the close correlation between the results of a study desired by a study's funder and the reported results of that study--suggests that the financial interest of a study's sponsors should be taken into account when considering the study's findings. Similarly, the interpretation of data by scientists with financial conflicts should be seen in this light. Manufacturing uncertainty is antithetical to the public health principle that decisions be made using the best evidence currently available. |
nfcorpus-queries-PLAIN-2580 | null | Academy of Nutrition and Dietetics Conflicts of Interest |
nfcorpus-corpus-MED-2288 | null | Current protein intake in America: analysis of the National Health and Nutrition Examination Survey, 2003-2004.
In recent years there has been considerable interest in the benefits of high-protein diets. This study determined current usual intake of protein in America. Using the most recent data from the National Health and Nutrition Examination Survey, 2003-2004, usual protein intake for Americans aged 2+ years was estimated. Usual protein intake was calculated on a grams per day, grams per kilogram ideal body weight, and a percentage of calories basis. Protein intake averaged 56 +/- 14 g/d in young children, increased to a high of approximately 91 +/- 22 g/d in adults aged 19-30 y, and decreased to approximately 66 +/- 17 g/d in the elderly. The percentage of the male population who consumed less than the estimated average requirement was very low. Our estimates indicated that 7.7% of adolescent females and 7.2-8.6% of older adult women reported consuming protein levels below their estimated average requirement. The median intake of protein on a percentage of calories basis ranged from 13.4% in children aged 4-8 y to 16.0% in men aged 51-70 y. Even the 95th percentile of protein intake did not approach the highest acceptable macronutrient distribution range of 35% for an age/sex group. The highest 95th percentile of protein intake was 20.8% of calories in men aged 51-70 y. Given the demonstrated benefits of higher protein intake on weight management, sarcopenia, and other physiologic functions, efforts should be undertaken to ensure that Americans consume the recommended amount of protein (17-21% of calories as expected from MyPyramid food patterns). |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3137 | null | Americans Do Not Meet Federal Dietary Recommendations
A longstanding goal of dietary surveillance has been to estimate the proportion of the population with intakes above or below a target, such as a recommended level of intake. However, until now, statistical methods for assessing the alignment of food intakes with recommendations have been lacking. The purposes of this study were to demonstrate the National Cancer Institute’s method of estimating the distribution of usual intake of foods and determine the proportion of the U.S. population who does not meet federal dietary recommendations. Data were obtained from the 2001–2004 NHANES for 16,338 persons, aged 2 y and older. Quantities of foods reported on 24-h recalls were translated into amounts of various food groups using the MyPyramid Equivalents Database. Usual dietary intake distributions were modeled, accounting for sequence effect, weekend/weekday effect, sex, age, poverty income ratio, and race/ethnicity. The majority of the population did not meet recommendations for all of the nutrient-rich food groups, except total grains and meat and beans. Concomitantly, overconsumption of energy from solid fats, added sugars, and alcoholic beverages (“empty calories”) was ubiquitous. Over 80% of persons age ≥71 y and over 90% of all other sex-age groups had intakes of empty calories that exceeded the discretionary calorie allowances. In conclusion, nearly the entire U.S. population consumes a diet that is not on par with recommendations. These findings add another piece to the rather disturbing picture that is emerging of a nation’s diet in crisis. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2290 | null | Nutrient Profiles of Vegetarian and Non Vegetarian Dietary Patterns
Background Differences in nutrient profiles between vegetarian and non vegetarian dietary patterns reflect nutritional differences that may contribute to the development of disease. Objective To compare nutrient intakes between dietary patterns characterized by consumption or exclusion of meat and dairy products. Design Cross-sectional study of 71751 subjects (mean age 59 years) from the Adventist-Health-Study-2. Data was collected between 2002 and 2007. Participants completed a 204-item validated semi-quantitative food frequency questionnaire. Dietary patterns compared were: non vegetarian, semi vegetarian, pesco vegetarian, lacto-ovo vegetarian and strict vegetarian. ANCOVA was used to analyze differences in nutrient intakes by dietary patterns and were adjusted for age, and sex and race. BMI and other relevant demographic data were reported and compared by dietary pattern using chi-square tests and ANOVA. Results Many nutrient intakes varied significantly between dietary patterns. Non vegetarians had the lowest intakes of plant proteins, fiber, β-Carotene, and Mg than those following vegetarian dietary patterns and the highest intakes of saturated, trans, arachidonic, and docosahexaenoic fatty acids. The lower tails of some nutrient distributions in strict vegetarians suggested inadequate intakes by a portion of the subjects. Energy intake was similar among dietary patterns at close to 2000 kcal/d with the exception of semi vegetarians that had an intake of 1713 kcal/d. Mean BMI was highest in non-vegetarians (mean; standard deviation [SD]) (28.7; [6.4]) and lowest in strict vegetarians (24.0; [4.8]). Conclusions Nutrient profiles varied markedly between dietary patterns that were defined by meat and dairy intakes. These differences can be of interest in the etiology of obesity and chronic diseases. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2291 | null | Viscous versus nonviscous soluble fiber supplements: mechanisms and evidence for fiber-specific health benefits.
PURPOSE: This review focuses on the health benefits of viscous versus nonviscous soluble fibers, why symptoms can occur with increased fiber consumption, and how to avoid symptoms to improve adherence with a high-fiber diet. DATA SOURCES: Review of scientific literature as well as evidence-based guidelines and resources. CONCLUSIONS: While it is generally known that "fiber is good for you," it is less well known that specific health benefits are associated with specific fiber characteristics. Many of the health benefits of fiber can be directly correlated with the viscosity of soluble fibers when hydrated (i.e., gel-forming). A reduction in viscosity of a given fiber will attenuate these health benefits, and a nonviscous fiber does not exhibit these health benefits. IMPLICATIONS FOR PRACTICE: Increasing the viscosity of chyme with a viscous soluble fiber has been shown clinically to lower cholesterol for cardiovascular health, improve glycemic control in type 2 diabetes, normalize stool form in both constipation (softens hard stool) and diarrhea (firms loose/liquid stool), and improve the objective clinical measures of metabolic syndrome (glycemic control, lipoprotein profile, body mass index/weight loss, and blood pressure). ©2012 The Author(s) Journal compilation ©2012 American Academy of Nurse Practitioners. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2292 | null | Diverticular disease: eat your fiber!
In industrialized nations, diverticular disease affects up to 70% of individuals by 60 years of age, with symptoms that can range from mild gastrointestinal disturbance to incapacitating pain. Diverticular disease appears to be related to increasing affluence and changed diet: Current theory holds that diverticular disease's origin is low-fiber diet. This explains why its incidence is highest and accelerating in the more prosperous countries where intake of fiber has decreased and intake of milled grains and refined sugars has increased over time. Not all patients develop symptoms, but if they do, the most frequent complaints associated with diverticulosis are cramping in the left-lower quadrant, bloating, constipation, and soiling. If diverticula perforate the gut's wall into the pericolic tissue, small and large abscesses, accompanied by bleeding, can form. Fistulization, when it occurs, most often penetrates to the bladder. Treatment addresses symptoms and may require hospitalization. During symptomatic periods, patients do best on low-fiber, bland diets. Once the acute episode or highly symptomatic period resolves or chronic disease is managed, patients should gradually increase dietary fiber to 20 to 30 grams daily or take dietary fiber in the form of bulk stimulants like psyllium. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2293 | null | Dietary Fiber Future Directions: Integrating New Definitions and Findings to Inform Nutrition Research and Communication
The CODEX Alimentarius definition of dietary fiber includes all nondigestible carbohydrate polymers with a degree of polymerization of 3 or more as dietary fiber with the proviso that they show health benefits. The global definition, if accepted by all authoritative bodies, offers a chance for international harmonization in research, food composition tables, and food labeling. Its nonacceptance highlights problems that may develop when definitions vary by region. The definition requires that the research community agrees upon physiological effects for which there is substantial scientific agreement, e.g., fibers’ effects on laxation and gut health, on attenuating blood lipids and blood glucose and insulin, and in promoting fermentation in the large bowel. The definition also necessitates the delineation of research protocols to prove the benefits of various isolated and synthesized fibers. These should emanate from evidence-based reviews that fairly weigh epidemiological data while considering that added fibers are not reflected in many food composition databases. They then should include well-controlled, randomized, control trials and utilize animal studies to determine mechanisms. Agreement on many study variables such as the type of subject and the type of baseline diet that best fits the question under investigation will also be needed. Finally, the definition establishes that all types of fiber can address the severe fiber consumption gap that exists throughout the world by recognizing that the combination of fiber-rich and -fortified foods increases fiber intake while allowing consumers to stay within allowed energy levels. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2294 | null | Comparison of Nutritional Quality of the Vegan, Vegetarian, Semi-Vegetarian, Pesco-Vegetarian and Omnivorous Diet
The number of studies comparing nutritional quality of restrictive diets is limited. Data on vegan subjects are especially lacking. It was the aim of the present study to compare the quality and the contributing components of vegan, vegetarian, semi-vegetarian, pesco-vegetarian and omnivorous diets. Dietary intake was estimated using a cross-sectional online survey with a 52-items food frequency questionnaire (FFQ). Healthy Eating Index 2010 (HEI-2010) and the Mediterranean Diet Score (MDS) were calculated as indicators for diet quality. After analysis of the diet questionnaire and the FFQ, 1475 participants were classified as vegans (n = 104), vegetarians (n = 573), semi-vegetarians (n = 498), pesco-vegetarians (n = 145), and omnivores (n = 155). The most restricted diet, i.e., the vegan diet, had the lowest total energy intake, better fat intake profile, lowest protein and highest dietary fiber intake in contrast to the omnivorous diet. Calcium intake was lowest for the vegans and below national dietary recommendations. The vegan diet received the highest index values and the omnivorous the lowest for HEI-2010 and MDS. Typical aspects of a vegan diet (high fruit and vegetable intake, low sodium intake, and low intake of saturated fat) contributed substantially to the total score, independent of the indexing system used. The score for the more prudent diets (vegetarians, semi-vegetarians and pesco-vegetarians) differed as a function of the used indexing system but they were mostly better in terms of nutrient quality than the omnivores. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2295 | null | Trends in dietary fiber intake in the United States, 1999-2008.
BACKGROUND: Intake of dietary fiber has been recommended for many years as part of the guidelines from the American Heart Association, the Institute of Medicine, and other groups. The recommended Adequate Intake for dietary fiber for adults is 25 to 38 g/day (14 g/1,000 kcal/day). OBJECTIVE: To determine the average daily intake of dietary fiber among adults during the past decade and, specifically, to document progress toward national goals. DESIGN: Cross-sectional weighted data from the National Health and Nutrition Examination Survey among adults aged 18 years and older. PARTICIPANTS/SETTING: Data were collected from noninstitutionalized adults aged 18 years and older using a nationally representative, complex, multistage, probability-based survey of people living in the United States that was conducted by the National Center for Health Statistics. MAIN OUTCOME MEASURES: Daily dietary fiber intake by members of the US population based on 2-year groupings of the continuous survey from 1999 to 2008. RESULTS: Mean daily dietary fiber intake for 1999-2000 was 15.6 g/day, for 2001-2002 intake was 16.1g/day, for 2003-2004 intake was 15.5 g/day, for 2005-2006 intake was 15.8 g/day, and for 2007-2008 intake was 15.9 g/day. Participants with obesity (body mass index ≥30) consistently reported lower fiber intake than did individuals with normal weight or overweight (14.6 to 15.4 g/day and 15.6 to 16.8 g/day, respectively; P<0.0001). Mexican Americans had significantly higher intake in 1999-2000 than non-Hispanic whites (18.0 vs 16.1g/day; P<0.05), but Mexican Americans' intake did not increase over time (17.7 g/day in 2007-2008). Non-Hispanic blacks had fiber intake of 12.5 g/day at baseline that increased modestly to 13.1 g/day by 2007-2008. CONCLUSIONS: Daily fiber intake generally has not progressed toward national goals during the past decade, but there are some differences according to health and social factors. Additional clinical practice and public health strategies are needed. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2296 | null | Vegan lifestyle behaviors: an exploration of congruence with health-related beliefs and assessed health indices.
This study aimed to investigate health belief as a major motive for diet and lifestyle behaviors of 100 vegans in the United States; and to determine congruence with selected health and nutrition outcomes. Response data from an administered questionnaire was analyzed. Statistical analyses determined the most common factors influencing diet choice; the number of vegans practicing particular lifestyle behaviors; body mass index; and prevalence of self-reported chronic disease diagnoses. Nutrient intakes were analyzed and assessed against Dietary Reference Intakes. Health was the most reported reason for diet choice (47%). In the health belief, animal welfare, and religious/other motive categories, low percentages of chronic disease diagnoses were reported: 27%, 11%, and 15%, respectively. There were no significant differences in health behaviors and indices among vegan motive categories, except for product fat content choices. Within the entire study population, health-related vegan motive coincided with regular exercise; 71% normal BMI (mean=22.6); minimal alcohol and smoking practices; frequently consumed vegetables, nuts, and grains; healthy choices in meal types, cooking methods, and low-fat product consumption; and adequate intakes for most protective nutrients when compared to reference values. But incongruence was found with 0% intake adequacy for vitamin D; and observation of excessive sodium use. Copyright © 2013 Elsevier Ltd. All rights reserved. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2498 | null | Dietary Restriction, Growth Factors and Aging: from yeast to humans
Dietary restriction (DR) and reduced growth factor signaling both elevate resistance to oxidative stress, reduce macromolecular damage, and increase lifespan in model organisms. In rodents, both DR and decreased growth factor signaling reduce the incidence of tumors and slow down cognitive decline and aging. DR reduces cancer and cardiovascular disease and mortality in monkeys, and reduces metabolic traits associated with diabetes, cardiovascular disease and cancer in humans. Neoplasias and diabetes are also rare in humans with loss of function mutations in the growth hormone receptor. DR and reduced growth factor signaling may thus slow aging by similar, evolutionarily conserved, mechanisms. We review these conserved anti-aging pathways in model organisms, discuss their link to disease prevention in mammals, and consider the negative side effects that might hinder interventions intended to extend healthy lifespan in humans. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2517 | null | mTOR is a key modulator of ageing and age-related disease
Many experts in the biology of ageing believe that pharmacological interventions to slow ageing are a matter of ‘when’ rather than ‘if’. A leading target for such interventions is the nutrient response pathway defined by the mechanistic target of rapamycin (mTOR). Inhibition of this pathway extends lifespan in model organisms and confers protection against a growing list of age-related pathologies. Characterized inhibitors of this pathway are already clinically approved, and others are under development. Although adverse side effects currently preclude use in otherwise healthy individuals, drugs that target the mTOR pathway could one day become widely used to slow ageing and reduce age-related pathologies in humans. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2519 | null | Caloric restriction in humans: potential pitfalls and health concerns.
To date, the only intervention that has consistently been shown to slow the rate of aging, and to increase mean and maximum lifespan in short-lived species, is life-long calorie restriction. It is yet unclear whether long-term calorie restriction in longer lived species (i.e. primates and humans) will have a similar effect. In humans, several studies investigating short-term calorie restriction or "weight loss" programs suggest beneficial outcomes on parameters of cardiovascular disease. Studies on long-term calorie restriction are performed on a self-selected group of human subjects and show similar effects. However, few studies are currently investigating the quality of life and potential pitfalls of long-term calorie restriction in humans. It is likely that some of the physiological and psychological effects of caloric restriction that occur in animals may impact the human life very differently. For certain, calorie restriction has a plethora of health benefits in mammals, such as a reduction in age-related diseases such as cancer. However, despite the "magic" of CR, this intervention in humans may present itself with a number of health concerns, which may not be applicable to or impact the life of experimental animals, but may do so in humans. These potential pitfalls and "side effects" are not clearly addressed in the literature and will be a focus of this review. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2501 | null | Amino acid sensing and regulation of mTORC1.
Amino acids play fundamental roles in the cell both as the building blocks of new proteins and as metabolic precursors. To adapt to their limitation during periods of protein starvation, multiple adaptive mechanisms have evolved, including a rapid cessation of new protein synthesis, an increase in amino acid biosynthesis and transport, and autophagy. Here, we discuss what we currently know about how amino acid limitation is sensed, and how this sensing might be transmitted to mTORC1 to regulate protein synthesis and autophagy. Copyright © 2012 Elsevier Ltd. All rights reserved. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2502 | null | Macronutrient balance and lifespan
Dietary restriction (DR) without malnutrition is widely regarded to be a universal mechanism for prolonging lifespan. It is generally believed that the benefits of DR arise from eating fewer calories (termed caloric restriction, CR). Here we argue that, rather than calories, the key determinant of the relationship between diet and longevity is the balance of protein to non-protein energy ingested. This ratio affects not only lifespan, but also total energy intake, metabolism, immunity and the likelihood of developing obesity and associated metabolic disorders. Among various possible mechanisms linking macronutrient balance to lifespan, the nexus between the TOR and AMPK signaling pathways is emerging as a central coordinator. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2513 | null | Insights into the beneficial effect of caloric/ dietary restriction for a healthy and prolonged life
Over the last several years, new evidence has kept pouring in about the remarkable effect of caloric restriction (CR) on the conspicuous bedfellows- aging and cancer. Through the use of various animal models, it is now well established that by reducing calorie intake one can not only increase life span but, also, lower the risk of various age related diseases such as cancer. Cancer cells are believed to be more dependent on glycolysis for their energy requirements than normal cells and, therefore, can be easily targeted by alteration in the energy-metabolic pathways, a hallmark of CR. Apart from inhibiting the growth of transplantable tumors, CR has been also shown to inhibit the development of spontaneous, radiation, and chemically induced tumors. The question regarding the potentiality of the anti-tumor effect of CR in humans has been in part answered by the resistance of a cohort of women, who had suffered from anorexia in their early life, to breast cancer. However, human research on the beneficial effect of CR is still at an early stage and needs further validation. Though the complete mechanism of the anti-tumor effect of CR is far from clear, the plausible involvement of nutrient sensing pathways or IGF-1 pathways proposed for its anti-aging action cannot be overruled. In fact, cancer cell lines, mutant for proteins involved in IGF-1 pathways, failed to respond to CR. In addition, CR decreases the levels of many growth factors, anabolic hormones, inflammatory cytokines, and oxidative markers that are deregulated in several cancers. In this review, we discuss the anti-tumor effect of CR, describing experiments done in vitro in tumor models and in vivo in mouse models in which the tumor was induced by means of radiation or chemical exposure, expressing oncogenes or deleting tumor suppression genes. We also discuss the proposed mechanisms of CR anti-tumor action. Lastly, we argue the necessity of gene expression studies in cancerous versus normal cells upon CR. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2504 | null | Nutrient control of TORC1, a cell-cycle regulator.
It is well established that the target of rapamycin (TOR) protein kinase has pivotal roles in controlling cell functions (including protein synthesis, cell growth and cell proliferation) and is implicated in numerous human diseases. Mammalian TOR complex 1 (mTORC1) signalling is activated by hormones and growth factors, and is also stimulated by intracellular amino acids. Recent research has provided important new insight into the poorly understood mechanism by which amino acids activate mTORC1 signalling, showing that the protein kinase MAP4K3 and Rag GTPases have important roles in this. mTORC1 is known to control the G1/S transition of the cell cycle: new data show that (m)TORC1 also controls G2/M progression in yeast and mammals, albeit in contrasting ways. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2505 | null | Ten years of life: Is it a matter of choice?
BACKGROUND: Relative risk estimates suggest that effective implementation of behaviors commonly advocated in preventive medicine should increase life expectancy, although there is little direct evidence. OBJECTIVE: To test the hypothesis that choices regarding diet, exercise, and smoking influence life expectancy. METHODS: A total of 34 192 California Seventh-Day Adventists (75% of those eligible) were enrolled in a cohort and followed up from 1976 to 1988. A mailed questionnaire provided dietary and other exposure information at study baseline. Mortality for all subjects was ascertained by matching to state death tapes and the National Death Index. RESULTS: California Adventists have higher life expectancies at the age of 30 years than other white Californians by 7.28 years (95% confidence interval, 6.59-7.97 years) in men and by 4.42 years (95% confidence interval, 3.96-4.88 years) in women, giving them perhaps the highest life expectancy of any formally described population. Commonly observed combinations of diet, exercise, body mass index, past smoking habits, and hormone replacement therapy (in women) can account for differences of up to 10 years of life expectancy among Adventists. A comparison of life expectancy when these factors take high-risk compared with low-risk values shows independent effects that vary between 1.06 and 2.74 years for different variables. The effect of each variable is assessed with all others at either medium- or high-risk levels. CONCLUSIONS: Choices regarding diet, exercise, cigarette smoking, body weight, and hormone replacement therapy, in combination, appear to change life expectancy by many years. The longevity experience of Adventists probably demonstrates the beneficial effects of more optimal behaviors. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2506 | null | Caloric restriction, the traditional Okinawan diet, and healthy aging: the diet of the world's longest-lived people and its potential impact on mor...
Long-term caloric restriction (CR) is a robust means of reducing age-related diseases and extending life span in multiple species, but the effects in humans are unknown. The low caloric intake, long life expectancy, and the high prevalence of centenarians in Okinawa have been used as an argument to support the CR hypothesis in humans. However, no long-term, epidemiologic analysis has been conducted on traditional dietary patterns, energy balance, and potential CR phenotypes for the specific cohort of Okinawans who are purported to have had a calorically restricted diet. Nor has this cohort's subsequent mortality experience been rigorously studied. Therefore, we investigated six decades of archived population data on the elderly cohort of Okinawans (aged 65-plus) for evidence of CR. Analyses included traditional diet composition, energy intake, energy expenditure, anthropometry, plasma DHEA, mortality from age-related diseases, and current survival patterns. Findings include low caloric intake and negative energy balance at younger ages, little weight gain with age, life-long low BMI, relatively high plasma DHEA levels at older ages, low risk for mortality from age-related diseases, and survival patterns consistent with extended mean and maximum life span. This study lends epidemiologic support for phenotypic benefits of CR in humans and is consistent with the well-known literature on animals with regard to CR phenotypes and healthy aging. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2507 | null | mTORC1 activity as a determinant of cancer risk--rationalizing the cancer-preventive effects of adiponectin, metformin, rapamycin, and low-protein ...
Increased plasma levels of adiponectin, metformin therapy of diabetes, rapamycin administration in transplant patients, and lifelong consumption of low-protein plant-based diets have all been linked to decreased risk for various cancers. These benefits may be mediated, at least in part, by down-regulated activity of the mTORC1 complex, a key regulator of protein translation. By boosting the effective availability of the translation initiator eIF4E, mTORC1 activity promotes the translation of a number of "weak" mRNAs that code for proteins, often up-regulated in cancer, that promote cellular proliferation, invasiveness, and angiogenesis, and that abet cancer promotion and chemoresistance by opposing apoptosis. Measures which inhibit eIF4E activity, either directly or indirectly, may have utility not only for cancer prevention, but also for the treatment of many cancers in which eIF4E drives malignancy. Since eIF4E is overexpressed in many cancers, strategies which target eIF4E directly--some of which are now being assessed clinically--may have the broadest efficacy in this regard. Many of the "weak" mRNAs coding for proteins that promote malignant behavior or chemoresistance are regulated transcriptionally by NF-kappaB and/or Stat3, which are active in a high proportion of cancers; thus, regimens concurrently targeting eIF4E, NF-kappaB, and Stat3 may suppress these proteins at both the transcriptional and translational levels, potentially achieving a very marked reduction in their expression. Copyright © 2011 Elsevier Ltd. All rights reserved. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-5239 | null | Leucine signaling in the pathogenesis of type 2 diabetes and obesity
Epidemiological evidence points to increased dairy and meat consumption, staples of the Western diet, as major risk factors for the development of type 2 diabetes (T2D). This paper presents a new concept and comprehensive review of leucine-mediated cell signaling explaining the pathogenesis of T2D and obesity by leucine-induced over-stimulation of mammalian target of rapamycin complex 1 (mTORC1). mTORC1, a pivotal nutrient-sensitive kinase, promotes growth and cell proliferation in response to glucose, energy, growth factors and amino acids. Dairy proteins and meat stimulate insulin/insulin-like growth factor 1 signaling and provide high amounts of leucine, a primary and independent stimulator for mTORC1 activation. The downstream target of mTORC1, the kinase S6K1, induces insulin resistance by phosphorylation of insulin receptor substrate-1, thereby increasing the metabolic burden of β-cells. Moreover, leucine-mediated mTORC1-S6K1-signaling plays an important role in adipogenesis, thus increasing the risk of obesity-mediated insulin resistance. High consumption of leucine-rich proteins explains exaggerated mTORC1-dependent insulin secretion, increased β-cell growth and β-cell proliferation promoting an early onset of replicative β-cell senescence with subsequent β-cell apoptosis. Disturbances of β-cell mass regulation with increased β-cell proliferation and apoptosis as well as insulin resistance are hallmarks of T2D, which are all associated with hyperactivation of mTORC1. In contrast, the anti-diabetic drug metformin antagonizes leucine-mediated mTORC1 signaling. Plant-derived polyphenols and flavonoids are identified as natural inhibitors of mTORC1 and exert anti-diabetic and anti-obesity effects. Furthermore, bariatric surgery in obesity reduces increased plasma levels of leucine and other branched-chain amino acids. Attenuation of leucine-mediated mTORC1 signaling by defining appropriate upper limits of the daily intake of leucine-rich animal and dairy proteins may offer a great chance for the prevention of T2D and obesity, as well as other epidemic diseases of civilization with increased mTORC1 signaling, especially cancer and neurodegenerative diseases, which are frequently associated with T2D. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2509 | null | Amino acid sensing in dietary-restriction-mediated longevity: roles of signal-transducing kinases GCN2 and TOR
DR (dietary restriction), or reduced food intake without malnutrition, is associated with extended longevity, improved metabolic fitness and increased stress resistance in a wide range of organisms. DR is often referred to as calorie restriction, implying that reduced energy intake is responsible for its widespread and evolutionarily conserved benefits. However, recent data indicate dietary amino acid restriction as a key mediator of DR benefits. In fruitflies, an imbalance in essential amino acid intake is thought to underlie longevity benefits of DR. In mammals, reduced dietary protein or essential amino acid intake can extend longevity, improve metabolic fitness and increase stress resistance. In the present paper we review two evolutionarily conserved signal transduction pathways responsible for sensing amino acid levels. The eIF2α (eukaryotic initiation factor 2α) kinase GCN2 (general amino acid control non-derepressible 2) senses the absence of one or more amino acids by virtue of direct binding to uncharged cognate tRNAs. The presence of certain amino acids, such as leucine, permits activation of the master growth regulating kinase TOR (target of rapamycin). These two signal transduction pathways react to amino acid deprivation by inhibiting general protein translation while at the same time increasing translation of specific mRNAs involved in restoring homoeostasis. Together, these pathways may contribute to the regulation of longevity, metabolic fitness and stress resistance. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2510 | null | Comparative and meta-analytic insights into life extension via dietary restriction.
Dietary restriction (DR) extends the lifespan of a wide range of species, although the universality of this effect has never been quantitatively examined. Here, we report the first comprehensive comparative meta-analysis of DR across studies and species. Overall, DR significantly increased lifespan, but this effect is modulated by several factors. In general, DR has less effect in extending lifespan in males and also in non-model organisms. Surprisingly, the proportion of protein intake was more important for life extension via DR than the degree of caloric restriction. Furthermore, we show that reduction in both age-dependent and age-independent mortality rates drives life extension by DR among the well-studied laboratory model species (yeast, nematode worms, fruit flies and rodents). Our results suggest that convergent adaptation to laboratory conditions better explains the observed DR-longevity relationship than evolutionary conservation although alternative explanations are possible. © 2012 The Authors. Aging Cell © 2012 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2511 | null | The Okinawan diet: health implications of a low-calorie, nutrient-dense, antioxidant-rich dietary pattern low in glycemic load.
Residents of Okinawa, the southernmost prefecture of Japan, are known for their long average life expectancy, high numbers of centenarians, and accompanying low risk of age-associated diseases. Much of the longevity advantage in Okinawa is thought to be related to a healthy lifestyle, particularly the traditional diet, which is low in calories yet nutritionally dense, especially with regard to phytonutrients in the form of antioxidants and flavonoids. Research suggests that diets associated with a reduced risk of chronic diseases are similar to the traditional Okinawan diet, that is, vegetable and fruit heavy (therefore phytonutrient and antioxidant rich) but reduced in meat, refined grains, saturated fat, sugar, salt, and full-fat dairy products. Many of the characteristics of the diet in Okinawa are shared with other healthy dietary patterns, such as the traditional Mediterranean diet or the modern DASH (Dietary Approaches to Stop Hypertension) diet. Features such as the low levels of saturated fat, high antioxidant intake, and low glycemic load in these diets are likely contributing to a decreased risk for cardiovascular disease, some cancers, and other chronic diseases through multiple mechanisms, including reduced oxidative stress. A comparison of the nutrient profiles of the three dietary patterns shows that the traditional Okinawan diet is the lowest in fat intake, particularly in terms of saturated fat, and highest in carbohydrate intake, in keeping with the very high intake of antioxidant-rich yet calorie-poor orange-yellow root vegetables, such as sweet potatoes, and green leafy vegetables. Deeper analyses of the individual components of the Okinawan diet reveal that many of the traditional foods, herbs, or spices consumed on a regular basis could be labeled "functional foods" and, indeed, are currently being explored for their potential health-enhancing properties. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2512 | null | Extending healthy ageing: nutrient sensitive pathway and centenarian population
Ageing is a challenge for any living organism and human longevity is a complex phenotype. With increasing life expectancy, maintaining long-term health, functionality and well-being during ageing has become an essential goal. To increase our understanding of how ageing works, it may be advantageous to analyze the phenotype of centenarians, perhaps one of the best examples of successful ageing. Healthy ageing involves the interaction between genes, the environment, and lifestyle factors, particularly diet. Besides evaluating specific gene-environment interactions in relation to exceptional longevity, it is important to focus attention on modifiable lifestyle factors such as diet and nutrition to achieve extension of health span. Furthermore, a better understanding of human longevity may assist in the design of strategies to extend the duration of optimal human health. In this article we briefly discuss relevant topics on ageing and longevity with particular focus on dietary patterns of centenarians and nutrient-sensing pathways that have a pivotal role in the regulation of life span. Finally, we also discuss the potential role of Nrf2 system in the pro-ageing signaling emphasizing its phytohormetic activation. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3000 | null | Red meat consumption and cancer: reasons to suspect involvement of bovine infectious factors in colorectal cancer.
An increased risk for colorectal cancer has been consistently reported for long-time consumption of cooked and processed red meat. This has frequently been attributed to chemical carcinogens arising during the cooking process of meat. Long-time fish or poultry consumption apparently does not increase the risk, although similar or higher concentrations of chemical carcinogens were recorded in their preparation for consumption. The geographic epidemiology of colorectal cancer seems to correspond to regions with a high rate of beef consumption. Countries with a virtual absence of beef in the diet (India) or where preferably lamb or goat meat is consumed (several Arabic countries) reveal low rates of colorectal cancer. In China, pork consumption has a long tradition, with an intermediate colorectal cancer rate. In Japan and Korea, large scale beef and pork imports started after World War II or after the Korean War. A steep rise in colorectal cancer incidence was noted after 1970 in Japan and 1990 in Korea. The consumption of undercooked beef (e.g., shabu-shabu, Korean yukhoe and Japanese yukke) became very popular in both countries. The available data are compatible with the interpretation that a specific beef factor, suspected to be one or more thermoresistant potentially oncogenic bovine viruses (e.g., polyoma-, papilloma- or possibly single-stranded DNA viruses) may contaminate beef preparations and lead to latent infections in the colorectal tract. Preceding, concomitant or subsequent exposure to chemical carcinogens arising during cooking procedures should result in increased risk for colorectal cancer synergistic with these infections. Copyright © 2011 UICC. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2765 | null | The value of current nutrition information.
To prevent or delay the occurrence of chronic diseases, scientific bodies from the cardiologic and oncologic disciplines have made recommendations regarding the daily dietary intake of certain macro- and micronutrients. This study assessed the knowledge of a random population of 2,305 individuals comprising members of the public, health care workers, university graduate students, and health club attendees. Segments of this population might be expected to have a greater understanding and ability to implement these dietary recommendations. We found that over 90% of the participants were unaware of the recommendations for calcium, salt, vitamin A, and fiber, and the fiber content in a high fiber cereal. Approximately 80% of the participants were unaware of the recommendations regarding fat intake and could not calculate the fat content of a food product. Almost half of the study population took a vitamin pill daily. Of the subjects who were aware of the correct unit measurement for vitamin A (IU), almost 25% of gave a response that exceeded the recommended daily intake. A majority of this study population were unaware of the dietary recommendations regarding the prevention of cardiovascular events and cancer. Subgroups of this study population that might be expected to have more information regarding these recommendations (i.e., having higher education or being a health care professional) did not display a satisfactory level of knowledge. To further compound the problems of adhering to the recommended guidelines, the labeling of many food products is misleading. The recommendations on dietary intake and the information on food product content must be transmitted to the public in a form that allows for ready application when purchasing and consuming food. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2997 | null | The Etiological Significance of Related Diseases
If disease patterns emerge which show that certain diseases can be related, this is a valuable pointer to a common cause. This article traces the principle of interpreting disease relationships, illustrated by several common conditions of western civilization, for which the common cause is postulated as being removal of fiber from the diet. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3001 | null | Towards a new system of health: the challenge of Western disease.
Over the last three decades, the concept of Western disease has become well established. Medicine has approached this group of diseases by searching for new cures but has achieved relatively little success. We argue that medicine should now accept the failure of this strategy and place a major emphasis on prevention. The key objective is to change the climate of opinion so that prevention is taken seriously by the general population. The chief activity should be a wide ranging public education campaign so as to persuade people to live a healthier lifestyle. Medicine will require restructuring in order to carry out this work. Medical education needs to be reformed so that medical students receive the necessary training. This must be done as part of an integrated approach in which government, industry and medical research all play a major role. Governments should use taxation and subsidies in areas such as food and tobacco so as to shift consumption patterns towards healthier products. Governments must also tighten laws on tobacco sales and advertising, support health education, and improve food labelling. Industry must be made far more responsive to the health needs of the population. This should be done both by public education, so as to alter demand, and by government action. Medical research should change its emphasis from studying the detailed mechanisms of disease ("complex research") to studying the role of lifestyle factors ("simple research"). |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-2999 | null | Western diseases and their emergence related to diet.
Many of the commonest diseases in the economically more developed communities are characteristic of modern Western culture. Evidence is presented suggesting that they represent a failure of adaptation to the dramatic changes in diet that have been associated with the emergence of modern Western culture. Dietary changes aimed at the alleviation and prevention of these diseases are discussed and recommended. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-4313 | null | A vegetarian dietary pattern as a nutrient-dense approach to weight management: an analysis of the national health and nutrition examination survey...
BACKGROUND: Population-based studies have shown that vegetarians have lower body mass index than nonvegetarians, suggesting that vegetarian diet plans may be an approach for weight management. However, a perception exists that vegetarian diets are deficient in certain nutrients. OBJECTIVE: To compare dietary quality of vegetarians, nonvegetarians, and dieters, and to test the hypothesis that a vegetarian diet would not compromise nutrient intake when used to manage body weight. DESIGN: Cross-sectional analysis of National Health and Nutrition Examination Survey (1999-2004) dietary and anthropometric data. Diet quality was determined using United States Department of Agriculture's Healthy Eating Index 2005. Participants included adults aged 19 years and older, excluding pregnant and lactating women (N = 13,292). Lacto-ovo vegetarian diets were portrayed by intakes of participants who did not eat meat, poultry, or fish on the day of the survey (n = 851). Weight-loss diets were portrayed by intakes of participants who consumed 500 kcal less than their estimated energy requirements (n = 4,635). Mean nutrient intakes and body mass indexes were adjusted for energy, sex, and ethnicity. Using analysis of variance, all vegetarians were compared to all nonvegetarians, dieting vegetarians to dieting nonvegetarians, and nondieting vegetarians to nondieting nonvegetarians. RESULTS: Mean intakes of fiber, vitamins A, C, and E, thiamin, riboflavin, folate, calcium, magnesium, and iron were higher for all vegetarians than for all nonvegetarians. Although vegetarian intakes of vitamin E, vitamin A, and magnesium exceeded that of nonvegetarians (8.3 ± 0.3 vs 7.0 ± 0.1 mg; 718 ± 28 vs 603 ± 10 μg; 322 ± 5 vs 281 ± 2 mg), both groups had intakes that were less than desired. The Healthy Eating Index score did not differ for all vegetarians compared to all nonvegetarians (50.5 ± 0.88 vs 50.1 ± 0.33, P = 0.6). CONCLUSIONS: These findings suggest that vegetarian diets are nutrient dense, consistent with dietary guidelines, and could be recommended for weight management without compromising diet quality. Copyright © 2011 American Dietetic Association. Published by Elsevier Inc. All rights reserved. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3148 | null | Sympathetic nervous system activity and resting metabolic rate in vegetarians.
We examined the resting metabolic rate (RMR) and sympathetic nervous system activity of young male vegetarians (n = 17) and nonvegetarians (n = 40). Subjects were characterized for RMR by indirect calorimetry, norepinephrine kinetics from infusions of tritiated norepinephrine, energy and macronutrient intake from a 3-day food diary, and body composition by underwater weighing. Vegetarians reported a greater relative intake of carbohydrates (62% +/- 5% v 51% +/- 6%, P < .01) and a lower relative intake of fat (25% +/- 5% v 33% +/- 6%, P < .01) than nonvegetarians, whereas no differences were observed in daily energy intake, body composition, or maximal aerobic capacity (VO2max) between groups. Vegetarians exhibited an 11% higher absolute RMR (1.29 +/- 0.15 v 1.16 +/- 0.13 kcal/min, P < .01), a higher plasma concentration of norepinephrine (216 +/- 33 v 165 +/- 18 pg/mL, P < .01), and a greater norepinephrine appearance rate (0.50 +/- 0.08 v 0.36 +/- 0.09 micrograms/min, P < .01) than nonvegetarians. After statistically controlling for differences in relative amounts of carbohydrate and fat in the diet and for norepinephrine concentrations, no significant differences in adjusted RMR between vegetarians and nonvegetarians were noted. These results suggest that the higher RMR observed in young male vegetarians is partially mediated by differences in dietary macronutrient composition and increased sympathetic nervous system activity. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3149 | null | Four therapeutic diets: adherence and acceptability.
Many health conditions are treated, at least in part, by therapeutic diets. Although the success of any intervention depends on its acceptability to the patient, the acceptability of therapeutic diets and factors that influence it have been largely neglected in nutrition research. A working definition of acceptability is proposed and an examination and summary are provided of available data on the acceptability of common diet regimens used for medical conditions. The goal is to suggest ways to improve the success of therapeutic diets. The proposed working definition of "acceptability" refers to the user's judgment of the advantages and disadvantages of a therapeutic diet-in relation to palatability, costs, and effects on eating behaviour and health-that influence the likelihood of adherence. Very low-calorie, reduced-fat omnivorous, vegetarian and vegan, and low-carbohydrate diets all achieve acceptability among the majority of users in studies of up to one year, in terms of attrition and adherence rates and results of questionnaires assessing eating behaviours. Longer studies are fewer, but they suggest that vegetarian, vegan, and reduced-fat diets are acceptable, as indicated by sustained changes in nutrient intake. Few studies of this length have been published for very low-calorie or low-carbohydrate diets. Long-term studies of adherence and acceptability of these and other therapeutic diets are warranted. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3242 | null | 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-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3243 | null | A dietary intervention for recurrent prostate cancer after definitive primary treatment: results of a randomized pilot trial.
OBJECTIVES: Considerable evidence has shown that diet can affect both the incidence and the progression of prostate cancer. The objective of this study was to determine whether men in this situation could make a change to a diet emphasizing plant-based foods and fish and to examine the effect on quality of life (QOL) and prostate-specific antigen (PSA) velocity. METHODS: A total of 36 men and their partners were randomly assigned to attend a series of 11 dietary and cooking classes that also integrated mindfulness practice as a support in making the change or a wait-list control group. Assessments were made of dietary intake, QOL, and PSA at baseline, after intervention (11 weeks), and 3 months after intervention. RESULTS: The intervention group showed significant reductions in the consumption of saturated fat and increased consumption of vegetable proteins with accompanying reductions in animal proteins, including dairy products. They also showed increased QOL. Although no significant change was found in the rate of PSA increase between the two groups, the mean PSA doubling time for the intervention group was substantially longer at the 3-month follow-up visit than that of the controls. CONCLUSIONS: Men with a increasing PSA level after primary treatment were able to make a change to a prostate-healthy diet, accompanied by increases in QOL. No significant difference was found in the log PSA slope between the two groups; however, the PSA doubling time increased substantially in the intervention group compared with that in the controls. Future trials should examine the effect of the prostate-healthy diet with a larger sample of men for a longer period. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3244 | null | 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-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3245 | null | 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-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3270 | null | Protein methionine content and MDA-lysine adducts are inversely related to maximum life span in the heart of mammals.
Aging affects all organisms and its basic mechanisms are expected to be conserved across species. Oxidation of proteins has been proposed to be one of the basic mechanisms linking oxygen radicals with the basic aging process. If oxidative damage to proteins is involved in aging, long-lived animals (which age slowly) should show lower levels of markers of this kind of damage than short-lived ones. However, this possibility has not been investigated yet. In this study, steady-state levels of markers of different kinds of protein damage--oxidation (glutamic and aminoadipic semialdehydes), mixed glyco- and lipoxidation (carboxymethyl- and carboxyethyllysine), lipoxidation (malondialdehydelysine) and amino acid composition--were measured in the heart of eight mammalian species ranging in maximum life span (MLSP) from 3.5 to 46 years. Oxidation markers were directly correlated with MLSP across species. Mixed glyco- and lipoxidation markers did not correlate with MLSP. However, the lipoxidation marker malondialdehydelysine was inversely correlated with MLSP (r2=0.85; P<0.001). The amino acid compositional analysis revealed that methionine is the only amino acid strongly correlated MLSP and that such correlation is negative (r2=0.93; P<0.001). This trait may contribute to lower steady-state levels of oxidized methionine residues in cellular proteins. These results reinforce the notion that high longevity in homeothermic vertebrates is achieved in part by constitutively decreasing the sensitivity of both tissue proteins and lipids to oxidative damage. This is obtained by modifying the constituent structural components of proteins and lipids, selecting those less sensitive to oxidative modifications. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3271 | null | Can dietary methionine restriction increase the effectiveness of chemotherapy in treatment of advanced cancer?
Most metastatic tumors, such as those originating in the prostate, lung, and gastrointestinal tract, respond poorly to conventional chemotherapy. Novel treatment strategies for advanced cancer are therefore desperately needed. Dietary restriction of the essential amino acid methionine offers promise as such a strategy, either alone or in combination with chemotherapy or other treatments. Numerous in vitro and animal studies demonstrate the effectiveness of dietary methionine restriction in inhibiting growth and eventually causing death of cancer cells. In contrast, normal host tissues are relatively resistant to methionine restriction. These preclinical observations led to a phase I clinical trial of dietary methionine restriction for adults with advanced cancer. Preliminary findings from this trial indicate that dietary methionine restriction is safe and feasible for the treatment of patients with advanced cancer. In addition, the trial has yielded some preliminary evidence of antitumor activity. One patient with hormone-independent prostate cancer experienced a 25% reduction in serum prostate-specific antigen (PSA) after 12 weeks on the diet, and a second patient with renal cell cancer experienced an objective radiographic response. The possibility that methionine restriction may act synergistically with other cancer treatments such as chemotherapy is being explored. Findings to date support further investigation of dietary methionine restriction as a novel treatment strategy for advanced cancer. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3272 | null | Colorectal cancer screening with odour material by canine scent detection
Objective Early detection and early treatment are of vital importance to the successful treatment of various cancers. The development of a novel screening method that is as economical and non-invasive as the faecal occult blood test (FOBT) for early detection of colorectal cancer (CRC) is needed. A study was undertaken using canine scent detection to determine whether odour material can become an effective tool in CRC screening. Design Exhaled breath and watery stool samples were obtained from patients with CRC and from healthy controls prior to colonoscopy. Each test group consisted of one sample from a patient with CRC and four control samples from volunteers without cancer. These five samples were randomly and separately placed into five boxes. A Labrador retriever specially trained in scent detection of cancer and a handler cooperated in the tests. The dog first smelled a standard breath sample from a patient with CRC, then smelled each sample station and sat down in front of the station in which a cancer scent was detected. Results 33 and 37 groups of breath and watery stool samples, respectively, were tested. Among patients with CRC and controls, the sensitivity of canine scent detection of breath samples compared with conventional diagnosis by colonoscopy was 0.91 and the specificity was 0.99. The sensitivity of canine scent detection of stool samples was 0.97 and the specificity was 0.99. The accuracy of canine scent detection was high even for early cancer. Canine scent detection was not confounded by current smoking, benign colorectal disease or inflammatory disease. Conclusions This study shows that a specific cancer scent does indeed exist and that cancer-specific chemical compounds may be circulating throughout the body. These odour materials may become effective tools in CRC screening. In the future, studies designed to identify cancer-specific volatile organic compounds will be important for the development of new methods for early detection of CRC. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3273 | null | The low-methionine content of vegan diets may make methionine restriction feasible as a life extension strategy.
Recent studies confirm that dietary methionine restriction increases both mean and maximal lifespan in rats and mice, achieving "aging retardant" effects very similar to those of caloric restriction, including a suppression of mitochondrial superoxide generation. Although voluntary caloric restriction is never likely to gain much popularity as a pro-longevity strategy for humans, it may be more feasible to achieve moderate methionine restriction, in light of the fact that vegan diets tend to be relatively low in this amino acid. Plant proteins - especially those derived from legumes or nuts - tend to be lower in methionine than animal proteins. Furthermore, the total protein content of vegan diets, as a function of calorie content, tends to be lower than that of omnivore diets, and plant protein has somewhat lower bioavailability than animal protein. Whole-food vegan diets that moderate bean and soy intake, while including ample amounts of fruit and wine or beer, can be quite low in methionine, while supplying abundant nutrition for health (assuming concurrent B12 supplementation). Furthermore, low-fat vegan diets, coupled with exercise training, can be expected to promote longevity by decreasing systemic levels of insulin and free IGF-I; the latter effect would be amplified by methionine restriction - though it is not clear whether IGF-I down-regulation is the sole basis for the impact of low-methionine diets on longevity in rodents. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3274 | null | Olfactory detection of human bladder cancer by dogs: proof of principle study
Objective To determine whether dogs can be trained to identify people with bladder cancer on the basis of urine odour more successfully than would be expected by chance alone. Design Experimental, “proof of principle” study in which six dogs were trained to discriminate between urine from patients with bladder cancer and urine from diseased and healthy controls and then evaluated in tests requiring the selection of one bladder cancer urine sample from six controls. Participants 36 male and female patients (age range 48-90 years) presenting with new or recurrent transitional cell carcinoma of the bladder (27 samples used for training; 9 used for formal testing); 108 male and female controls (diseased and healthy, age range 18-85 years—54 samples used in training; 54 used for testing). Main outcome measure Mean proportion of successes per dog achieved during evaluation, compared with an expected value of 1 in 7 (14%). Results Taken as a group, the dogs correctly selected urine from patients with bladder cancer on 22 out of 54 occasions. This gave a mean success rate of 41% (95% confidence intervals 23% to 58% under assumptions of normality, 26% to 52% using bootstrap methods), compared with 14% expected by chance alone. Multivariate analysis suggested that the dogs' capacity to recognise a characteristic bladder cancer odour was independent of other chemical aspects of the urine detectable by urinalysis. Conclusions Dogs can be trained to distinguish patients with bladder cancer on the basis of urine odour more successfully than would be expected by chance alone. This suggests that tumour related volatile compounds are present in urine, imparting a characteristic odour signature distinct from those associated with secondary effects of the tumour, such as bleeding, inflammation, and infection. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3275 | null | The Effect of Replacement of Methionine by Homocystine on Survival of Malignant and Normal Adult Mammalian Cells in Culture
In tissue cultures of normal adult and malignant mammalian cells, homocystine has been substituted for methionine in a medium rich in folic acid and cyanocobalamin. Normal adult cells thrive. Three highly malignant cell types from three different species, including man, die. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3276 | null | A review of methionine dependency and the role of methionine restriction in cancer growth control and life-span extension.
Methionine is an essential amino acid with many key roles in mammalian metabolism such as protein synthesis, methylation of DNA and polyamine synthesis. Restriction of methionine may be an important strategy in cancer growth control particularly in cancers that exhibit dependence on methionine for survival and proliferation. Methionine dependence in cancer may be due to one or a combination of deletions, polymorphisms or alterations in expression of genes in the methionine de novo and salvage pathways. Cancer cells with these defects are unable to regenerate methionine via these pathways. Defects in the metabolism of folate may also contribute to the methionine dependence phenotype in cancer. Selective killing of methionine dependent cancer cells in co-culture with normal cells has been demonstrated using culture media deficient in methionine. Several animal studies utilizing a methionine restricted diet have reported inhibition of cancer growth and extension of a healthy life-span. In humans, vegan diets, which can be low in methionine, may prove to be a useful nutritional strategy in cancer growth control. The development of methioninase which depletes circulating levels of methionine may be another useful strategy in limiting cancer growth. The application of nutritional methionine restriction and methioninase in combination with chemotherapeutic regimens is the current focus of clinical studies. Copyright © 2012 Elsevier Ltd. All rights reserved. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3277 | null | Expression of the biochemical defect of methionine dependence in fresh patient tumors in primary histoculture.
Methionine dependence is a metabolic defect that occurs in many human tumor cell lines but not normal in unestablished cell strains. Methionine-dependent tumor cell lines are unable to proliferate and arrest in the late S/G2 phase of the cell cycle when methionine is replaced by its immediate precursor homocysteine in the culture medium (MET-HCY+ medium). However, it is not known whether methionine dependence occurs in fresh patient tumors as it does in cell lines. In order to determine whether methionine dependence occurs in fresh patient tumors as well as whether methionine dependence occurs in fresh patient tumors as well as in cell lines we took advantage of the technique of sponge-gel-supported histoculture to grow tumors directly from surgery. We then measured nuclear DNA content by image analysis to determine the cell cycle position in MET-HCY+ compared to MET+HCY- medium in 21 human patient tumors. Human tumor cell lines found to be methionine dependent by cell count were used as positive controls and were found to have marked reduction of cells in G1 compared to total cells in the cell cycle in MET-HCY+ medium with respect to the G1: total cell ratio in MET+HCY- medium. Therefore late cell cycle arrest was used as a marker of methionine dependence for histocultured patient tumors. We found that 5 human tumors of 21, including tumors of the colon, breast, ovary, prostate, and a melanoma, were methionine dependent based on cell cycle analysis. These data on fresh human tumors indicate that methionine dependence may frequently occur in the cancer patient population. Implications for potential therapy based on methionine dependence are discussed. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3278 | null | Sniffer dogs as part of a bimodal bionic research approach to develop a lung cancer screening
Lung cancer (LC) continues to represent a heavy burden for health care systems worldwide. Epidemiological studies predict that its role will increase in the near future. While patient prognosis is strongly associated with tumour stage and early detection of disease, no screening test exists so far. It has been suggested that electronic sensor devices, commonly referred to as ‘electronic noses’, may be applicable to identify cancer-specific volatile organic compounds in the breath of patients and therefore may represent promising screening technologies. However, three decades of research did not bring forward a clinically applicable device. Here, we propose a new research approach by involving specially trained sniffer dogs into research strategies by making use of their ability to identify LC in the breath sample of patients. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3279 | null | Chitin synthesis and degradation as targets for pesticide action.
Various pesticides are being used to destabilize, perturb, or inhibit crucial biochemical and physiological targets related to metabolism, growth, development, nervous communication, or behavior in pestiferous organisms. Chitin is an eukaryotic extracellular aminosugar biopolymer, massively produced by most fungal systems and by invertebrates, notably arthropods. Being an integral supportive component in fungal cell wall, insect cuticle, and nematode egg shell, chitin has been considered as a selective target for pesticide action. Throughout the elaborate processes of chitin formation and deposition, only the polymerization events associated with the cell membrane compartment are so far available for chemical interference. Currently, the actinomycetes-derived nucleoside peptide fungicides such as the polyoxins and the insecticidal benzoylaryl ureas have reached commercial pesticide status. The polyoxins and other structurally-related antibiotics like nikkomycins are strong competitive inhibitors of the polymerizing enzyme chitin synthase. The exact biochemical lesion inflicted by the benzoylaryl ureas is still elusive, but a post-polymerization event, such as translocation of chitin chains across the cell membrane, is suggested. Hydrolytic degradation of the chitin polymer is essential for hyphal growth, branching, and septum formation in fungal systems as well as for the normal molting of arthropods. Recently, insect chitinase activity was strongly and specifically suppressed by allosamidin, an actimomycetes-derived metabolite. In part, the defense mechanism in plants against invasion of pathogens is associated with induced chitinases. Chitin, chitosan, and their oligomers are able to act as elicitors which induce enhanced levels of chitinases in various plants. Lectins which bind to N-acetyl-D-glucosamine strongly interfere with fungal and insect chitin synthases. Plant lectins with similar properties may be involved in plant-pathogen interaction inter alia by suppressing fungal invasion. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
nfcorpus-corpus-MED-3280 | null | Methionine dependency and cancer treatment.
Conventional chemotherapies have showed their limits, notably for patients with advanced cancer. New therapeutic strategies must be identified, and the metabolic abnormalities of cancer cells offer such opportunities. Many human cancer cell lines and primary tumors have absolute requirements for methionine, an essential amino acid. In contrast, normal cells are relatively resistant to exogenous methionine restriction. The biochemical mechanism for methionine dependency has been studied extensively, but the fundamental mechanism remains unclear. A number of investigators have attempted to exploit the methionine dependence of tumors for therapeutic effects in vivo. To reduce in vivo methionine in plasma and tumours, dietary and pharmacological treatments have been used. Methionine-free diet or methionine-deprived total parenteral nutrition causes regression of a variety of animal tumours. Alternatively, methionine depletion was achieved by the use of methioninase. This enzyme specifically degrades methionine and inhibits tumour growth in preclinical models. Because of potential toxicity and quality of life problems, prolonged methionine restriction with diet or with methioninase is not suitable for clinical use. Methionine restriction may find greater application in association with various chemotherapeutic agents. Several preclinical studies have demonstrated synergy between methionine restriction and various cytotoxic chemotherapy drugs. The experimental results accumulated during the last three decades suggest that methionine restriction can become an additional cancer therapeutic strategy, notably in association with chemotherapy. |
nfcorpus-queries-PLAIN-2590 | null | Do Vegetarians Get Enough Protein? |
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