Instruct: Given a question, retrieve passages that answer the question.
Query: Preserving Vision Through Diet
High-dose β-carotene supplementation in high-risk persons has been linked to increased lung cancer risk in clinical trials; whether effects are similar in the general population is unclear. The authors examined associations of supplemental β-carotene, retinol, vitamin A, lutein, and lycopene with lung cancer risk among participants, aged 50–76 years, in the VITamins And Lifestyle (VITAL) cohort Study in Washington State. In 2000–2002, eligible persons (n = 77,126) completed a 24-page baseline questionnaire, including detailed questions about supplement use (duration, frequency, dose) during the previous 10 years from multivitamins and individual supplements/mixtures. Incident lung cancers (n = 521) through December 2005 were identified by linkage to the Surveillance, Epidemiology, and End Results cancer registry. Longer duration of use of individual β-carotene, retinol, and lutein supplements (but not total 10-year average dose) was associated with statistically significantly elevated risk of total lung cancer and histologic cell types; for example, hazard ratio = 2.02, 95% confidence interval: 1.28, 3.17 for individual supplemental lutein with total lung cancer and hazard ratio = 3.22, 95% confidence interval: 1.29, 8.07 for individual β-carotene with small-cell lung cancer for >4 years versus no use. There was little evidence for effect modification by gender or smoking status. Long-term use of individual β-carotene, retinol, and lutein supplements should not be recommended for lung cancer prevention, particularly among smokers.
Consumption of Phaseolus vulgaris bean species such as pinto, black, navy or kidney may be beneficial in the prevention and treatment of chronic diseases. In particular, conditions that are promoted by increased glycaemic stress (hyperglycaemia and hyperinsulinaemia) including diabetes, CVD and cancer seem to be reduced in individuals who eat more of these beans. The present paper discusses the influence of P. vulgaris species on glycaemic response and the impact that relationship may have on the risk of developing diabetes, CVD and cancer.
Dioxins and related compounds are undesirable and unintended contaminants in the food supply, and dietary intake is the major route of exposure. Reducing dietary exposure to dioxins among the most vulnerable segments of the population (i.e., pregnant women, infants, and young girls) is an effective strategy for reducing body burdens in future generations. Exposure to dioxins through foods can be minimized by selecting lower-fat versions of meats, poultry, and dairy products. Consuming all foods, including fatty fish, in recommended amounts is congruent with the goal of reducing dioxin intake exposure and maintaining good health.
A widespread misconception has been developing among the Canadian public and among physicians. It is increasingly believed that consumption of dietary cholesterol and egg yolks is harmless. There are good reasons for long-standing recommendations that dietary cholesterol should be limited to less than 200 mg/day; a single large egg yolk contains approximately 275 mg of cholesterol (more than a day’s worth of cholesterol). Although some studies showed no harm from consumption of eggs in healthy people, this outcome may have been due to lack of power to detect clinically relevant increases in a low-risk population. Moreover, the same studies showed that among participants who became diabetic during observation, consumption of one egg a day doubled their risk compared with less than one egg a week. Diet is not just about fasting cholesterol; it is mainly about the postprandial effects of cholesterol, saturated fats, oxidative stress and inflammation. A misplaced focus on fasting lipids obscures three key issues. Dietary cholesterol increases the susceptibility of low-density lipoprotein to oxidation, increases postprandial lipemia and potentiates the adverse effects of dietary saturated fat. Dietary cholesterol, including egg yolks, is harmful to the arteries. Patients at risk of cardiovascular disease should limit their intake of cholesterol. Stopping the consumption of egg yolks after a stroke or myocardial infarction would be like quitting smoking after a diagnosis of lung cancer: a necessary action, but late. The evidence presented in the current review suggests that the widespread perception among the public and health care professionals that dietary cholesterol is benign is misplaced, and that improved education is needed to correct this misconception. Résumé Une idée fausse et généralisée se répand au sein du public canadien et des médecins, qui pensent de plus en plus que la consommation de cholestérol alimentaire et de jaunes d’œuf est inoffensive. Les recommandations de longue date qui préconisent de limiter le cholestérol alimentaire à moins de 200 mg/jour reposent sur de bonnes raisons. Un seul gros jaune d’œuf contient environ 275 mg de cholestérol (plus que la portion quotidienne de cholestérol). Même si certaines études ont démontré que la consommation d’œufs n’est pas nuisible chez les personnes en santé, ce résultat peut découler de l’absence de capacité à déceler des augmentations pertinentes sur le plan clinique au sein d’une population à faible risque. De plus, les mêmes études ont révélé que chez les participants devenus diabétiques pendant la période d’observation, la consommation d’un œuf par jour doublait leur risque par rapport à la consommation de moins d’un œuf par semaine. Le régime ne vise pas à éviter le cholestérol, mais surtout les effets postprandiaux du cholestérol, des gras saturés, du stress oxydant et de l’inflammation. Le fait de se concentrer à tort sur les lipides à jeun occulte trois enjeux. Le cholestérol alimentaire accroît la susceptibilité des lipoprotéines à faible densité à l’oxydation, accroît la lipémie postprandiale et potentialise les effets secondaires des graisses saturées alimentaires. Le cholestérol alimentaire, y compris les jaunes d’œuf, est nuisible pour les artères. Les patients vulnérables aux maladies cardiovasculaires devraient limiter leur consommation de cholestérol. Le fait d’arrêter de consommer des jaunes d’œuf après un accident vasculaire cérébral ou un infarctus du myocarde s’apparenterait à arrêter de fumer après un diagnostic de cancer du poumon : c’est un geste nécessaire, mais entrepris tardivement. D’après les données probantes présentées dans la présente analyse, la perception généralisée du public et des professionnels de la santé selon laquelle le cholestérol alimentaire est un mal bénin est une idée fausse, et une meilleure information s’impose pour la corriger.
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.
OBJECTIVE: Determine 1) if consumption of a meal of different fruits or berries increases plasma hydrophilic (H-) or lipophilic (L-) antioxidant capacity (AOC) measured as Oxygen Radical Absorbance Capacity (ORAC(FL)); 2) if including macronutrients in the meal alters postprandial changes in AOC; and 3) if preliminary recommendations can be developed for antioxidant intake. METHODS: Changes in plasma AOC following consumption of a single meal of berries/fruits (blueberry, dried plum, dried plum juice, grape, cherry, kiwifruit and strawberry) were studied in 5 clinical trials with 6-10 subjects per experiment. In two studies with blueberry or grape, additional macronutrients (carbohydrate, fat, protein) were included in the control and treatment meals. Blood samples collected before and after the meal were analyzed for AOC. RESULTS: Consumption of dried plums or dried plum juice did not alter either the H- or L-AOC area under the curve (AUC). Consumption of blueberry in 2 studies and of mixed grape powder [12.5 (Study #1), 39.9 (Study #4) and 8.6 (Study #5) mmole Trolox Equivalents (TE) AOC, respectively] increased hydrophilic AOC AUC. L-AOC increased following a meal of blueberry containing 12.5 mmole TE AOC (Study #1). Consumption of 280 g of cherries (4.5 mmol TE AOC) increased plasma L-AOC but not H-AOC. The AOC in the control groups in which additional macronutrients (Studies #4 and #5) were added decreased from the postprandial baseline AOC measurement. CONCLUSION: We have demonstrated that consumption of certain berries and fruits such as blueberries, mixed grape and kiwifruit, was associated with increased plasma AOC in the postprandial state and consumption of an energy source of macronutrients containing no antioxidants was associated with a decline in plasma AOC. However, without further long term clinical studies, one cannot necessarily translate increased plasma AOC into a potential decreased risk of chronic degenerative disease. Preliminary estimates of antioxidant needs based upon energy intake were developed. Consumption of high antioxidant foods with each meal is recommended in order to prevent periods of postprandial oxidative stress.
Dietary consumption of fish is widely recommended because of the beneficial effects of omega-3 polyunsaturated fatty acids on the risks of cardiovascular and Alzheimer's diseases. The American Heart Association currently recommends eating at least two servings of fish per week. We are concerned that consumption of farmed fish may provide a means of transmission of infectious prions from cows with bovine spongiform encephalopathy to humans, causing variant Creutzfeldt Jakob disease.
Xerophthalmia and keratomalacia are public health problems of great magnitude which are usually associated with multiple vitamin and protein deficiencies. The authors report the case of a 27-year-old commune member who subjected herself to a bizarre protein and vitamin deficient diet for many months. This ultimately produced nyctalopia, xerophthalmia and keratomalacia with bilateral corneal perforation. Despite therapy, she remained comatose and expired shortly after admission. Ocular pathological changes included bilateral corneal melting with prolapse of intraocular contents, conjunctival epidermidalization, goblet cell atrophy and thinning of the outer nuclear layer of the retina. It is noted that ocular findings in pure avitaminosis A produced experimentalyy include epithelial atrophy followed by keratinization.
Fruits and vegetables are among the most nutritious and healthy of foods, and are related to the prevention of many chronic diseases. The aim of the study was to examine the relationship between intake of different plant foods and cognitive performance in elderly individuals in a cross-sectional study. Two thousand and thirty-one elderly subjects (aged 70-74 years; 55% women) recruited from the general population in Western Norway underwent extensive cognitive testing and completed a comprehensive FFQ. The cognitive test battery covered several domains (Kendrick Object Learning Test, Trail Making Test--part A, modified versions of the Digit Symbol Test, Block Design, Mini-Mental State Examination and Controlled Oral Word Association Test). A validated and self-reported FFQ was used to assess habitual food intake. Subjects with intakes of >10th percentile of fruits, vegetables, grain products and mushrooms performed significantly better in cognitive tests than those with very low or no intake. The associations were strongest between cognition and the combined intake of fruits and vegetables, with a marked dose-dependent relationship up to about 500 g/d. The dose-related increase of intakes of grain products and potatoes reached a plateau at about 100-150 g/d, levelling off or decreasing thereafter, whereas the associations were linear for mushrooms. For individual plant foods, the positive cognitive associations of carrots, cruciferous vegetables, citrus fruits and high-fibre bread were most pronounced. The only negative cognitive association was with increased intake of white bread. In the elderly, a diet rich in plant foods is associated with better performance in several cognitive abilities in a dose-dependent manner.
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.
Effective diets reduce blood lipids and oxidative damage, both of which have been linked to the complications of diabetes and coronary heart disease. Our objective was to assess the effect of adding strawberries, as a source of antioxidants, to improve the antioxidant effect of a cholesterol-lowering diet (dietary portfolio). To this end, 28 hyperlipidemic subjects who had followed the dietary portfolio consisting of soy, viscous fiber, plant sterol, and nuts for a mean of 2.5 years were randomized to receive supplements of strawberries (454 g/d, 112 kcal) or additional oat bran bread (65 g/d, 112 kcal, approximately 2 g beta-glucan) (control) in a randomized 1-month crossover study with a 2-week washout. Strawberry supplementation resulted in a greater reduction in oxidative damage to low-density lipoprotein (LDL) measured as thiobarbituric acid-reactive substances in the LDL fraction (P = .014). At the end of the strawberry period, reductions in LDL cholesterol and in the ratio of total to high-density lipoprotein cholesterol were maintained close to 1-year values at -13.4% +/- 2.1% and -15.2% +/- 1.7%, respectively (P < .001), and were similar to the post-oat bran bread values. Strawberries also improved the palatability of the diet. We conclude that strawberry supplementation reduced oxidative damage to LDL while maintaining reductions in blood lipids and enhancing diet palatability. Added fruit may improve the overall utility of diets designed to lower coronary heart disease risk.
Background: Dietary antioxidants may protect against DNA damage induced by endogenous and exogenous sources, including ionizing radiation (IR), but data from IR-exposed human populations are limited. Objective: The objective was to examine the association between the frequency of chromosome translocations, as a biomarker of cumulative DNA damage, and intakes of vitamins C and E and carotenoids in 82 male airline pilots. Design: Dietary intakes were estimated by using a self-administered semiquantitative food-frequency questionnaire. Translocations were scored by using fluorescence in situ hybridization with whole chromosome paints. Negative binomial regression was used to estimate rate ratios and 95% CIs, adjusted for potential confounders. Results: Significant and inverse associations were observed between translocation frequency and intakes of vitamin C, β-carotene, β-cryptoxanthin, and lutein-zeaxanthin from food (P < 0.05). Translocation frequency was not associated with the intake of vitamin E, α-carotene, or lycopene from food; total vitamin C or E from food and supplements; or vitamin C or E or multivitamin supplements. The adjusted rate ratios (95% CI) for ≥median compared with <median servings per week of high–vitamin C fruit and vegetables, citrus fruit, and green leafy vegetables were 0.61 (0.43, 0.86), 0.64 (0.46, 0.89), and 0.59 (0.43, 0.81), respectively. The strongest inverse association was observed for ≥median compared with <median combined intakes of vitamins C and E, β-carotene, β-cryptoxanthin, and lutein-zeaxanthin from food: 0.27 (0.14, 0.55). Conclusion: High combined intakes of vitamins C and E, β-carotene, β-cryptoxanthin, and lutein-zeaxanthin from food, or a diet high in their food sources, may protect against cumulative DNA damage in IR-exposed persons.
Modern diets are largely heat-processed and as a result contain high levels of advanced glycation end products (AGEs). Dietary advanced glycation end products (dAGEs) are known to contribute to increased oxidant stress and inflammation, which are linked to the recent epidemics of diabetes and cardiovascular disease. This report significantly expands the available dAGE database, validates the dAGE testing methodology, compares cooking procedures and inhibitory agents on new dAGE formation, and introduces practical approaches for reducing dAGE consumption in daily life. Based on the findings, dry heat promotes new dAGE formation by >10- to 100-fold above the uncooked state across food categories. Animal-derived foods that are high in fat and protein are generally AGE-rich and prone to new AGE formation during cooking. In contrast, carbohydrate-rich foods such as vegetables, fruits, whole grains, and milk contain relatively few AGEs, even after cooking. The formation of new dAGEs during cooking was prevented by the AGE inhibitory compound aminoguanidine and significantly reduced by cooking with moist heat, using shorter cooking times, cooking at lower temperatures, and by use of acidic ingredients such as lemon juice or vinegar. The new dAGE database provides a valuable instrument for estimating dAGE intake and for guiding food choices to reduce dAGE intake.
A vegetarian diet generally includes plenty of vegetables and fruits, which are rich in phytochemicals, antioxidants, fiber, magnesium, vitamins C and E, Fe³⁺, folic acid and n-6 polyunsaturated fatty acid (PUFA), and is low in cholesterol, total fat and saturated fatty acid, sodium, Fe²⁺, zinc, vitamin A, B₁₂ and D, and especially n-3 PUFA. Mortality from all-cause, ischemic heart disease, and circulatory and cerebrovascular diseases was significantly lower in vegetarians than in omnivorous populations. Compared with omnivores, the incidence of cancer and type 2 diabetes was also significantly lower in vegetarians. However, vegetarians have a number of increased risk factors for non-communicable diseases such as increased plasma homocysteine, mean platelet volume and platelet aggregability compared with omnivores, which are associated with low intake of vitamin B₁₂ and n-3 PUFA. Based on the present data, it would seem appropriate for vegetarians to carefully design their diet, specifically focusing on increasing their intake of vitamin B₁₂ and n-3 PUFA to further reduce already low mortality and morbidity from non-communicable diseases. © 2013 Society of Chemical Industry.
Daily diet may have implications for skin ageing. However, data on the relationship between diet and the parameters of skin conditions are scarce. The present study aimed to examine the associations of biophysical properties of the skin of women with intakes of fats and antioxidant micronutrients as well as food groups as sources of these nutrients. In a cross-sectional study, we measured the hydration, surface lipids and elasticity of the skin of 716 Japanese women using non-invasive techniques. The extent of facial wrinkles in the crow's-foot area was determined by observation using the Daniell scale. Each subject's usual diet was determined with the use of a validated FFQ. After controlling for covariates including age, smoking status, BMI and lifetime sun exposure, the results showed that higher intakes of total fat, saturated fat and monounsaturated fat were significantly associated with increased skin elasticity. A higher intake of green and yellow vegetables was significantly associated with a decreased Daniell wrinkling score. Intake of saturated fat was significantly inversely associated with the Daniell wrinkling score after additional adjustment for green and yellow vegetable intake. Further studies with more accurate measurement methods are needed to investigate the role of daily diet in skin ageing.
A comprehensive ecologic survey of dietary, life-style, and mortality characteristics of 65 counties in rural China showed that diets are substantially richer in foods of plant origin when compared with diets consumed in the more industrialized, Western societies. Mean intakes of animal protein (about one-tenth of the mean intake in the United States as energy percent), total fat (14.5% of energy), and dietary fiber (33.3 g/d) reflected a substantial preference for foods of plant origin. Mean plasma cholesterol concentration, at approximately 3.23-3.49 mmol/L, corresponds to this dietary life-style. The principal hypothesis under investigation in this paper is that chronic degenerative diseases are prevented by an aggregate effect of nutrients and nutrient-intake amounts that are commonly supplied by foods of plant origin. The breadth and consistency of evidence for this hypothesis was investigated with multiple intake-biomarker-disease associations, which were appropriately adjusted. There appears to be no threshold of plant-food enrichment or minimization of fat intake beyond which further disease prevention does not occur. These findings suggest that even small intakes of foods of animal origin are associated with significant increases in plasma cholesterol concentrations, which are associated, in turn, with significant increases in chronic degenerative disease mortality rates.
Inflammation is a pathological condition underlying a number of diseases including cardiovascular diseases, cancer, and chronic inflammatory diseases. In addition, healthy, obese subjects also express markers of inflammation in their blood. Diet provides a variety of nutrients as well as non-nutritive bioactive constituents which modulate immunomodulatory and inflammatory processes. Epidemiological data suggest that dietary patterns strongly affect inflammatory processes. Primarily the intake of fruit and vegetables as well as of whole wheat is inversely associated with the risk of inflammation. In addition to observational studies there are also data from human intervention studies suggesting an anti-inflammatory potential of these plant foods. At the level of bioactive compounds occurring in plant foods, primarily carotenoids and flavonoids seem to modulate inflammatory as well as immunological processes. In conclusion, there is convincing evidence that plant foods and non-nutritive constituents associated with these foods modulate immunological and inflammatory processes. By means of anti-inflammatory activities a plant-based diet may contribute to the lower risk of cardiovascular diseases and cancer. A high intake of vegetables, fruit, and whole wheat as recommended by all international nutrition authorities provides a wide spectrum of bioactive compounds at health-promoting concentrations.
Vitamin A deficiency (VAD) has been recognized as a public-health issue in developing countries. Economic constraints, sociocultural limitations, insufficient dietary intake, and poor absorption leading to depleted vitamin A stores in the body have been regarded as potential determinants of the prevalence of VAD in South Asian developing countries. VAD is exacerbated by lack of education, poor sanitation, absence of new legislation and enforcement of existing food laws, and week monitoring and surveillance system. Several recent estimates confirmed higher morbidly and mortality rate among children and pregnant and non-pregnant women of childbearing age. Xerophthalmia is the leading cause of preventable childhood blindness with its earliest manifestations as night blindness and Bitot's spots, followed by blinding keratomalacia, all of which are the ocular manifestations of VAD. Children need additional vitamin A because they do not consume enough in their normal diet. There are three general ways for improving vitamin A status: supplementation, fortification, and dietary diversification. These approaches have not solved the problem in South Asian countries to the desired extent because of poor governmental support and supervision of vitamin A supplementation twice a year. An extensive review of the extant literature was carried out, and the data under various sections were identified by using a computerized bibliographic search via PubMed, Web of Science, and Google Scholar. All abstracts and full-text articles were examined, and the most relevant articles were selected for screening and inclusion in this review. Conclusively, high prevalence of VAD in South Asian developing countries leads to increased morbidity and mortality among infants, children, and pregnant women. Therefore, stern efforts are needed to address this issue of public-health significance at local and international level in lower- and middle-income countries of South Asia.
Recent advances have been made in our scientific understanding of how berries promote human health and prevent chronic illnesses such as some cancers, heart disease, and neurodegenerative diseases. Cancer is rapidly overtaking heart disease as the number one killer disease in developed countries, and this phenomenon is coupled with a growing aging population and concomitant age-related diseases. Therefore, it is not surprising that consumers are turning toward foods with medicinal properties as promising dietary interventions for disease prevention and health maintenance. Among fruits, berries of all colors have emerged as champions with substantial research data supporting their abilities to positively affect multiple disease states. Apart from several essential dietary components found in berries, such as vitamins, minerals, and fiber, berries also contain numerous bioactives that provide health benefits that extend beyond basic nutrition. Berry bioactives encompass a wide diversity of phytochemicals (phytonutrients) ranging from fat-soluble/lipophilic to water-soluble/hydrophilic compounds. Recent research from laboratories across the globe has provided useful insights into the biological effects and underlying mechanisms of actions resulting from eating berries. The cluster of papers included here represents a cross section of topics discussed at the 2009 International Berry Health Benefits Symposium. Together, these papers provide valuable insight into recent research trends and advances made into evaluating the various health benefits that may result from the consumption of berries and their derived products.
The relation between dietary antioxidant intake and primary open-angle glaucoma risk was examined in participants aged over 40 years in the Nurses' Health Study (n = 76,200) and the Health Professionals Follow-up Study (n = 40,284). They were followed biennially from 1980 and 1986, respectively, to 1996, during periods when they received an eye examination. Dietary intakes were measured repeatedly from 1980 in the Nurses' Health Study and from 1986 in the Health Professionals Follow-up Study using validated food frequency questionnaires. The authors analyzed 474 self-reported glaucoma cases confirmed by medical chart review to have primary open-angle glaucoma with visual field loss. The authors used Cox proportional hazards models for cohort-specific multivariate analyses, and results were pooled using random effects models. The pooled multivariate rate ratios for primary open-angle glaucoma comparing the highest versus lowest quintile of cumulative updated intake were 1.17 (95% confidence interval (CI): 0.87, 1.58) for alpha-carotene, 1.10 (95% CI: 0.82, 1.48) for beta-carotene, 0.95 (95% CI: 0.70, 1.29) for beta-cryptoxanthin, 0.82 (95% CI: 0.60, 1.12) for lycopene, 0.92 (95% CI: 0.69, 1.24) for lutein/zeaxanthin, 1.05 (95% CI: 0.59, 1.89) for vitamin C, 0.97 (95% CI: 0.62, 1.52) for vitamin E, and 1.11 (95% CI: 0.82, 1.51) for vitamin A. In conclusion, the authors did not observe any strong associations between antioxidant consumption and the risk of primary open-angle glaucoma.
The Kuna Indians who reside in an archipelago on the Caribbean Coast of Panama have very low blood pressure levels, live longer than other Panamanians, and have a reduced frequency of myocardial infarction, stroke, diabetes mellitus, and cancer -- at least on their death certificates. One outstanding feature of their diet includes a very high intake of flavanol-rich cocoa. Flavonoids in cocoa activate nitric oxide synthesis in healthy humans. The possibility that the high flavanol intake protects the Kuna against high blood pressure, ischemic heart disease, stroke, diabetes mellitus, and cancer is sufficiently intriguing and sufficiently important that large, randomized controlled clinical trials should be pursued.
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.
Presence of omega-3, omega-6 rich oil, alpha-linoleic acid, dietary fibers, secoisolariciresinol diglucoside, protein and minerals in flaxseed constitute a very strong basis for the utilization of flaxseed in various food preparations as a curative agent. An extensive body of literature illustrates that flaxseed has gained a significant position in the domain of nutritional sciences owing to its pivotal role as an antioxidant agent. The review discusses at length, numerous health benefits of flaxseed typically focusing its preventive role against cardiovascular diseases, cancer, diabetes and enhancement of spatial memory. Massive increase in the size of population with a special emphasize to the developing countries, there is an urge for exploration of the alternative dietary resources that can meet the dietary and nutritional needs of forthcoming generations. With respect to its remarkable nutritional importance, the review in question enables researchers engaged in nutritional sciences to further investigate the therapeutic value of flaxseed functional components and their dietary application in various food products and availability in processed foods as well as in the human cell line.
Estimation of total antioxidant intake is the first step to investigate the protective effects of antioxidants on oxidative stress-mediated disease. The present study was designed to develop an algorithm to estimate total antioxidant capacity (TAC) of the US diet. TAC of individual antioxidants and 50 popular antioxidant-rich food items in the US diet were determined by 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assay and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Theoretical TAC of foods was calculated as the sum of individual antioxidant capacities of compounds. The top 10 TAC food items in the US diet according to standard serving size were blueberry > plum > green tea > strawberry > green tea (decaffeinated) > red wine > grape juice > black tea > cherry > grape. Major contributors to TAC were the total phenolic content (r = 0.952, P < 0.001) and flavonoid content (r = 0.827, P < 0.001) of 50 foods. Theoretical TAC was positively correlated to experimental TAC of 50 foods determined by the ABTS assay (r = 0.833, P < 0.001) and the DPPH assay (r = 0.696, P < 0.001), and to TAC from the USDA database for the oxygen radical absorbance capacity (r = 0.484, P = 0.001, n = 44). The TAC database of the US diet has been established and validated. In future studies, TAC of the US diet can be linked to biomarkers of chronic disease.
Restriction of food intake by 10-50% of ad libitum on a per unit of weight or energy content basis can extend the lifespan of a wide variety of species and prevent or delay age-related disease. This review first briefly summarizes the data delineating mortality trajectories of various species' populations maintained on restricted diets to provide insight into the effects of nutrient deprivation on distinct components of the aging process. Next, I discuss a number of important studies that have addressed the question whether it is the lack of calories and/or specific nutrients that determines the longevity response to dietary restriction. Finally, I review the evidence for hormesis as a proximate mechanism underpinning the impact of dietary restriction on lifespan. In aggregate, the currently available demographic data suggest that dietary restriction can both slow the age-related progressive accumulation of cellular damage and also enhance the ability of organisms to cope with irreversible injury. Restriction of essential nutrients as well as calories may affect life expectancy, perhaps in a species specific fashion. Hormesis, i.e. an evolutionary conserved stress response routine providing protection against a wide variety of (other) hazards in response to low levels of stress, is very likely to contribute to the beneficial health effects of dietary restriction. Copyright Â© 2011 Elsevier Inc. All rights reserved.