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Folic acid is required for the methylation of homocysteine to methionine. Learn more about ReliefWeb. Hidden dangers in Florence's floodwaters. The only dietary factors which have been shown to increase the risk for breast cancer are obesity and alcohol. Dorgan JF et al.
Obesity, fat distribution, and weight gain as risk factors for clinical diabetes in men. Boyko EJ et al. Visceral adiposity and risk of type 2 diabetes: Health consequences of visceral obesity. Annals of Medicine , , McAuley KA et al. Intensive lifestyle changes are necessary to improve insulin sensitivity. Tuomilehto J et al. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance.
Knowler WC et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention of metformin. A prospective study of exercise and incidence of diabetes among US male physicians.
Kriska AM et al. The association of physical activity with obesity, fat distribution and glucose intolerance in Pima Indians. Diabetologia , , Helmrich SP et al.
Physical activity and reduced occurrence of non-insulindependent diabetes mellitus. Pettitt DJ et al. Role of intrauterine environment. Diabetes , , Dabelea D et al. Intrauterine exposure to diabetes conveys risks for type 2 diabetes and obesity: Feskens EJM et al. Dietary factors determining diabetes and impaired glucose tolerance. Bo S et al. Dietary fat and gestational hyperglycaemia. Habitual dietary intake and glucose tolerance in euglycaemic men: International Journal of Epidemiology , , Parker DR et al.
Relationship of dietary saturated fatty acids and body habitus to serum insulin concentrations: Folsom AR et al. Relation between plasma phospholipid saturated fatty acids and hyperinsulinemia.
Metabolism , , Insulin sensitivity is related to the fatty acid composition of serum lipids and skeletal muscle phospholipids in year-old men. Vessby B et al. Salmeron J et al. Dietary fat intake and risk of type 2 diabetes in women. Meyer KA et al. Dietary fat and incidence of type 2 diabetes in older Iowa women. Mooy JM et al. Prevalence and determinants of glucose intolerance in a Dutch Caucasian population. Pan DA et al. Skeletal muscle membrane lipid composition is related to adiposity and insulin action.
Journal of Clinical Investigation , , Uusitupa M et al. Effects of two high-fat diets with different fatty acid compositions on glucose and lipid metabolism in healthy young women. Substituting polyunsaturated for saturated fat as a single change in a Swedish diet: European Journal of Clinical Investigation , , Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: Marshall JA et al.
Mayer EJ et al. Usual dietary fat intake and insulin concentrations in healthy women twins. Lovejoy J, DiGirolamo M. Habitual dietary intake and insulin sensitivity in lean and obese adults. Dietary-fiber hypothesis of the etiology of diabetes mellitus. Dietary fiber, glycemic load, and risk of non-insulin-dependent diabetes mellitus in women. Carbohydrates, dietary fiber, and incident type 2 diabetes in older women.
Dietary fibre and diabetes revisited. Simpson HRC et al. A high carbohydrate leguminous fibre diet improves all aspects of diabetic control. Diabetic Medicine , , 1: Chandalia M et al. Beneficial effects of high dietary fiber intake in patients with type 2 diabetes mellitus.
Dietary advice based on the glycaemic index improves dietary profile and metabolic control in type 2 diabetic patients. Diabetic Medicine , , Brand JC et al. Fontvieille AM et al. The use of low glycaemic index foods improves metabolic control of diabetic patients over five weeks. Diabetic Medicine , , 9: Wolever TMS et al. Beneficial effect of a low glycaemic index diet in type 2 diabetes. Stern MP et al. Birth weight and the metabolic syndrome: Infant and young child nutrition.
The second half of the 20th century has witnessed major shifts in the pattern of disease, in addition to marked improvements in life expectancy, this period is characterized by profound changes in diet and lifestyles which in turn have contributed to an epidemic of noncommunicable diseases.
This epidemic is now emerging, and even accelerating, in most developing countries, while infections and nutritional deficiencies are receding as leading contributors to death and disability 1. In developing countries, the effect of the nutrition transition and the concomitant rise in the prevalence of cardiovascular diseases will be to widen the mismatch between health care needs and resources, and already scarce resources will be stretched ever more thinly.
Because unbalanced diets, obesity and physical inactivity all contribute to heart disease, addressing these, along with tobacco use, can help to stem the epidemic. A large measure of success in this area has already been demonstrated in many industrialized countries. Cardiovascular diseases are the major contributor to the global burden of disease among the noncommunicable diseases.
WHO currently attributes one-third of all global deaths In the next two decades the increasing burden of CVD will be borne mostly by developing countries. Overweight, central obesity, high blood pressure, dyslipidaemia, diabetes and low cardio-respiratory fitness are among the biological factors contributing principally to increased risk. Unhealthy dietary practices include the high consumption of saturated fats, salt and refined carbohydrates, as well as low consumption of fruits and vegetables, and these tend to cluster together.
Convincing associations for reduced risk of CVD include consumption of fruits including berries and vegetables, fish and fish oils eicosapentaenoic acid EPA and docosahexaenoic acid DHA , foods high in linoleic acid and potassium, as well as physical activity and low to moderate alcohol intake.
While vitamin E intake appears to have no relationship to risk of CVD, there is convincing evidence that myristic and palmitic acids, trans fatty acids, high sodium intake, overweight and high alcohol intake contribute to an increase in risk. There is a probable increase in risk from dietary cholesterol and unfiltered boiled coffee.
Possible associations for reduced risk include intake of flavonoids and consumption of soy products, while possible associations for increased risk include fats rich in lauric acid, b-carotene supplements and impaired fetal nutrition. The evidence supporting these conclusions is summarized below. The relationship between dietary fats and CVD, especially coronary heart disease, has been extensively investigated, with strong and consistent associations emerging from a wide body of evidence accrued from animal experiments, as well as observational studies, clinical trials and metabolic studies conducted in diverse human populations 2.
Saturated fatty acids raise total and low-density lipoprotein LDL cholesterol, but individual fatty acids within this group, have different effects Myristic and palmitic acids have the greatest effect and are abundant in diets rich in dairy products and meat.
Stearic acid has not been shown to elevate blood cholesterol and is rapidly converted to oleic acid in vivo. The most effective replacement for saturated fatty acids in terms of coronary heart disease outcome are polyunsaturated fatty acids, especially linoleic acid. This finding is supported by the results of several large randomized clinical trials, in which replacement of saturated and trans fatty acids by polyunsaturated vegetable oils lowered coronary heart disease risk 6.
Trans fatty acids are geometrical isomers of cis-unsaturated fatty acids that adapt a saturated fatty acid-like configuration.
Partial hydrogenation, the process used to increase shelf-life of polyunsaturated fatty acids PUFAs creates trans fatty acids and also removes the critical double bonds in essential fatty acids necessary for the action.
Metabolic studies have demonstrated that trans fatty acids render the plasma lipid profile even more atherogenic than saturated fatty acids, by not only elevating LDL cholesterol to similar levels but also by decreasing highdensity lipoprotein HDL cholesterol 7.
Several large cohort studies have found that intake of trans fatty acids increases the risk of coronary heart disease 8, 9. Most trans fatty acids are contributed by industrially hardened oils. Even though trans fatty acids have been reduced or eliminated from retail fats and spreads in many parts of the world, deep-fried fast foods and baked goods are a major and increasing source 7. When substituted for saturated fatty acids in metabolic studies, both monounsaturated fatty acids and n-6 polyunsaturated fatty acids lower plasma total and LDL cholesterol concentrations 10 ; PUFAs are somewhat more effective than monounsaturates in this respect.
The only nutritionally important monounsaturated fatty acids is oleic acid, which is abundant in olive and canola oils and also in nuts. The most important polyunsaturated fatty acid is linoleic acid, which is abundant especially in soybean and sunflower oils.
The most important n-3 PUFAs are eicosapentaenoic acid and docosahexaenoic acid found in fatty fish, and a-linolenic acid found in plant foods. The biological effects of n-3 PUFAs are wide ranging, involving lipids and lipoproteins, blood pressure, cardiac function, arterial compliance, endothelial function, vascular reactivity and cardiac electrophysiology, as well as potent antiplatelet and anti-inflammatory effects The very long chain n-3 PUFAs eicosapentaenoic acid and docosahexaenoic acid powerfully lower serum triglycerides but they raise serum LDL cholesterol.
Therefore, their effect on coronary heart disease is probably mediated through pathways other than serum cholesterol. Most of the epidemiological evidence related to n-3 PUFAs is derived from studies of fish consumption in populations or interventions involving fish diets in clinical trials evidence on fish consumption is discussed further below. Several prospective studies have found an inverse association between the intake of a-linolenic acid, high in flaxseed, canola and soybean oils , and risk of fatal coronary heart disease 13, Cholesterol in the blood and tissues is derived from two sources: Dairy fat and meat are major dietary sources.
Egg yolk is particularly rich in cholesterol but unlike dairy products and meat does not provide saturated fatty acids. Although dietary cholesterol raises plasma cholesterol levels 15 , observational evidence for an association of dietary cholesterol intake with CVD is contradictory There is no requirement for dietary cholesterol and it is advisable to keep the intake as low as possible 2.
If intake of dairy fat and meat are controlled, there is no need to severely restrict egg yolk intake, although some limitation remains prudent. Dietary plant sterols, especially sitostanol, reduce serum cholesterol by inhibiting cholesterol absorption The cholesterol-lowering effects of plant sterols has also been well documented 18 and commercial products made of these compounds are widely available, but their longterm effects remain to be seen.
Dietary fibre is a heterogeneous mixture of polysaccharides and lignin that cannot be degraded by the endogenous enzymes of vertebrate animals. Water-soluble fibres include pectins, gums, mucilages and some hemicelluloses. Insoluble fibres include cellulose and other hemicelluloses. Most fibres reduce plasma total and LDL cholesterol, as reported by several trials Several large cohort studies carried out in different countries have reported that a high fibre diet as well as a diet high in wholegrain cereals lowers the risk of coronary heart disease Even though antioxidants could, in theory, be protective against CVD and there is observational data supporting this theory, controlled trials employing supplements have been disappointing.
The Heart Outcomes Prevention Evaluation trial HOPE , a definitive clinical trial relating vitamin E supplementation to CVD outcomes, revealed no effect of vitamin E supplementation on myocardial infarction, stroke or death from cardiovascular causes in men or women Also, the results of the Heart Protection Study indicated that no significant benefits of daily supplementation of vitamin E, vitamin C and b-carotene were observed among the high-risk individuals that were the subject of the study In several studies where dietary vitamin C reduced the risk of coronary heart disease, supplemental vitamin C had little effect.
Clinical trial evidence is lacking at present. Observational cohort studies have suggested a protective role for carotenoids but a meta-analysis of four randomized trials, in contrast, reported an increased risk of cardiovascular death The relationship of folate to CVD has been mostly explored through its effect on homocysteine, which may itself be an independent risk factor for coronary heart disease and probably also for stroke.
Folic acid is required for the methylation of homocysteine to methionine. Reduced plasma folate has been strongly associated with elevated plasma homocysteine levels and folate supplementation has been demonstrated to decrease those levels However, the role of homocysteine as an independent risk factor for CVD has been subject to much debate, since several prospective studies have not found this association to be independent of other risk factors 28, It has also been suggested that elevation of plasma homocysteine is a consequence and not a cause of atherosclerosis, wherein impaired renal function resulting from atherosclerosis raises plasma homocysteine levels 30, A recently published metaanalysis concluded that a higher intake of folate 0.
Flavonoids are polyphenolic compounds that occur in a variety of foods of vegetable origin, such as tea, onions and apples. Data from several prospective studies indicate an inverse association of dietary flavonoids with coronary heart disease 34, However, confounding may be a major problem and may explain the conflicting results of observational studies.
High blood pressure is a major risk factor for coronary heart disease and both forms of stroke ischaemic and haemorrhagic. Of the many risk factors associated with high blood pressure, the dietary exposure that has been most investigated is daily sodium intake. It has been studied extensively in animal experimental models, in epidemiological studies, controlled clinical trials and in population studies on restricted sodium intake 36, All these data show convincingly that sodium intake is directly associated with blood pressure.
An overview of observational data obtained from population studies suggested that a difference in sodium intake of mmol per day was associated with average differences in systolic blood pressure of 5 mmHg at age years and 10 mmHg at age years Diastolic blood pressures are reduced by about half as much, but the association increases with age and magnitude of the initial blood pressure.
The first prospective study using hour urine collections for measuring sodium intake, which is the only reliable measure, demonstrated a positive relationship between an increased risk of acute coronary events, but not stroke events, and increased sodium excretion The association was strongest among overweight men.
Several clinical intervention trials, conducted to evaluate the effects of dietary salt reduction on blood pressure levels, have been systematically reviewed 39, Clinical trials have also demonstrated the sustainable blood pressure lowering effects of sodium restriction in infancy 41, 42 , as well as in the elderly in whom it provides a useful nonpharmacological therapy The results of a low-sodium diet trial 44 showed that low-sodium diets, with hour sodium excretion levels around 70 mmol, are effective and safe.
Two population studies, in China and in Portugal, have also revealed significant reductions in blood pressure in the intervention groups 45, Several large cohort studies have found an inverse association between potassium intake and risk of stroke 48, While potassium supplements have been shown to have protective effects on blood pressure and cardiovascular diseases, there is no evidence to suggest that long-term potassium supplements should be administered to reduce the risk for CVD.
The recommended levels of fruit and vegetable consumption assure an adequate intake of potassium. While the consumption of fruits and vegetables has been widely believed to promote good health, evidence related to their protective effect against CVD has only been presented in recent years Numerous ecological and prospective studies have reported a significant protective association for coronary heart disease and stroke with consumption of fruits and vegetables The effects of increased fruit and vegetable consumption on blood pressure alone and in combination with a low-fat diet, were assessed in the Dietary Approaches to Stop Hypertension DASH trial While the combination diet was more effective in lowering blood pressure, the fruit and vegetable diet also lowered blood pressure by 2.
Such reductions, while seeming modest at the individual level, would result in a substantial reduction in population-wide risk of CVD by shifting the blood pressure distribution. Most, but not all, population studies have shown that fish consumption is associated with a reduced risk of coronary heart disease.
A systematic review concluded that the discrepancy in the findings may be a result of differences in the populations studied, with only high-risk individuals benefiting from increasing their fish consumption A recent study based on data from 36 countries, reported that fish consumption is associated with a reduced risk of death from all causes as well as CVD mortality Several large epidemiological studies have demonstrated that frequent consumption of nuts was associated with decreased risk of coronary heart disease 58, Most of these studies considered nuts as a group, combining many different types of nuts.
Nuts are high in unsaturated fatty acids and low in saturated fats, and contribute to cholesterol lowering by altering the fatty acid profile of the diet as a whole. However, because of the high energy content of nuts, advice to include them in the diet must be tempered in accordance with the desired energy balance.
Several trials indicate that soy has a beneficial effect on plasma lipids 60, Soy is rich in isoflavones, compounds that are structurally and functionally similar to estrogen. Several animal experiments suggest that the intake of these isoflavones may provide protection against coronary heart disease, but human data on efficacy and safety are still awaited.
There is convincing evidence that low to moderate alcohol consumption lowers the risk of coronary heart disease. In a systematic review of ecological, case-control and cohort studies in which specific associations were available between risk of coronary heart-disease and consumption of beer, wine and spirits, it was found that all alcoholic drinks are linked with lower risk However, other cardiovascular and health risks associated with alcohol do not favour a general recommendation for its use.
Boiled, unfiltered coffee raises total and LDL cholesterol because coffee beans contain a terpenoid lipid called cafestol. The amount of cafestol in the cup depends on the brewing method: Intake of large amounts of unfiltered coffee markedly raises serum cholesterol and has been associated with coronary heart disease in Norway A shift from unfiltered, boiled coffee to filtered coffee has contributed significantly to the decline in serum cholesterol in Finland Measures aimed at reducing the risk of CVD are outlined below.
The strength of evidence on lifestyle factors is summarized in Table Dietary intake of fats strongly influences the risk of cardiovascular diseases such as coronary heart disease and stroke, through effects on blood lipids, thrombosis, blood pressure, arterial endothelial function, arrythmogenesis and inflammation.
However, the qualitative composition of fats in the diet has a significant role to play in modifying this risk. Summary of strength of evidence on lifestyle factors and risk of developing cardiovascular diseases. Myristic and palmitic acids Trans fatty acids High sodium intake Overweight High alcohol intake for stroke. Fats rich in lauric acid Impaired fetal nutrition Beta-carotene supplements.
The evidence shows that intake of saturated fatty acids is directly related to cardiovascular risk. Within these limits, intake of foods rich in myristic and palmitic acids should be replaced by fats with a lower content of these particular fatty acids. The amount and quality of fat supply has to be considered keeping in mind the need to meet energy requirements.
Specific sources of saturated fat, such as coconut and palm oil, provide low-cost energy and may be an important source of energy for the poor. Not all saturated fats have similar metabolic effects; those with carbons in the fatty acid chain have a greater effect on raising LDL cholesterol.
This implies that the fatty acid composition of the fat source should be examined. As populations progress in the nutrition transition and energy excess becomes a potential problem, restricting certain fatty acids becomes progressively more relevant to ensuring cardiovascular health.
To promote cardiovascular health, diets should provide a very low intake of trans fatty acids hydrogenated oils and fats. This recommendation is especially relevant in developing countries where low-cost hydrogenated fat is frequently consumed.
The potential effect of human consumption of hydrogenated oils of unknown physiological effects e. Diets should provide an adequate intake of PUFAs, i. Recommendations for total fat intake may be based on current levels of population consumption in different regions and modified to take account of age, activity and ideal body weight.
Where obesity is prevalent, for example, an intake in the lower part of the range is preferable in order to achieve a lower energy intake. While there is no evidence to directly link the quantity of daily fat intake to an increased risk of CVD, total fat consumption should be limited to enable the goals of reduced intake of saturated and trans fatty acids to be met easily in most populations and to avoid the potential problems of undesirable weight gain that may arise from unrestricted fat intake.
These dietary goals can be met by limiting the intake of fat from dairy and meat sources, avoiding the use of hydrogenated oils and fats in cooking and manufacture of food products, using appropriate edible vegetable oils in small amounts, and ensuring a regular intake of fish one to two times per week or plant sources of a-linolenic acid.
Preference should be given to food preparation practices that employ non-frying methods. Fruits and vegetables contribute to cardiovascular health through the variety of phytonutrients, potassium and fibre that they contain. Daily intake of fresh fruit and vegetables including berries, green leafy and cruciferous vegetables and legumes , in an adequate quantity g per day , is recommended to reduce the risk of coronary heart disease, stroke and high blood pressure.
Dietary intake of sodium, from all sources, influences blood pressure levels in populations and should be limited so as to reduce the risk of coronary heart disease and both forms of stroke. Current evidence suggests that an intake of no more than 70 mmol or 1. The special situation of individuals i. Limitation of dietary sodium intake to meet these goals should be achieved by restricting daily salt sodium chloride intake to less than 5 g per day.
This should take into account total sodium intake from all dietary sources, for example additives such as monosodium glutamate and preservatives. Use of potassium-enriched low-sodium substitutes is one way to reduce sodium intake.
Adequate dietary intake of potassium lowers blood pressure and is protective against stroke and cardiac arrythmias. Potassium intake should be at a level which will keep the sodium to potassium ratio close to 1. This may be achieved through adequate daily consumption of fruits and vegetables. Fibre is protective against coronary heart disease and has also been used in diets to lower blood pressure. Adequate intake may be achieved through fruits, vegetables and wholegrain cereals.
Regular fish consumption servings per week is protective against coronary heart disease and ischaemic stroke and is recommended.
The serving should provide an equivalent of mg of eicosapentaenoic and docosahexaenoic acid. People who are vegetarians are recommended to ensure adequate intake of plant sources of a-linolenic acid. Although regular low to moderate consumption of alcohol is protective against coronary heart disease, other cardiovascular and health risks associated with alcohol do not favour a general recommendation for its use.
Physical activity is related to the risk of cardiovascular diseases, especially coronary heart disease, in a consistent inverse dose-response fashion when either volume or intensity are used for assessment. These relationships apply to both incidence and mortality rates from all cardiovascular diseases and from coronary heart disease.
At present, no consistent dose-response relationship can be found between risk of stroke and physical activity. The lower limits of volume or intensity of the protective dose of physical activity have not been defined with certainty, but the current recommendation of at least 30 minutes of at least moderate-intensity physical activity on most days of the week is considered sufficient.
A higher volume or intensity of activity would confer a greater protective effect. The recommended amount of physical activity is sufficient to raise cardiorespiratory fitness to the level that has been shown to be related to decreased risk of cardiovascular disease.
Individuals who are unaccustomed to regular exercise or have a high-risk profile for CVD should avoid sudden and high-intensity bursts of physical activity. Cardiovascular diseases in the developing countries: Public Health Nutrition , , 5: Kris-Etherton PM et al. Summary of the scientific conference on dietary fatty acids and cardiovascular health: Circulation , , Plasma cholesterol responsiveness to saturated fatty acids. Dietary oils, serum lipoproteins and coronary heart disease.
American Journal of Clinical Nutrition , , 61 Suppl. Effect of dietary fatty acids on serum lipids and lipoproteins. A meta-analysis of 27 trials. Arteriosclerosis and Thrombosis , , Hu FB et al. Dietary fat intake and the risk of coronary heart disease in women. Trans fatty acids and plasma lipoproteins. Oomen CM et al. Association between trans fatty acid intake and year risk of coronary heart disease in the Zutphen Elderly Study: Willett WC et al.
Intake of trans fatty acids and risk of coronary heart disease among women. Monosaturated fatty acids and risk of cardiovascular disease. Long-chain omega 3 fatty acids, blood lipids and cardiovascular risk reduction. Current Opinion in Lipidology , , Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: Fish and omega-3 fatty acid intake and risk of coronary heart disease in women.
Ascherio A et al. Dietary fat and risk of coronary heart disease in men: Effects of dietary cholesterol on serum cholesterol: A prospective study of egg consumption and risk of cardiovascular disease in men and women. Miettinen TA et al. Reduction of serum cholesterol with sitostanol-ester margarine in a mildly hypercholesterolemic population.
Plant sterols and stanol margarines and health. Impact of nondigestible carbohydrates on serum lipoproteins and risk for cardiovascular disease. Journal of Nutrition , , Cereal grains and coronary heart disease. Liu S et al. Whole-grain consumption and risk of coronary heart disease: Pietinen P et al. Intake of dietary fiber and risk of coronary heart disease in a cohort of Finnish men. Rimm EB et al. Vegetable, fruit, and cereal fiber intake and risk of coronary heart disease among men.
Yusuf S et al. Vitamin E supplementation and cardiovascular events in high-risk patients. Heart Protection Study Collaborative Group. Meta-analysis of observational studies.
Brouwer IA et al. Low dose folic acid supplementation decreases plasma homocysteine concentrations: Ueland PM et al.
The controversy over homocysteine and cardiovascular risk. Nygard O et al. Total plasma homocysteine and cardiovascular risk profile. The Hordaland Homocysteine Study. Homocysteine and cardiovascular disease: Guttormsen AB et al. Kinetic basis of hyperhomocysteinemia in patients with chronic renal failure. Kidney International , , Folate and vitamin B6 from diet and supplements in relation to risk of coronary heart disease among women. British Medical Journal, Keli SO et al.
Dietary flavonoids, antioxidant vitamins, and incidence of stroke: Archives of Internal Medicine , Hertog MGL et al. Dietary antioxidant flavonoids and risk of coronary heart disease: Salt and cardiovascular disease: Journal of Cardiovascular Risk , , 7: By how much does salt reduction lower blood pressure?
III-Analysis of data from trials of salt reduction. Urinary sodium excretion and cardiovascular mortality in Finland: Randomized trials of sodium reduction: Midgley JP et al. Effect of reduced dietary sodium on blood pressure: Geleijnse JM et al.
Long-term effects of neonatal sodium restriction on blood pressure. Hypertension , , A randomized trial of sodium intake and blood pressure in newborn infants. Whelton PK et al. Sodium reduction and weight loss in the treatment of hypertension in older persons.
Sacks FM et al. Forte JG et al. Salt and blood pressure: Journal of Human Hypertension , , 3: Tian HG et al. Changes in sodium intake and blood pressure in a community-based intervention project in China. Journal of Human Hypertension , , 9: Effects of oral potassium on blood pressure.
Meta-analysis of randomized controlled clinical trials. Intake of potassium, magnesium, and fiber and risk of stroke among US men. Dietary potassium and stroke-associated mortality. Ayear prospective population study. Fruit and vegetables, and cardiovascular disease: Fruit and vegetable intake and risk of cardiovascular disease: Joshipura KJ et al. Fruit and vegetable intake in relation to risk of ischemic stroke. Gilman MW et al. Protective effect of fruits and vegetables on development of stroke in men.
Appel LJ et al. A clinical trial of the effects of dietary patterns on blood pressure. Marckmann P, Gronbaek M.
Fish consumption and coronary heart disease mortality. A systematic review of prospective cohort studies. Burr ML et al. Effects of changes in fat, fish and fibre intakes on death and myocardial reinfarction: Lancet , , 2: Zhang J et al. Fish consumption and mortality from all causes, ischemic heart disease, and stroke: Preventive Medicine , , The effects of nuts on coronary heart disease risk. Nut consumption and risk of coronary heart disease: Current Atherosclerosis Reports , , 1: Journal of Nutrition , , Suppl.
Crouse JR et al. Randomized trial comparing the effect of casein with that of soy protein containing varying amounts of isoflavones on plasma concentrations of lipids and lipoproteins. Archives of Internal Medicine , , Cardiovascular and renal benefits of dry bean and soybean intake. Moderate alcohol intake and lower risk of coronary heart disease: Tverdal A et al. Coffee consumption and death from coronary heart disease in middle-aged Norwegian men and women.
Changes in diet in Finland from to Cancer is caused by a variety of identified and unidentified factors. The most important established cause of cancer is tobacco smoking. Other important determinants of cancer risk include diet, alcohol and physical activity, infections, hormonal factors and radiation. The relative importance of cancers as a cause of death is increasing, mostly because of the increasing proportion of people who are old, and also in part because of reductions in mortality from some other causes, especially infectious diseases.
The incidence of cancers of the lung, colon and rectum, breast and prostate generally increases in parallel with economic development, while the incidence of stomach cancer usually declines with development.
Cancer is now a major cause of mortality throughout the world and, in the developed world, is generally exceeded only by cardiovascular diseases. An estimated 10 million new cases and over 6 million deaths from cancer occurred in 1. As developing countries become urbanized, patterns of cancer, including those most strongly associated with diet, tend to shift towards those of economically developed countries.
Cancer rates change as populations move between countries and adopt different dietary and other behaviours, further implicating dietary factors in the etiology of cancer. Body weight and physical inactivity together are estimated to account for approximately one-fifth to one-third of several of the most common cancers, specifically cancers of the breast postmenopausal , colon, endometrium, kidney and oesophagus adenocarcinoma 4.
Research to date has uncovered few definite relationships between diet and cancer risk. Dietary factors for which there is convincing evidence for an increase in risk are overweight and obesity, and a high consumption of alcoholic beverages, aflatoxins, and some forms of salting and fermenting fish.
There is also convincing evidence to indicate that physical activity decreases the risk of colon cancer. Factors which probably increase risk include high dietary intake of preserved meats, salt-preserved foods and salt, and very hot thermally drinks and food.
Probable protective factors are consumption of fruits and vegetables, and physical activity for breast cancer. After tobacco, overweight and obesity appear to be the most important known avoidable causes of cancer. Cancers of the oral cavity, pharynx and oesophagus. Overweight and obesity are established risk factors specifically for adenocarcinoma but not squamous cell carcinoma of the oesophagus The relative roles of various micronutrients are not yet clear 5, 9. There is also consistent evidence that consuming drinks and foods at a very high temperature increases the risk for these cancers Nasopharyngeal cancer is particularly common in South-East Asia 11 , and has been clearly associated with a high intake of Chinese-style salted fish, especially during early childhood 12, 13 , as well as with infection with the Epstein-Barr virus 2.
Until about 20 years ago stomach cancer was the most common cancer in the world, but mortality rates have been falling in all industrialized countries 14 and stomach cancer is currently much more common in Asia than in North America or Europe Infection with the bacterium Helicobacter pylori is an established risk factor, but not a sufficient cause, for the development of stomach cancer Diet is thought to be important in the etiology of this disease; substantial evidence suggests that risk is increased by high intakes of some traditionally preserved salted foods, especially meats and pickles, and with salt per se, and that risk is decreased by high intakes of fruits and vegetables 16 , perhaps because of their vitamin C content.
Further prospective data are needed, in particular to examine whether some of the dietary associations may be partly confounded by Helicobacter pylori infection and whether dietary factors may modify the association of Helicobacter pylori with risk. These factors together, however, do not explain the large variation between populations in colorectal cancer rates. International correlation studies have shown a strong association between per capita consumption of meat and colorectal cancer mortality 19 , and a recent systematic review concluded that preserved meat is associated with an increased risk for colorectal cancer but that fresh meat is not However, most studies have not observed positive associations with poultry or fish 9.
Overall, the evidence suggests that high consumption of preserved and red meat probably increases the risk for colorectal cancer. As with meat, international correlation studies show a strong association between per capita consumption of fat and colorectal cancer mortality However, the results of observational studies of fat and colorectal cancer have, overall, not been supportive of an association with fat intake 9, Furthermore, results from randomized controlled trials have not shown that intervention over a year period with supplemental fibre or a diet low in fat and high in fibre and fruits and vegetables can reduce the recurrence of colorectal adenomas It is possible that some of the inconsistencies are a result of differences between studies in the types of fibre eaten and in the methods for classifying fibre in food tables, or that the association with fruits and vegetables arises principally from an increase in risk at very low levels of consumption On balance, the evidence that is currently available suggests that intake of fruits and vegetables probably reduces the risk for colorectal cancer.
Recent studies have suggested that vitamins and minerals might influence the risk for colorectal cancer. Some prospective studies have suggested that a high intake of folate from diet or vitamin supplements is associated with a reduced risk for colon cancer Another promising hypothesis is that relatively high intakes of calcium may reduce the risk for colorectal cancer; several observational studies have supported this hypothesis 9, 34 , and two trials have indicated that supplemental calcium may have a modest protective effect on the recurrence of colorectal adenomas 29, The major risk factor for hepatocellular carcinoma, the main type of liver cancer, is chronic infection with hepatitis B, and to a lesser extent, hepatitis C virus Ingestion of foods contaminated with the mycotoxin, aflatoxin is an important risk factor among people in developing countries, together with active hepatitis virus infection 13, Excessive alcohol consumption is the main diet-related risk factor for liver cancer in industrialized countries, probably via the development of cirrhosis and alcoholic hepatitis 5.
Cancer of the pancreas is more common in industrialized countries than in developing countries 11, Overweight and obesity possibly increase the risk 9, Some studies have suggested that risk is increased by high intakes of meat, and reduced by high intakes of vegetables, but these data are not consistent 9.
Lung cancer is the most common cancer in the world Numerous observational studies have found that lung cancer patients typically report a lower intake of fruits, vegetables and related nutrients such as b-carotene than controls 9, The only one of these factors to have been tested in controlled trials, namely b-carotene, has, however, failed to produce any benefit when given as a supplement for up to 12 years The possible effect of diet on lung cancer risk remains controversial, and the apparent protective effect of fruits and vegetables may be largely the result of residual confounding by smoking, since smokers generally consume less fruit and vegetables than non-smokers.
In public health terms, the overriding priority for preventing lung cancer is to reduce the prevalence of smoking. Breast cancer is the second most common cancer in the world and the most common cancer among women. Incidence rates are about five times higher in industrialized countries than in less developed countries and Japan Much of this international variation is a result of differences in established reproductive risk factors such as age at menarche, parity and age at births, and breastfeeding 43, 44 , but differences in dietary habits and physical activity may also contribute.
In fact, age at menarche is partly determined by dietary factors, in that restricted dietary intake during childhood and adolescence leads to delayed menarche. Adult height, also, is weakly positively associated with risk, and is partly determined by dietary factors during childhood and adolescence Estradiol and perhaps other hormones play a key role in the etiology of breast cancer 43 , and it is possible that any further dietary effects on risk are mediated by hormonal mechanisms.
The only dietary factors which have been shown to increase the risk for breast cancer are obesity and alcohol. Obesity does not increase risk among premenopausal women, but obesity in premenopausal women is likely to lead to obesity throughout life and therefore to an eventual increase in breast cancer risk. The mechanism for this association is not known, but may involve increases in estrogen levels The results of studies of other dietary factors including fat, meat, dairy products, fruits and vegetables, fibre and phyto-estrogens are inconclusive 9, 34, 47, Endometrial cancer risk is about three-fold higher in obese women than in lean women 8, 49 , probably because of the effects of obesity on hormone levels Some case-control studies have suggested that diets high in fruits and vegetables may reduce risk and that diets high in saturated or total fat may increase risk, but the amount of available data is limited 9.
Prostate cancer incidence rates are strongly affected by diagnostic practices and therefore difficult to interpret, but mortality rates show that death from prostate cancer is about 10 times more common in North America and Europe than in Asia The data from prospective studies have not established causal or protective associations for specific nutrients or dietary factors 9, Diets high in red meat, dairy products and animal fat have frequently been implicated in the development of prostate cancer, although the data are not entirely consistent 9, Randomized controlled trials have provided substantial, consistent evidence that supplements of b-carotene do not alter the risk for prostate cancer 40, 41, 54 but have suggested that vitamin E 54 and selenium 55 might have a protective effect.
Lycopene, primarily from tomatoes, has been associated with a reduced risk in some observational studies, but the data are not consistent Hormones control the growth of the prostate, and diet might influence prostate cancer risk by affecting hormone levels.
Table 11 provides a summary of strength of evidence with regard to the role of various risk factors in the development of cancer. Summary of strength of evidence on lifestyle factors and the risk of developing cancer. Overweight and obesity oesophagus, colorectum, breast in postmenopausal women, endometrium, kidney Alcohol oral cavity, pharynx, larynx, oesophagus, liver, breast Aflatoxin liver Chinese-style salted fish nasopharynx.
Fruits and vegetables oral cavity, oesophagus, stomach, colorectum b Physical activity breast. Preserved meat colorectum Salt-preserved foods and salt stomach Very hot thermally drinks and food oral cavity, pharynx, oesophagus. Animal fats Heterocyclic amines Polycyclic aromatic hydrocarbons Nitrosamines.
The Consultation recognized the problems posed by the lack of data on diet and cancer from the developing world. There are very limited data from Africa, Asia and Latin America, yet these regions represent two-thirds or more of the world population. There is thus an urgent need for epidemiological research on diet and cancer in these regions. The need to evaluate the role of food processing methods, traditional and industrial, was also identified. Microbiological and chemical food contaminants may also contribute to carcinogenicity of diets.
The nutrition transition is accompanied by changes in prevalence of specific cancers. For some cancers, such as stomach cancer, this may be beneficial while for others, such as colorectal and breast cancers, the changes are adverse. Maintain weight among adults such that BMI is in the range of Maintain regular physical activity.
The primary goal should be to perform physical activity on most days of the week; 60 minutes per day of moderate-intensity activity, such as walking, may be needed to maintain healthy body weight in otherwise sedentary people. More vigorous activity, such as fast walking, may give some additional benefits for cancer prevention 4. Consumption of alcoholic beverages is not recommended: Chinese-style fermented salted fish should only be consumed in moderation, especially during childhood.
Overall consumption of salt-preserved foods and salt should be moderate. Those who are not vegetarian are advised to moderate consumption of preserved meat e. Global cancer statistics in the year Lancet Oncology , , 2: Doll R, Peto R. Oxford textbook of medicine. Oxford, Oxford University Press, Diet, nutrition, and avoidable cancer.
Environmental Health Perspectives , , Suppl. Brown LM et al. Adenocarcinoma of the esophagus: Journal of the National Cancer Institute , , Cheng KK et al. A case-control study of oesophageal adenocarcinoma in women: British Journal of Cancer , , Overweight and lack of exercise linked to increased cancer risk.
Sharp L et al. Risk factors for squamous cell carcinoma of the oesophagus in women: Ferlay J et al. Relevance to human cancer of N-nitroso compounds, tobacco smoke and mycotoxins. Lyon, International Agency for Research on Cancer, Some naturally occurring substances: World health statistics annual.
Geneva, World Health Organization, available on the Internet at http: Helicobacter and Cancer Collaborative Group.
Gastric cancer and Helicobacter pylori: Gut , , Epidemiology of gastric cancer: Journal of Gastroenterology , , 35 Suppl. Diet and the prevention of cancer. Physical activity and cancer risk. Proceedings of the Nutrition Society , , Armstrong B, Doll R. Environmental factors and cancer incidence and mortality in different countries, with special reference to dietary practices. International Journal of Cancer , , Norat T et al. Meat consumption and colorectal cancer risk: Howe GR et al.
The relationship between dietary fat intake and risk of colorectal cancer: Cancer Causes and Control , , 8: Potter JD, Steinmetz K. Vegetables, fruit and phytoestrogens as preventive agents. Jacobs DR Jr et al. Whole-grain intake and cancer: Nutrition and Cancer , , Plant foods and the risk of colorectal cancer in Europe: Riboli E, Lambert R, eds.
Fuchs CS et al. Dietary fiber and the risk of colorectal cancer and adenoma in women. Michels KB et al. Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers. Will you take two minutes to complete a brief survey that will help us to improve our website? Thank you for agreeing to provide feedback on the new version of worldbank. Thank you for participating in this survey!
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