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Objective: Vegetarians and vegans exclude certain food sources of vitamin D from their diet, but it is not clear to what extent this affects plasma concentrations of 25-hydroxyvitamin D (25(OH)D). The objective was to investigate differences in vitamin D intake and plasma concentrations of 25(OH)D among meat eaters, fish eaters, vegetarians and vegans.Design: A cross-sectional analysis.Setting: United Kingdom.Subjects: Plasma 25(OH)D concentrations were measured in 2107 white men and women (1388 meat eaters, 210 fish eaters, 420 vegetarians and eighty-nine vegans) aged 20-76 years from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Oxford cohort.Results: Plasma 25(OH)D concentrations reflected the degree of animal product exclusion and, hence, dietary intake of vitamin D; meat eaters had the highest mean intake of vitamin D (3·1 (95 % CI 3·0, 3·2) μg/d) and mean plasma 25(OH)D concentrations (77·0 (95 % CI 75·4, 78·8) nmol/l) and vegans the lowest (0·7 (95 % CI 0·6, 0·8) μg/d and 55·8 (95 % CI 51·0, 61·0) nmol/l, respectively). The magnitude of difference in 25(OH)D concentrations between meat eaters and vegans was smaller (20 %) among those participants who had a blood sample collected during the summer months (July-September) compared with the winter months (38 %; January-March). The prevalence of low plasma concentrations of 25(OH)D (<25 nmol/l) during the winter and spring ranged from <1 % to 8 % across the diet groups.Conclusions: Plasma 25(OH)D concentrations were lower in vegetarians and vegans than in meat and fish eaters; diet is an important determinant of plasma 25(OH)D in this British population. [ABSTRACT FROM AUTHOR]

Objective: The risk factors for fractures are incompletely understood. An outstanding question concerns the optimal amount of dietary calcium needed to minimise the risk of fracture.Design: We examined the associations of dietary calcium and other nutrients with self-reported fracture risk in a prospective cohort study. Nutrient intakes were estimated using a semi-quantitative food-frequency questionnaire administered at recruitment.Setting: The UK.Participants: A total of 26 749 women and 7947 men aged 20-89 years.Results: Over an average of 5.2 years of follow-up, 1555 women and 343 men reported one or more fractures, 72% of these resulting from a fall. Among women, fracture risk was higher at lower calcium intakes, with a relative risk of 1.75 (95% confidence interval (CI) 1.33-2.29) among women with a calcium intake of < 525 mg day- 1 compared with women with a calcium intake of at least 1200 mg day- 1 (test for linear trend, P < 0.001). The association of dietary calcium with fracture risk was stronger among women aged under 50 years at recruitment than among women aged 50 and above. Dietary calcium intake was not associated with fracture risk in men. Fracture risk was not related to the dietary intake of any other nutrient examined.Conclusion: In this population, women with a low dietary calcium intake had an increased risk of bone fracture, and this association was more marked among younger women than among older women. [ABSTRACT FROM AUTHOR]

Objective: To assess the epidemiological evidence on diet and cancer and make public health recommendations.Design: Review of published studies, concentrating on recent systematic reviews, meta-analyses and large prospective studies.Conclusions and Recommendations: Overweight/obesity increases the risk for cancers of the oesophagus (adenocarcinoma), colorectum, breast (postmenopausal), endometrium and kidney; body weight should be maintained in the body mass index range of 18.5-25 kg/m(2), and weight gain in adulthood avoided. Alcohol causes cancers of the oral cavity, pharynx, oesophagus and liver, and a small increase in the risk for breast cancer; if consumed, alcohol intake should not exceed 2 units/d. Aflatoxin in foods causes liver cancer, although its importance in the absence of hepatitis virus infections is not clear; exposure to aflatoxin in foods should be minimised. Chinese-style salted fish increases the risk for nasopharyngeal cancer, particularly if eaten during childhood, and should be eaten only in moderation. Fruits and vegetables probably reduce the risk for cancers of the oral cavity, oesophagus, stomach and colorectum, and diets should include at least 400 g/d of total fruits and vegetables. Preserved meat and red meat probably increase the risk for colorectal cancer; if eaten, consumption of these foods should be moderate. Salt preserved foods and high salt intake probably increase the risk for stomach cancer; overall consumption of salt preserved foods and salt should be moderate. Very hot drinks and foods probably increase the risk for cancers of the oral cavity, pharynx and oesophagus; drinks and foods should not be consumed when they are scalding hot. Physical activity, the main determinant of energy expenditure, reduces the risk for colorectal cancer and probably reduces the risk for breast cancer; regular physical activity should be taken. [ABSTRACT FROM AUTHOR]

Objective: To describe the lifestyle characteristics and nutrient intakes of the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC).Design: Cohort of men and women recruited through general practices or by post to include a high proportion of non meat-eaters. Dietary, anthropometric and lifestyle data were collected at baseline and four diet groups were defined.Setting: United Kingdom.Participants: In total, 65 429 men and women aged 20 to 97 years, comprising 33 883 meat-eaters, 10 110 fish-eaters, 18 840 lacto-ovo vegetarians and 2596 vegans.Results: Nutrient intakes and lifestyle factors differed across the diet groups, with striking differences between meat-eaters and vegans, and fish-eaters and vegetarians usually having intermediate values. Mean fat intake in each diet group was below the UK dietary reference value of 33% of total energy intake. The mean intake of saturated fatty acids in vegans was approximately 5% of energy, less than half the mean intake among meat-eaters (10-11%). Vegans had the highest intakes of fibre, vitamin B1, folate, vitamin C, vitamin E, magnesium and iron, and the lowest intakes of retinol, vitamin B12, vitamin D, calcium and zinc.Conclusions: The EPIC-Oxford cohort includes 31 546 non meat-eaters and is one of the largest studies of vegetarians in the world. The average nutrient intakes in the whole cohort are close to those currently recommended for good health. Comparisons of the diet groups show wide ranges in the intakes of major nutrients such as saturated fat and dietary fibre. Such variation should increase the ability of the study to detect associations of diet with major cancers and causes of death. [ABSTRACT FROM AUTHOR]

Energy balance can affect the risk for hormone-related cancers by altering sex hormone levels. Energy intake and expenditure are difficult to measure in epidemiological studies, but a chronic excess of intake relative to expenditure leads to a high BMI, which can be accurately measured. In premenopausal women obesity has little effect on the serum concentration of oestradiol, but causes an increase in the frequency of anovular menstrual cycles and thus a reduction in progesterone levels; these changes lead to a large increase in the risk for endometrial cancer. but little change, or a small decrease, in the risk for breast cancer. In post-menopausal women oestradiol levels are not regulated by negative feedback, and obesity causes an increase in the serum concentration of bioavailable oestradiol; this factor causes increases in the risk for both endometrial cancer and breast cancer. The development of ovarian cancer appears to be related more strongly to the frequency of ovulation than to direct effects of circulating levels of sex hormones, and BMI is not clearly associated with the risk for ovarian cancer. In men, increasing BMI has little effect on bioavailable androgen levels, and any effect of obesity on prostate cancer risk is small. [ABSTRACT FROM AUTHOR]

There is considerable epidemiological evidence that a Western-style diet may increase the risk of certain hormone-dependent conditions in men via its effects on hormone metabolism. Experimental evidence also suggests that dietary factors may exert subtle effects on hormone metabolism. Here we review the clinical and epidemiological evidence that diet is associated with circulating sex hormone levels in men. In comparison with factors such as age and BMI, nutrients do not appear to be strong determinants of sex hormone levels. Dietary intervention studies have not shown that a change in dietary fat and/or dietary fibre intake is associated with changes in circulating sex hormone concentrations over the short term. The data on the effects of dietary phyto-oestrogens on sex hormone levels in men are too limited for conclusions to be drawn. Observational studies between men from different dietary groups have shown that a vegan diet is associated with small but significant increases in sex-hormone-binding globulin and testosterone concentrations in comparison with meat-eaters. However, these studies have not demonstrated that variations in dietary composition have any long-term important effects on circulating bioavailable sex hormone levels in men. This lack of effect may be partly explained by the body's negative feedback mechanism, which balances out small changes in androgen metabolism in order to maintain a constant level of circulating bioavailable androgens. It appears, therefore, that future studies should look for dietary effects on the feedback mechanism itself, or on the metabolism of androgens within the target tissues. [ABSTRACT FROM AUTHOR]