The role of plasma microseminoprotein-beta in prostate cancer: an observational nested case-control and Mendelian randomization study in the European prospective investigation into cancer and nutrition.

BACKGROUND: Microseminoprotein-beta (MSP), a protein secreted by the prostate epithelium, may have a protective role in the development of prostate cancer. The only previous prospective study found a 2% reduced prostate cancer risk per unit increase in MSP. This work investigates the association of MSP with prostate cancer risk using observational and Mendelian randomization (MR) methods. PATIENTS AND METHODS: A nested case-control study was conducted with the European Prospective Investigation into Cancer and Nutrition (EPIC) with 1871 cases and 1871 matched controls. Conditional logistic regression analysis was used to investigate the association of pre-diagnostic circulating MSP with risk of incident prostate cancer overall and by tumour subtype. EPIC-derived estimates were combined with published data to calculate an MR estimate using two-sample inverse-variance method. RESULTS: Plasma MSP concentrations were inversely associated with prostate cancer risk after adjusting for total prostate-specific antigen concentration [odds ratio (OR) highest versus lowest fourth of MSP = 0.65, 95% confidence interval (CI) 0.51-0.84, Ptrend = 0.001]. No heterogeneity in this association was observed by tumour stage or histological grade. Plasma MSP concentrations were 66% lower in rs10993994 TT compared with CC homozygotes (per allele difference in MSP: 6.09 ng/ml, 95% CI 5.56-6.61, r2=0.42). MR analyses supported a potentially causal protective association of MSP with prostate cancer risk (OR per 1 ng/ml increase in MSP for MR: 0.96, 95% CI 0.95-0.97 versus EPIC observational: 0.98, 95% CI 0.97-0.99). Limitations include lack of complete tumour subtype information and more complete information on the biological function of MSP. CONCLUSIONS: In this large prospective European study and using MR analyses, men with high circulating MSP concentration have a lower risk of prostate cancer. MSP may play a causally protective role in prostate cancer.

Sex hormones and risk of breast cancer in premenopausal women: a collaborative reanalysis of individual participant data from seven prospective studies.

BACKGROUND: Associations between circulating concentrations of oestrogens, progesterone, and androgens with breast cancer and related risk factors in premenopausal women are not well understood. We aimed to characterise these associations with a pooled analysis of data from seven studies. METHODS: Individual participant data for prediagnostic sex hormone and sex hormone-binding globulin (SHBG) concentrations were contributed from seven prospective studies. We restricted analyses to women who were premenopausal and younger than 50 years at blood collection, and to women with breast cancer diagnosed before age 50 years. We estimated odds ratios (ORs) with 95% CIs for breast cancer associated with hormone concentrations by conditional logistic regression in cases and controls matched for age, date of blood collection, and day of cycle, with stratification by study and further adjustment for cycle phase. We examined associations of hormones with risk factors for breast cancer in control women by comparing geometric mean hormone concentrations in categories of these risk factors, adjusted for study, age, phase of menstrual cycle, and body-mass index (BMI). All statistical tests were two-sided. FINDINGS: We included data for up to 767 women with breast cancer and 1699 controls in the risk analyses. Breast cancer risk was associated with a doubling in concentrations of oestradiol (OR 1·19, 95% CI 1·06-1·35), calculated free oestradiol (1·17, 1·03-1·33), oestrone (1·27, 1·05-1·54), androstenedione (1·30, 1·10-1·55), dehydroepiandrosterone sulphate (1·17, 1·04-1·32), testosterone (1·18, 1·03-1·35), and calculated free testosterone (1·08, 0·97-1·21). Breast cancer risk was not associated with luteal phase progesterone (doubling in concentration OR 1·00, 95% CI 0·92-1·09), and adjustment for other factors had little effect on any of these ORs. Cross-sectional analyses in control women showed several associations of sex hormones with breast cancer risk factors. INTERPRETATION: Circulating oestrogens and androgens are positively associated with the risk for breast cancer in premenopausal women.

Circulating sex hormones and breast cancer risk factors in postmenopausal women: reanalysis of 13 studies.

BACKGROUND: Breast cancer risk for postmenopausal women is positively associated with circulating concentrations of oestrogens and androgens, but the determinants of these hormones are not well understood. METHODS: Cross-sectional analyses of breast cancer risk factors and circulating hormone concentrations in more than 6000 postmenopausal women controls in 13 prospective studies. RESULTS: Concentrations of all hormones were lower in older than younger women, with the largest difference for dehydroepiandrosterone sulphate (DHEAS), whereas sex hormone-binding globulin (SHBG) was higher in the older women. Androgens were lower in women with bilateral ovariectomy than in naturally postmenopausal women, with the largest difference for free testosterone. All hormones were higher in obese than lean women, with the largest difference for free oestradiol, whereas SHBG was lower in obese women. Smokers of 15+ cigarettes per day had higher levels of all hormones than non-smokers, with the largest difference for testosterone. Drinkers of 20+ g alcohol per day had higher levels of all hormones, but lower SHBG, than non-drinkers, with the largest difference for DHEAS. Hormone concentrations were not strongly related to age at menarche, parity, age at first full-term pregnancy or family history of breast cancer. CONCLUSION: Sex hormone concentrations were strongly associated with several established or suspected risk factors for breast cancer, and may mediate the effects of these factors on breast cancer risk.

Cancer incidence in British vegetarians.

BACKGROUND: Few prospective studies have examined cancer incidence among vegetarians. METHODS: We studied 61,566 British men and women, comprising 32,403 meat eaters, 8562 non-meat eaters who did eat fish ('fish eaters') and 20,601 vegetarians. After an average follow-up of 12.2 years, there were 3350 incident cancers of which 2204 were among meat eaters, 317 among fish eaters and 829 among vegetarians. Relative risks (RRs) were estimated by Cox regression, stratified by sex and recruitment protocol and adjusted for age, smoking, alcohol, body mass index, physical activity level and, for women only, parity and oral contraceptive use. RESULTS: There was significant heterogeneity in cancer risk between groups for the following four cancer sites: stomach cancer, RRs (compared with meat eaters) of 0.29 (95% CI: 0.07-1.20) in fish eaters and 0.36 (0.16-0.78) in vegetarians, P for heterogeneity=0.007; ovarian cancer, RRs of 0.37 (0.18-0.77) in fish eaters and 0.69 (0.45-1.07) in vegetarians, P for heterogeneity=0.007; bladder cancer, RRs of 0.81 (0.36-1.81) in fish eaters and 0.47 (0.25-0.89) in vegetarians, P for heterogeneity=0.05; and cancers of the lymphatic and haematopoietic tissues, RRs of 0.85 (0.56-1.29) in fish eaters and 0.55 (0.39-0.78) in vegetarians, P for heterogeneity=0.002. The RRs for all malignant neoplasms were 0.82 (0.73-0.93) in fish eaters and 0.88 (0.81-0.96) in vegetarians (P for heterogeneity=0.001). CONCLUSION: The incidence of some cancers may be lower in fish eaters and vegetarians than in meat eaters.

Plasma phyto-oestrogens and prostate cancer in the European Prospective Investigation into Cancer and Nutrition.

We examined plasma concentrations of phyto-oestrogens in relation to risk for subsequent prostate cancer in a case-control study nested in the European Prospective Investigation into Cancer and Nutrition. Concentrations of isoflavones genistein, daidzein and equol, and that of lignans enterolactone and enterodiol, were measured in plasma samples for 950 prostate cancer cases and 1042 matched control participants. Relative risks (RRs) for prostate cancer in relation to plasma concentrations of these phyto-oestrogens were estimated by conditional logistic regression. Higher plasma concentrations of genistein were associated with lower risk of prostate cancer: RR among men in the highest vs the lowest fifth, 0.71 (95% confidence interval (CI) 0.53-0.96, P trend=0.03). After adjustment for potential confounders this RR was 0.74 (95% CI 0.54-1.00, P trend=0.05). No statistically significant associations were observed for circulating concentrations of daidzein, equol, enterolactone or enterodiol in relation to overall risk for prostate cancer. There was no evidence of heterogeneity in these results by age at blood collection or country of recruitment, nor by cancer stage or grade. These results suggest that higher concentrations of circulating genistein may reduce the risk of prostate cancer but do not support an association with plasma lignans.

Animal foods, protein, calcium and prostate cancer risk: the European Prospective Investigation into Cancer and Nutrition.

We examined consumption of animal foods, protein and calcium in relation to risk of prostate cancer among 142 251 men in the European Prospective Investigation into Cancer and Nutrition. Associations were examined using Cox regression, stratified by recruitment centre and adjusted for height, weight, education, marital status and energy intake. After an average of 8.7 years of follow-up, there were 2727 incident cases of prostate cancer, of which 1131 were known to be localised and 541 advanced-stage disease. A high intake of dairy protein was associated with an increased risk, with a hazard ratio for the top versus the bottom fifth of intake of 1.22 (95% confidence interval (CI): 1.07-1.41, P(trend)=0.02). After calibration to allow for measurement error, we estimated that a 35-g day(-1) increase in consumption of dairy protein was associated with an increase in the risk of prostate cancer of 32% (95% CI: 1-72%, P(trend)=0.04). Calcium from dairy products was also positively associated with risk, but not calcium from other foods. The results support the hypothesis that a high intake of protein or calcium from dairy products may increase the risk for prostate cancer.

Vegetarian diet as a risk factor for symptomatic gallstone disease.

BACKGROUND/OBJECTIVES: Previous small studies have shown either no difference or a lower risk of symptomatic gallstone disease in vegetarians than in non-vegetarians. This study examined the incidence of symptomatic gallstone disease in a cohort of British vegetarians and non-vegetarians, and investigated the associations between nutrient intake and risk of symptomatic gallstone disease. SUBJECTS/METHODS: The data were analysed from 49 652 adults enroled in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Oxford study, one-third of whom were vegetarian. The linked databases of hospital records were used to identify incident cases. Risk by diet group was estimated using Cox proportional hazards models. Further analysis quantified risk by intakes of selected macronutrients. RESULTS: There were 1182 cases of symptomatic gallstone disease during 687 822 person-years of follow-up (mean=13.85 years). There was a large significant association between increasing body mass index (BMI) and risk of developing symptomatic gallstone disease (overall trend P<0.001). After adjustment for BMI and other risk factors, vegetarians had a moderately increased risk compared with non-vegetarians (HR: 1.22; 95% CI: 1.06-1.41; P=0.006). Although starch consumption was positively associated with gallstones risk (P=0.002 for trend), it did not explain the increased risk in vegetarians. CONCLUSIONS: There is a highly significant association of increased BMI with risk of symptomatic gallstone disease. After adjusting for BMI, there is a small but statistically significant positive association between vegetarian diet and symptomatic gallstone disease.

Prostate cancer risk related to foods, food groups, macronutrients and micronutrients derived from the UK Dietary Cohort Consortium food diaries.

BACKGROUND/OBJECTIVES: The influence of dietary factors remains controversial for screen-detected prostate cancer and inconclusive for clinically detected disease. We aimed to examine these associations using prospectively collected food diaries. SUBJECTS/METHODS: A total of 1,717 prostate cancer cases in middle-aged and older UK men were pooled from four prospective cohorts with clinically detected disease (n=663), with routine data follow-up (means 6.6-13.3 years) and a case-control study with screen-detected disease (n=1054), nested in a randomised trial of prostate cancer treatments (ISCTRN 20141297). Multiple-day food diaries (records) completed by men prior to diagnosis were used to estimate intakes of 37 selected nutrients, food groups and items, including carbohydrate, fat, protein, dairy products, fish, meat, fruit and vegetables, energy, fibre, alcohol, lycopene and selenium. Cases were matched on age and diary date to at least one control within study (n=3528). Prostate cancer risk was calculated, using conditional logistic regression (adjusted for baseline covariates) and expressed as odds ratios in each quintile of intake (±95% confidence intervals). Prostate cancer risk was also investigated by localised or advanced stage and by cancer detection method. RESULTS: There were no strong associations between prostate cancer risk and 37 dietary factors. CONCLUSIONS: Prostate cancer risk, including by disease stage, was not strongly associated with dietary factors measured by food diaries in middle-aged and older UK men.

Plasma concentrations and intakes of amino acids in male meat-eaters, fish-eaters, vegetarians and vegans: a cross-sectional analysis in the EPIC-Oxford cohort.

BACKGROUND/OBJECTIVES: We aimed to investigate the differences in plasma concentrations and in intakes of amino acids between male meat-eaters, fish-eaters, vegetarians and vegans in the Oxford arm of the European Prospective Investigation into Cancer and Nutrition. SUBJECTS/METHODS: This cross-sectional analysis included 392 men, aged 30-49 years. Plasma amino acid concentrations were measured with a targeted metabolomic approach using mass spectrometry, and dietary intake was assessed using a food frequency questionnaire. Differences between diet groups in mean plasma concentrations and intakes of amino acids were examined using analysis of variance, controlling for potential confounding factors and multiple testing. RESULTS: In plasma, concentrations of 6 out of 21 amino acids varied significantly by diet group, with differences of -13% to +16% between meat-eaters and vegans. Concentrations of methionine, tryptophan and tyrosine were highest in fish-eaters and vegetarians, followed by meat-eaters, and lowest in vegans. A broadly similar pattern was seen for lysine, whereas alanine concentration was highest in fish-eaters and lowest in meat-eaters. For glycine, vegans had the highest concentration and meat-eaters the lowest. Intakes of all 18 dietary amino acids differed by diet group; for the majority of these, intake was highest in meat-eaters followed by fish-eaters, then vegetarians and lowest in vegans (up to 47% lower than in meat-eaters). CONCLUSIONS: Men belonging to different habitual diet groups have significantly different plasma concentrations of lysine, methionine, tryptophan, alanine, glycine and tyrosine. However, the differences in plasma concentrations were less marked than and did not necessarily mirror those seen for amino acid intakes.

Steroid hormone measurements from different types of assays in relation to body mass index and breast cancer risk in postmenopausal women: Reanalysis of eighteen prospective studies.

Epidemiological studies have examined breast cancer risk in relation to sex hormone concentrations measured by different methods: "extraction" immunoassays (with prior purification by organic solvent extraction, with or without column chromatography), "direct" immunoassays (no prior extraction or column chromatography), and more recently with mass spectrometry-based assays. We describe the associations of estradiol, estrone and testosterone with both body mass index and breast cancer risk in postmenopausal women according to assay method, using data from a collaborative pooled analysis of 18 prospective studies. In general, hormone concentrations were highest in studies that used direct assays and lowest in studies that used mass spectrometry-based assays. Estradiol and estrone were strongly positively associated with body mass index, regardless of the assay method; testosterone was positively associated with body mass index for direct assays, but less clearly for extraction assays, and there were few data for mass spectrometry assays. The correlations of estradiol with body mass index, estrone and testosterone were lower for direct assays than for extraction and mass spectrometry assays, suggesting that the estimates from the direct assays were less precise. For breast cancer risk, all three hormones were strongly positively associated with risk regardless of assay method (except for testosterone by mass spectrometry where there were few data), with no statistically significant differences in the trends, but differences may emerge as new data accumulate. Future epidemiological and clinical research studies should continue to use the most accurate assays that are feasible within the design characteristics of each study.

The Oxford Vegetarian Study: an overview.

The Oxford Vegetarian Study is a prospective study of 6000 vegetarians and 5000 nonvegetarian control subjects recruited in the United Kingdom between 1980 and 1984. Cross-sectional analyses of study data showed that vegans had lower total- and LDL-cholesterol concentrations than did meat eaters; vegetarians and fish eaters had intermediate and similar values. Meat and cheese consumption were positively associated, and dietary fiber intake was inversely associated, with total-cholesterol concentration in both men and women. After 12 y of follow-up, all-cause mortality in the whole cohort was roughly half that in the population of England and Wales (standardized mortality ratio, 0.46; 95% CI, 0.42, 0.51). After adjusting for smoking, body mass index, and social class, death rates were lower in non-meat-eaters than in meat eaters for each of the mortality endpoints studied [relative risks and 95% CIs: 0.80 (0. 65, 0.99) for all causes of death, 0.72 (0.47, 1.10) for ischemic heart disease, and 0.61 (0.44, 0.84) for all malignant neoplasms]. Mortality from ischemic heart disease was also positively associated with estimated intakes of total animal fat, saturated animal fat, and dietary cholesterol. Other analyses showed that non-meat-eaters had only half the risk of meat eaters of requiring an emergency appendectomy, and that vegans in Britain may be at risk for iodine deficiency. Thus, the health of vegetarians in this study is generally good and compares favorably with that of the nonvegetarian control subjects. Larger studies are needed to examine rates of specific cancers and other diseases among vegetarians.

Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies.

We combined data from 5 prospective studies to compare the death rates from common diseases of vegetarians with those of nonvegetarians with similar lifestyles. A summary of these results was reported previously; we report here more details of the findings. Data for 76172 men and women were available. Vegetarians were those who did not eat any meat or fish (n = 27808). Death rate ratios at ages 16-89 y were calculated by Poisson regression and all results were adjusted for age, sex, and smoking status. A random-effects model was used to calculate pooled estimates of effect for all studies combined. There were 8330 deaths after a mean of 10.6 y of follow-up. Mortality from ischemic heart disease was 24% lower in vegetarians than in nonvegetarians (death rate ratio: 0.76; 95% CI: 0.62, 0.94; P<0.01). The lower mortality from ischemic heart disease among vegetarians was greater at younger ages and was restricted to those who had followed their current diet for >5 y. Further categorization of diets showed that, in comparison with regular meat eaters, mortality from ischemic heart disease was 20% lower in occasional meat eaters, 34% lower in people who ate fish but not meat, 34% lower in lactoovovegetarians, and 26% lower in vegans. There were no significant differences between vegetarians and nonvegetarians in mortality from cerebrovascular disease, stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer, or all other causes combined.

Dietary determinants of ischaemic heart disease in health conscious individuals.

OBJECTIVE: To investigate dietary determinants of ischaemic heart disease (IHD) in health conscious individuals to explain the reduced risk in vegetarians, and to examine the relation between IHD and body mass index (BMI) within the normal range. DESIGN: Prospective observation of vegetarians, semi-vegetarians, and meat eaters for whom baseline dietary data, reported weight and height information, social class, and smoking habits were recorded. SUBJECTS: 10,802 men and women in the UK aged between 16 and 79, mean duration of follow up 13.3 years. MAIN OUTCOME MEASURES: Death rate rations for IHD and total mortality in relation to dietary and other characteristics recorded at recruitment (reference category death rate = 100). RESULTS: IHD mortality was less than half that expected from the experience reported for all of England and Wales. An increase in mortality for IHD was observed with increasing intakes of total and saturated animal fat and dietary cholesterol-death rate ratios in the third tertile compared with the first tertile: 329, 95% confidence interval (CI) 150 to 721; 277, 95% CI 125 to 613; 353, 95% CI 157 to 796, respectively. No protective effects were observed for dietary fibre, fish or alcohol. Within the study, death rate ratios were increased among those in the upper half of the normal BMI range (22.5 to < 25) and those who were overweight (BMI > or = 25) compared with those with BMI 20 to < 22.5. CONCLUSIONS: In these relatively health conscious individuals the deleterious effects of saturated animal fat and dietary cholesterol appear to be more important in the aetiology of IHD than the protective effect of dietary fibre. Reduced intakes of saturated animal fat and cholesterol may explain the lower rates of IHD among vegetarians compared with meat eaters. Increasing BMI within the normal range is associated with increased risk of IHD. The results have important public health implications.

Relation between body mass index and mortality in an unusually slim cohort.

STUDY OBJECTIVE: To investigate the relation between body mass index and mortality in an unusually slim cohort. DESIGN: Prospective cohort study. SETTING: United Kingdom. PARTICIPANTS: About 11,000 non-meat eaters and their meat eating friends and relatives, with a median age of 33 years were recruited between 1980 and 1984. More than 20% of the cohort had a self reported BMI below 20 kg/m(2) at recruitment. There were 195,000 person years of observation after a mean of 18.0 years of follow up. MAIN RESULTS: The characteristics of participants with a BMI below 18 kg/m(2) were favourable to a lower risk of cardiovascular disease. Nevertheless, these participants had an increased all cause death rate ratio (2.07, 95% CI 1.58 to 2.70) in comparison with participants who had a BMI between 20 and 22 kg/m(2). The death rate ratio for the slimmest category was also significantly increased for circulatory diseases (including ischaemic heart disease and cerebrovascular disease), respiratory diseases, and all other causes combined excluding all malignant neoplasms. This finding was consistent across a range of subgroups. CONCLUSIONS: Lean men and women (BMI <18 kg/m(2)) experience increased all cause mortality compared with those with a BMI between 20 and 22 kg/m(2). This pattern is not seen for cancer mortality, but is found for cardiovascular and respiratory diseases. It is important that public health messages regarding healthy eating are aimed at maintaining a healthy body weight rather than just "losing weight".

Dietary habits and mortality in 11,000 vegetarians and health conscious people: results of a 17 year follow up.

OBJECTIVE: To investigate the association of dietary habits with mortality in a cohort of vegetarians and other health conscious people. DESIGN: Observational study. SETTING: United Kingdom. SUBJECTS: 4336 men and 6435 women recruited through health food shops, vegetarian societies, and magazines. MAIN OUTCOME MEASURES: Mortality ratios for vegetarianism and for daily versus less than daily consumption of wholemeal bread, bran cereals, nuts or dried fruit, fresh fruit, and raw salad in relation to all cause mortality and mortality from ischaemic heart disease, cerebrovascular disease, all malignant neoplasms, lung cancer, colorectal cancer, and breast cancer. RESULTS: 2064 (19%) subjects smoked, 4627 (43%) were vegetarian, 6699 (62%) ate wholemeal bread daily, 2948 (27%) ate bran cereals daily, 4091 (38%) ate nuts or dried fruit daily, 8304 (77%) ate fresh fruit daily, and 4105 (38%) ate raw salad daily. After a mean of 16.8 years follow up there were 1343 deaths before age 80. Overall the cohort had a mortality about half that of the general population. Within the cohort, daily consumption of fresh fruit was associated with significantly reduced mortality from ischaemic heart disease (rate ratio adjusted for smoking 0.76 (95% confidence interval 0.60 to 0.97)), cerebrovascular disease (0.68 (0.47 to 0.98)), and for all causes combined (0.79 (0.70 to 0.90)). CONCLUSIONS: In this cohort of health conscious individuals, daily consumption of fresh fruit is associated with a reduced mortality from ischaemic heart disease, cerebrovascular disease, and all causes combined.

Serum concentrations of cholesterol, apolipoprotein A-I and apolipoprotein B in a total of 1694 meat-eaters, fish-eaters, vegetarians and vegans.

BACKGROUND/OBJECTIVES: The objective of this study was to describe serum lipid concentrations, including apolipoproteins A-I and B, in different diet groups. SUBJECTS/METHODS: A cross-sectional analysis of a sample of 424 meat-eaters, 425 fish-eaters, 423 vegetarians and 422 vegans, matched on sex and age, from the European Prospective Investigation into Cancer and Nutrition-Oxford cohort. Serum concentrations of total, and high-density lipoprotein (HDL) cholesterol, as well as apolipoproteins A-I and B were measured, and serum non-HDL cholesterol was calculated. RESULTS: Vegans had the lowest body mass index (BMI) and the highest and lowest intakes of polyunsaturated and saturated fat, respectively. After adjustment for age, alcohol and physical activity, compared with meat-eaters, fish-eaters and vegetarians, serum concentrations of total and non-HDL cholesterol and apolipoprotein B were significantly lower in vegans. Serum apolipoprotein A-I concentrations did not differ between the diet groups. In males, the mean serum total cholesterol concentration was 0.87 mmol/l lower in vegans than in meat-eaters; after further adjustment for BMI this difference was 0.76 mmol/l. In females, the difference in total cholesterol between these two groups was 0.6 mmol/l, and after further adjustment for BMI was 0.55 mmol/l. [corrected]. CONCLUSIONS: In this study, which included a large number of vegans, serum total cholesterol and apolipoprotein B concentrations were lower in vegans compared with meat-eaters, fish-eaters and vegetarians. A small proportion of the observed differences in serum lipid concentrations was explained by differences in BMI, but a large proportion is most likely due to diet.

Dietary fibre intake and ischaemic heart disease mortality: the European Prospective Investigation into Cancer and Nutrition-Heart study.

BACKGROUND/OBJECTIVES: Evidence from prospective studies is consistent in showing an inverse association between dietary fibre intake and risk of ischaemic heart disease (IHD), but whether dietary fibre from various food sources differ in their effect on IHD risk is less clear. The objective of this study was to assess the associations of total and food sources of dietary fibre with IHD mortality in the European Prospective Investigation into Cancer and Nutrition-Heart study. SUBJECTS/METHODS: Participants were 306,331 men and women from eight European countries. Dietary fibre intake was assessed using centre or country-specific diet questionnaires and calibrated using a 24-h diet recall. RESULTS: After an average follow-up of 11.5 years, there were 2381 IHD deaths among participants without cardiovascular disease at baseline. The calibrated intake of dietary fibre was inversely related with IHD mortality; each 10 g/day was associated with a 15% lower risk (relative risk (RR) 0.85; 95% confidence interval (CI): 0.73-0.99, P=0.031). There was no difference in the associations of the individual food sources of dietary fibre with the risk of IHD mortality; RR for each 5 g/day higher cereal fibre intake was 0.91 (CI: 0.82-1.01), RR for each 2.5 g/day fruit fibre intake was 0.94 (CI: 0.88-1.01) and RR for each 2.5 g/day vegetable fibre intake was 0.90 (95% CI: 0.76-1.07). CONCLUSION: A higher consumption of dietary fibre is associated with a lower risk of fatal IHD with no clear difference in the association with IHD for fibre from cereals, fruits or vegetables.

Serum concentrations of vitamin B12 and folate in British male omnivores, vegetarians and vegans: results from a cross-sectional analysis of the EPIC-Oxford cohort study.

BACKGROUND/OBJECTIVES: Vegans, and to a lesser extent vegetarians, have low average circulating concentrations of vitamin B12; however, the relation between factors such as age or time on these diets and vitamin B12 concentrations is not clear. The objectives of this study were to investigate differences in serum vitamin B12 and folate concentrations between omnivores, vegetarians and vegans and to ascertain whether vitamin B12 concentrations differed by age and time on the diet. SUBJECTS/METHODS: A cross-sectional analysis involving 689 men (226 omnivores, 231 vegetarians and 232 vegans) from the European Prospective Investigation into Cancer and Nutrition Oxford cohort. RESULTS: Mean serum vitamin B12 was highest among omnivores (281, 95% CI: 270-292 pmol/l), intermediate among vegetarians (182, 95% CI: 175-189 pmol/l) and lowest among vegans (122, 95% CI: 117-127 pmol/l). In all, 52% of vegans, 7% of vegetarians and one omnivore were classified as vitamin B12 deficient (defined as serum vitamin B12 <118 pmol/l). There was no significant association between age or duration of adherence to a vegetarian or a vegan diet and serum vitamin B12. In contrast, folate concentrations were highest among vegans, intermediate among vegetarians and lowest among omnivores, but only two men (both omnivores) were categorized as folate deficient (defined as serum folate <6.3 nmol/l). CONCLUSION: Vegans have lower vitamin B12 concentrations, but higher folate concentrations, than vegetarians and omnivores. Half of the vegans were categorized as vitamin B12 deficient and would be expected to have a higher risk of developing clinical symptoms related to vitamin B12 deficiency.