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

Abstract

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.

Identifying vegetarians and their food consumption according to self-identification and operationalized definition in Finland

“…A link between lower BMI and vegetarianism has also consistently been reported (25)(26)(27) , as well as an overall decline in mortality (28) . Even though the health effects of vegetarianism and veganism are largely acknowledged, some uncertainties remain (29,30) , especially with regard to sufficient vitamin B 12 and vitamin D concentrations in the diet (31,32) .…”

Vegetarian diets, low-meat diets and health: a review

“…Vegetarian diets and prevention of chronic disease CVD A pooled analysis of five prospective cohort studies, involving approximately 76 000 subjects from the USA, the UK and Germany, over a mean follow-up period of 10?6 years, reported that vegetarians had a 24 % (95 % CI 6 %, 38 %) reduction in mortality from CHD compared with regular meat-eaters (12) . Further characterisation of the vegetarian cohorts within that analysis found that the greatest reductions in CHD mortality (34 %) were observed in individuals eating fish but no meat and in lacto-ovo-vegetarians when compared with regular meateaters.…”

“…Several studies have consistently reported lower vitamin B 12 status and higher homocysteine levels in vegetarians, particularly vegans, when compared with omnivores (72,73) . Purported plant-based sources (tempeh, algae extracts and sea vegetables) have been found to contain more inactive corrinoids than true vitamin B 12 (71) and thus they are not reliable sources of B 12 . Risk of vitamin B 12 deficiency in vegans is increased if the diet is not supplemented with fortified products (fortified yeast extract, fortified soya products and breakfast cereals).…”

Colorectal cancer in India: controversies, enigmas and primary prevention

“…As it happens with good scientific research practises, almost all the large studies with designs to minimize bias and confounding failed to provide consistent results or substantial reduction in CRC with diet high in fruits and vegetables [17][18][19][20][21][22][23]. The first credible report showing no protective effect of a vegetarian diet against CRC was a meta-analysis of 5 prospective studies of vegetarians living in Western countries [17]. A more recent study of British vegetarians found a 12% non significant increase in CRC among the vegetarians in comparison to meat eaters [18].…”