Vegetarian Congress research presentations

Research presentations

Wednesday, March 26, 1997

# 32

Mortality in Vegetarians -- Timothy Key

Data for 27,808 vegetarians and 48,364 non-vegetarians in five prospective studies were pooled. Mortality ratios at ages 16 to 89, adjusted for age, sex, smoking and study, were calculated by Poisson regression. After a mean of 10.6 years of follow up there were 8,330 deaths before age 90. In comparison with non-vegetarians, vegetarians had a 25% reduction in mortality from ischaemic heart disease (rate ratio 0.75, 95% confidence interval 0.68-0.82, p<0.00001). This reduction in mortality among vegetarians varied with age at death: rate ratios were 0.52 (95% CI 0.38-0.71), 0.71 (95% CI 0.62-0.81) and 0.86 (95% CI 0.75-0.98) for deaths from ischaemic heart disease at ages <65, 65-79 and 80-89 respectively. Mortality rate ratios in vegetarians compared to non-vegetarians were 1.00 (95% CI 0.78-1.29) for colorectal cancer, 1.02 (95% CI 0.76-1.35) for breast cancer and 0.89 (95% CI 0.61-1.29) for prostate cancer. For all causes of death the rate ratio for vegetarians was 0.91 (95% CI 0.87-0.96, 2p<0.001), largely due to their lower mortality from ischaemic heart disease. We conclude that vegetarians have a lower risk of dying from ischaemic heart disease than non-vegetarians. There is no evidence from this analysis that a vegetarian diet alters the mortality rates for cancers of the colorectum, breast or prostate.

# 33

Ischemic Heart Disease and Vegetarianism: Fourteen Year Follow Up to the Oxford Vegetarian Study -- Margaret Thorogood

The Oxford Vegetarian Study has a cohort of around 6,000 non-meat eaters and around 5,000 meat eaters who have been studied since the early 1980's. In this paper the 14-year mortality follow up of the study participants is reported. There was a significant 38% reduction in mortality from ischaemic heart disease in vegetarians as compared with those who ate meat regularly but no difference in mortality from non-IHD causes of death. The participants completed a brief food frequency questionnaire at recruitment, and the relative risk of ischaemic heart disease mortality was estimated according to reported consumption of selected foods and intake of fat and fibre. Consumption of animal fat showed a strong relationship with risk of death from ischaemic heart disease with those in the highest tertile of animal fat consumption having a more than twofold increase in risk. There were no convincing relationships between risk of IHD death and consumption of dietary fibre or fruit, nuts and vegetables.

# 34

Diet and Chronic Diseases Among California Adventists -- Gary Fraser

In 1976, food frequency data was collected from 34,192 California Seventh-day Adventists. These subjects were then followed for 6 years to find all cases of incident coronary artery disease and cancer, and for 13 years to find all deaths.

For nearly all endpoints, vegetarians had lower risk then non-vegetarian Adventists. Frequent consumption of legumes was associated with reduced incidence of pancreatic cancer, and colon cancer (amongst non-vegetarians); frequent consumption of fruit was associated with lower incidence of lung, pancreatic, and prostate cancer. Consuming nuts 4-5 times per week was associated with a halving of coronary event risk, and a preference for whole grain bread was associated with 30% lower risk of these events. Frequent consumption of red meats was associated with higher rates of bladder cancer, and in men, fatal coronary events. Frequent consumption of white and red meats was associated with higher incidence of colon cancer (when legume consumption was low). Higher intake of polyunsaturated fats was associated with lower frequency of incident coronary events and also prostate cancer. Consequently, the advantages of a vegetarian diet seem to be both due to higher consumption of legumes, fruits, and polyunsaturated fats, as well as the lower consumption of meats.

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