Vegetarianism appears to cut heart disease risk by a third

by Peter Mas Mollinedo – Vegetarians have a 32% lower risk of hospitalization or death from heart disease than persons who eat meat and fish, researchers from the University of Oxford (UK) reported on January 30, 2013 in the American Journal of Clinical Nutrition.

‘Most of the difference in risk is probably caused by effects on cholesterol and blood pressure, and shows the important role of diet in the prevention of heart disease,’ said Dr. Francesca Crowe, lead author of the study at the Cancer Epidemiology Unit, University of Oxford.

This study comparing rates of heart disease between vegetarians and non-vegetarians is the largest ever conducted in the UK. Heart disease is the single largest cause of death in developed countries.

Approximately 45,000 volunteers from England and Scotland enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Oxford study. Of these, 34% were vegetarian. The unusual size of the vegetarian cohort enabled the researchers to estimate more accurately the relative risks between the two groups.

At baseline, subjects completed questionnaires about their general health and lifestyle, including detailed questions on diet and exercise, and other factors like smoking and alcohol consumption.

About 20,000 of the subjects had their blood pressures recorded and submitted blood samples for cholesterol testing.

The researchers tracked the subjects until 2009 and identified 1235 cases of heart disease, with 169 deaths and 1066 hospital diagnoses. They validated heart disease cases using data from the Myocardial Ischaemia National Audit Project (MINAP).

They found that the vegetarian subjects had lower blood pressures and cholesterol levels than non-vegetarians, a possible explanation, the authors suggested, of their reduced risk of heart disease.

They noted that vegetarians typically had lower body mass indices (BMI). But they found that even after adjusting the results to exclude the effects of BMI, vegetarians remain 28% less likely to develop heart disease. They arrived at the figure of 32% risk reduction after adjusting the results for age, smoking, alcohol intake, physical activity, educational level and socioeconomic background.

The EPIC-Oxford cohort study was funded by Cancer Research UK and the Medical Research Council and carried out by the Cancer Epidemiology Unit at the University of Oxford.