Vegetarian diets, chronic diseases and longevity

Abstract

Vegetarians form a non-homogenous group consisting of semivegetarians (plant food, dairy products, eggs and fish), lacto-ovo vegetarians (plant food, dairy products, eggs) and vegans (plant food only). According to pure vegetarian ideologists, people consuming vegetarian diet have better health and live longer than nonvegetarians, because persons consuming milk, dairy products, meat, eggs and fish are at health risk. In fact the most healthy people in Europe are inhabitants of Iceland, Switzerland and Scandinavia, consuming great amounts of food of animal origin. Meta-analysis of several prospective studies showed no significant differences in the mortality caused by colorectal, stomach, lung, prostate or breast cancers and stroke between vegetarians and "health-conscious" nonvegetarians. In vegetarians, a decrease of ischemic heart disease mortality was observed probably due to lower total serum cholesterol levels, lower prevalence of obesity and higher consumption of antioxidants. Very probably, an ample consumption of fruits and vegetables and not the exclusion of meat make vegetarians healthful. Now, the largest cohort study of diet and health on more than half million of persons, the European Prospective Investigation into Cancer and Nutrition (EPIC) study, will bring new data on the relationships between diet, lifestyle and environmental factors and the incidence of cancer, cardiovascular and other chronic diseases. Vegetarianism is a form of food restriction; and in our overfed society, food restriction is a plus unless it results in a nutritional deficiency (Fig. 1, Tab. 2, Ref. 18).