Vegetarian Diets and the Risk of Type 2 Diabetes

We review epidemiological evidence indicating a lower risk of diabetes type 2 in persons following various types of vegetarian diets. We also review evidence suggesting a link between red or processed meat intake and diabetes, metabolic syndrome components, and insulin resistance. A number of plausible mechanisms support the biological plausibility of epidemiological observations of the diabetes-promoting effects of processed meat. However, direct and interventional evidence that red meat consumption impairs insulin sensitivity or increases insulin resistance is lacking. The most convincing explanation of the lower risk of type 2 diabetes in vegetarians is the totality of lower BMI and benefits of generally healthier diets than those consumed by omnivores, in addition to the absence of processed and perhaps also unprocessed meat in the diet.