A 2011 study examined the relationship of diet to incidence of diabetes among Black and non-Black participants in the Adventist Health Study-2. The study participants included 15,200 men and 26,187 women (17.3% black) living in the US and Canada who were free of diabetes. Participants provided demographic, anthropometric, lifestyle and dietary data, while a follow-up questionnaire two years later elicited information on the development of diabetes. Participants were grouped as vegan, lacto ovo vegetarian, pesco vegetarian, semi-vegetarian or non-vegetarian (reference group). The questionnaire results showed that vegetarian diets (vegan, lacto ovo and semi) were all associated with a substantial and independent reduction in diabetes incidence. Blacks have long been associated with having an increased risk for diabetes. The results of this study showed that the protection provided against diabetes from the consumption of vegetarian diets was as great as the excess risk associated with Black ethnicity.
Nutrition, Metabolism and Cardiovascular Diseases 2011 Oct 7. (Tonstad et al.)