New research published online recently suggests that following a vegetarian diet and exercising at least three times a week significantly reduces the risk of diabetes among African Americans, who are normally twice as likely to be diagnosed with diabetes as non-Hispanic whites. You can read about the study, led by Dr Serena Tonstad, a professor at Loma Linda University in California, online in the October edition of Nutrition, Metabolism & Cardiovascular Diseases.

Tonstad and colleagues found that compared to non-vegetarian blacks, vegan blacks (vegans eat no animal products at all, including eggs and dairy) had a 70% reduced risk of diabetes, and vegetarian blacks (those who don't eat meat but do eat eggs and dairy) had a 53% reduced risk.

They also found that blacks who exercised three or more times a week compared to once a week or not at all, had a 35% reduced risk of being diagnosed with diabetes.

Tonstad told the press:

"These findings are encouraging for preventing type 2 diabetes in the black population, which is more susceptible to the disease than other populations."

For the study, the researchers reviewed prospective data that was obtained by following 7,172 black Seventh-day Adventists taking part in the Adventist Health Study-2.

Adventists are protestants that follow a vegetarian diet and abstain from alcohol and tobacco. They are a much sought after population by researchers studying links between diet and disease because data from participants following such a way of life presents fewer confounding variables that might distort the results.

The participants filled in questionnaires that asked them how often they consumed over 100 types of food. From their responses the researchers then grouped them according to their diet.

Tonstad and colleagues also analyzed data from 34,215 non-black Adventists and found a similar pattern between reduced risk for diabetes and vegetarian diet.

They said the findings confirm those of cross-sectional studies that showed strong links between following a vegetarian diet and reduced risk of diabetes. Cross-sectional studies are like a snapshot, they don't follow people over a period of time as prospective studies do, and so cannot establish cause and effect direction, they can only find links and their strength.

Tonstad said one reason why a vegetarian diet might protect against diabetes is that it typically contains a higher proportion of high-fiber foods such as fruit and vegetables. Also, whole grains, beans and other legumes are known to improve glycemic control which slows the rate of carbohydrate absorption and thus reduces risk of diabetes.

The Department of Health and Human Services estimates that African Americans are not only at higher risk of developing diabetes, but they are also more likely to experience complications related to the disease, such as as end-stage renal disease and lower-extremity amputations.

Tonstad said:

"A vegetarian diet may be a way to counteract the increased diabetes risk for the black population."

A grant from the National Institutes of Health and funds from the School of Public Health at Loma Linda University helped pay for the study.

Written by Catharine Paddock PhD