Whole Grains, Bran Fiber and Diabetes

Over the last several years there has been great research about the positive effects of eating more fiber and whole grains. Eating more fiber can help adolescents reduce their risk of developing diabetes, while eating more fiber can help overweight adults lose more fat in their abdomen - which in and of itself is a risk factor for diabetes. Similarly, eating more whole grains, as opposed to more refined grains, seems to protect against higher fasting insulin scores - another indication of a risk of diabetes.

Researchers affiliated with Harvard Medical School and Tongji Medical College in Hubei, China noted that whole grains tended to help reduce the risk of diabetes and wondered what effect eating more whole grains might have on those who already have diabetes (Circulation 2010;121(20):2162-2168). They made use of information gathered through the Nurses' Health Study (NHS), a study of female nurses which began in 1976 with an initial enrollment of over 121,700 women between the ages of 30 and 55. Each woman reported on their health and lifestyle factors every two years by responding to a standardized questionnaire. Beginning in 1980, they also reported on their dietary habits.

The study included those women who were diagnosed with type 2 diabetes between 1976 and 2006 but excluded those women who were diagnosed with diabetes before the age of 30, who had a history of heart disease, or those who were diagnosed with cancer before the 1980 start of recording dietary intake.

Using the dietary intake questionnaire, the researchers were able to group the diabetic women into five levels of intake of whole grains, from the lowest daily average intake to the highest, while also breaking the components of whole grains out into cereal fiber, bran and germ. After adjusting for the range of ages in the participant women, the researchers found that each additional 20 grams of whole grain per day yielded a 13% reduction in risk of death from all causes.

Looking further at the three main components of whole grains, cereal fiber, bran and germ, led to even more interesting results. Those women who ate the most bran, for example, as compared to those who ate the least, were 35% less likely to die of heart-disease-related illness. The highest cereal fiber intake, however, meant only 11% lower risk of death from heart-disease-related illness.

What this means for you

Even if you already have type 2 diabetes, getting more whole grains, and specifically more bran, in your diet can help you reduce your risk of dying of heart-disease-related causes. Added bran seemed to be key to the improved health risks in this study; adding bran flakes to your morning cereal or oatmeal is a great way to get more bran as well as making your morning meal more satisfying with higher fiber.

Updated 03/24/24