Study Shows Whole-Grain Foods Lower Cardio Risk in People With Diabetes

People with diabetes who eat plenty of bran-rich whole grains appear to have a reduced risk of death from heart attack, stroke, and other cardiovascular causes, a new study shows.

Researchers from Harvard University followed almost 8,000 nurses with type 2 diabetes for almost three decades.

They found that women who ate the most bran had a 35% lower risk of death from heart disease and a 28% lower risk of death from all causes than women who ate the least.

Compared to people without diabetes, diabetic people have two to three times the risk of heart disease and early death.

The new research suggests eating a balanced diet that includes complex carbohydrates in the form of whole grains can help lower this risk, American Heart Association spokesman Robert Eckel, MD, tells WebMD.

Eckel is a professor of medicine at the University of Colorado in Denver.

"Many diabetics still believe they should limit carbohydrates, including complex carbohydrates," he says. "Certainly refined grains and simple sugars raise blood sugar and should be limited. But it looks like eating whole grains is not only safe, but beneficial."

Anatomy of a Grain

An unrefined grain of wheat, rice, oat, corn, or any other cereal contains three parts: the tough outer bran layer, the middle endosperm, and the inner kernel or germ.

The fiber in grain is found in the bran, while bran and germ contain most of its vitamins and minerals.

Refined grain products, such as white flour and white rice, contain only the starchy endosperm. B vitamins and iron, but not fiber, are usually added back after processing.

In the newly published investigation, researchers examined data from the ongoing Nurses Health Study, which is one of the largest and most detailed studies of women's health in the United States.

Every two years, the study participants were asked to complete questionnaires examining their health and lifestyles, which included detailed information about the foods they ate.

A total of 7,822 women diagnosed with type 2 diabetes aged 30 or older were included in the latest analysis, which appears in this week's issue of the journal Circulation.

During up to 26 years of follow-up, 852 women died, including 295 who died as a result of heart attack, stroke, or other cardiovascular causes.

Using the food questionnaires, the researchers were able to estimate the women's daily consumption of whole grains, bran, germ, and fiber.

Women who ate the most bran ate more than 10 times as much each day as women who ate the least (9.73 grams vs. 0.8 grams).

After considering other cardiovascular risk factors, bran consumption was strongly associated with a reduced risk of death from heart attack and stroke, study researcher Lu Qi, MD, PhD, tells WebMD.