Although previous studies have linked high consumption of whole grains to a lower risk of developing type-2 diabetes and heart disease, the new study indicates whole grains may help protect the heart even for those who already exhibit type-2 diabetes, which raises the risk of heart disease.
Dr Lu Qi, one of the study’s researchers, told NutraIngredientsUSA.com: “Increased intake of whole grain products, especially bran, may lower the risk of mortality especially cardiovascular mortality in diabetic patients.”
Explaining the significance of the research Qi added: “This is the first study investigating the effects of whole grain intake on mortality in patients of type 2 diabetes.”
Less likely to die
The researchers at Harvard Medical School, Boston found that among 7,800 US women followed for 26 years, those with the highest bran intake were 28 percent less likely to die during the review period than those who consumed the least bran.
Also, they were 35 percent less likely to die of cardiovascular disease.
Although there was no conclusive proof that a bran-rich diet reduced risks, the link between higher bran intake and lower death rates remained even after accounting for other diet factors, such as fat intake and calories and lifestyle factors. Those included weight, exercise levels, smoking history and drinking habits.
Qi and the research team concluded that bran intake itself may help reduce diabetics' risk of premature death.
“We would recommend diabetic patients to consume more whole grains, less refined carbohydrates (such as white rice and pasta made with white flour),” Qi said.
The United States Department of Agriculture’s (USDA’s) nutrition website MyPyramid.gov identifies whole grains as containing the entire grain kernel including the bran, germ, and endosperm. Examples include: Whole-wheat flour, bulgur (cracked wheat), oatmeal, whole cornmeal and brown rice.
In contrast, refined grains have been milled; a process that removes the bran and germ. “This is done to give grains a finer texture and improve their shelf life, but it also removes dietary fiber, iron, and many B vitamins,” according to the website. Examples of refined grain products include: White flour, degermed cornmeal, white bread and white rice.
Meanwhile, the research was based on a Nurses' Health Study which every two years surveyed the health of women with type 2 diabetes. Nurses also provided information about their general health, medical history and lifestyle.
Nurses with the highest bran intake consumed on average 9g of bran per day, 10 times more than the lowest-intake group.
“Whole-Grain, Cereal Fiber, Bran, and Germ Intake and the Risks of All-Cause and Cardiovascular Disease–Specific Mortality Among Women With Type 2 Diabetes Mellitus”
Authors: Meian He, Rob van Dam, Eric Rimm, Frank Hu, and Lu Qi.