Whole grain, bran intake reduced CV mortality in women with type 2 diabetes

Women with type 2 diabetes who ate more than 9 g of bran per day had a 35% lower risk for death from cardiovascular disease and a 28% lower risk for all-cause mortality compared with women who ate less bran, according to new study findings.

Researchers assessed the potential benefits of whole grain — including cereal fiber, bran and germ — on all-cause and CV-specific mortality in 7,822 women with type 2 diabetes included in the Nurses’ Health Study. The women were diagnosed with diabetes after age 30 years. Questionnaires were administered to the women and included questions on dietary intake and potential confounders. The researchers divided the women into five groups based on their consumption of whole grain and its components.

During 26 years of follow-up, 852 deaths occurred, including 295 from CVD in the women with diabetes.

Women in the top fifth of whole grain consumption had a lower BMI, were less likely to smoke, more likely to be engaged in physical activity, to use postmenopausal hormones and to have hypercholesterolemia or hypertension compared with women in the lowest fifth of whole grain intake. Women who ate more whole grains also had higher folate, multivitamin and vitamin E supplement intake and lower alcohol, saturated fat, polyunsaturated fat and trans fat intake.

The highest vs. lowest fifths of whole grain, cereal fiber, bran and germ intake were associated with 16% to 31% lower risk for all-cause mortality, after adjusting for age (P=.004). Compared with the lowest fifth of whole grain intake, the risk ratio for all-cause mortality in the highest fifth of intake was 0.8 (95% CI, 0.64-1.0).

Women in the highest group for added bran had a 55% risk reduction for death from all causes and a 64% risk reduction in CVD mortality compared with women who ate no added bran.

When the researchers adjusted for lifestyle and dietary risk factors, only the association with bran remained statistically significant and independent of those factors (P=.01).

“These findings suggest a potential benefit of whole grain, and particularly bran, in reducing death and CV risk in diabetic patients,”Lu Qi, MD, PhD, assistant professor of medicine at Harvard Medical School and assistant professor of nutrition at Harvard Public School of Health, said in a press release.

Qi L. Circulation. 2010;doi:10.1161/CIRCULATIONAHA.109.907360.