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

Abstract

Background: Although whole-grain consumption has been associated with a lower risk of cardiovascular diseases (CVD) and mortality in the general population, the association of whole grain with mortality in diabetic patients remains to be determined. This study investigated whole grain and its components cereal fiber, bran, and germ in relation to all-cause and CVD-specific mortality in patients with type 2 diabetes mellitus.

Methods and results: We followed 7822 US women with type 2 diabetes mellitus in the Nurses' Health Study. Dietary intakes and potential confounders were assessed with regularly administered questionnaires. We documented 852 all-cause deaths and 295 CVD deaths during up to 26 years of follow-up. After adjustment for age, the highest versus the lowest fifths of intakes of whole grain, cereal fiber, bran, and germ were associated with 16% to 31% lower all-cause mortality. After further adjustment for lifestyle and dietary risk factors, only the association for bran intake remained significant (P for trend=0.01). The multivariate relative risks across the fifths of bran intake were 1.0 (reference), 0.94 (0.75 to 1.18), 0.80 (0.64 to 1.01), 0.82 (0.65 to 1.04), and 0.72 (0.56 to 0.92). Similarly, bran intake was inversely associated with CVD-specific mortality (P for trend=0.04). The relative risks across the fifths of bran intake were 1.0 (reference), 0.95 (0.66 to 1.38), 0.80 (0.55 to 1.16), 0.76 (0.51 to 1.14), and 0.65 (0.43 to 0.99). Similar results were observed for added bran alone.

Conclusions: Whole-grain and bran intakes were associated with reduced all-cause and CVD-specific mortality in women with diabetes mellitus. These findings suggest a potential benefit of whole-grain intake in reducing mortality and cardiovascular risk in diabetic patients.