Background and purpose: Higher intake of whole grains may exert cardiometabolic benefits, although findings on stroke risk are inconclusive. The potentially differential effects of individual whole grain foods on ischemic stroke have not been examined.
Methods: We analyzed whole grain consumption in relation to ischemic stroke among 71 750 women from the Nurses' Health Study and 42 823 men from the Health Professionals Follow-up Study who were free of cardiovascular disease, diabetes mellitus, and cancer at baseline (1984 and 1986, respectively) through 2010 using a Cox proportional hazards model. Validated semiquantitative food frequency questionnaires were used to assess consumption of whole grain intake, including whole grain cold breakfast cereal, dark bread, oatmeal, brown rice, popcorn, bran, and germ. Self-reported incident cases of ischemic stroke were confirmed through medical record review.
Results: During 2 820 128 person-years of follow-up in the 2 cohorts, 2458 cases of ischemic stroke were identified and confirmed. Intake of total whole grains was not associated with risk of ischemic stroke after adjustment for covariates: the pooled hazard ratio (95% confidence interval) comparing extreme intake levels was 1.04 (0.91-1.19). However, intake of whole grain cold breakfast cereal and total bran was inversely associated with ischemic stroke after multivariate adjustment: the pooled hazard ratios (95% confidence intervals) were 0.88 (0.80-0.96; Ptrend=0.008) and 0.89 (0.79-1.00; Ptrend=0.004), respectively. Other whole grain foods were not associated with a lower risk of ischemic stroke.
Conclusions: Although overall consumption of whole grains was not associated with lower risk of ischemic stroke, greater consumption of whole grain cold breakfast cereal and bran was significantly associated with a lower risk of ischemic stroke. More studies are needed to replicate these associations between individual whole grain foods and risk of ischemic stroke among other populations.
Keywords: breakfast; cohort studies; meta-analysis; stroke; whole grains.
© 2017 American Heart Association, Inc.