Whole-grain consumption and risk of coronary heart disease: results from the Nurses' Health Study

Background: Although current dietary guidelines for Americans recommend inc reased intake of grain products to prevent coronary heart disease (CHD), ep idemiologic data relating whole-grain intake to the risk of CHD are sparse. Objective: Our objective was to evaluate whether high whole-grain intake re duces risk of CHD in women. Design: In 1984, 75521 women aged 38-63 y with no previous history of cardi ovascular disease or diabetes completed a detailed, semiquantitative food-f requency questionnaire (SFFQ) and were followed for 10 y, completing SFFQs in 1986 and 1990. We used pooled logistic regression with 2-y intervals to model the incidence of CHD in relation to the cumulative average diet from all 3 cycles of SFFQs. Results: During 729472 person-years of follow-up, we documented 761 cases o f CHD (208 of fatal CHD and 553 of nonfatal myocardial infarction). After a djustment for age and smoking, increased whole-grain intake was associated with decreased risk of CHD. For increasing quintiles of intake, the corresp onding relative risks (RRs) were 1.0 (reference), 0.86, 0.82, 0.72, and 0.6 7 (95% CI comparing 2 extreme quintiles: 0.54, 0.84; P for trend < 0.001). After additional adjustment for body mass index, postmenopausal hormone use , alcohol intake, multivitamin use, vitamin E supplement use, aspirin use, physical activity, and types of fat intake, these RRs were 1.0, 0.92, 0.93, 0.83, and 0.75 (95% CI: 0.59, 0.95; P for trend = 0.01). The inverse relat ion between whole-grain intake and CHD risk was even stronger in the subgro up of never smokers (RR = 0.49 for extreme quintiles; 95% CI: 0.30, 0.79; P for trend = 0.003). The lower risk associated with higher whole-grain inta ke was not fully explained by its contribution to intakes of dietary fiber, folate, vitamin B-6, and vitamin E. Conclusions: Increased intake of whole grains may protect against CHD.