Background: Despite emerging evidence of the role of flavonoids in cardiovascular disease (CVD) prevention, the association remains unclear.
Objective: We examined whether flavonoids and selected flavonols and flavones or their food sources are associated with CVD risk.
Design: Women (n = 38 445) free of CVD and cancer participated in a prospective study with a mean follow-up of 6.9 y. On the basis of a food-frequency questionnaire, total flavonoids and selected flavonols and flavones were categorized into quintiles, and food sources were categorized into 4 groups. Relative risks were computed for important vascular events (519 events; excluding revascularizations) and CVD (729 events), including myocardial infarction, stroke, revascularization, and CVD death.
Results: The mean flavonoid intake was 24.6 +/- 18.5 mg/d, primarily as quercetin (70.2%). For both CVD and important vascular events, no significant linear trend was observed across quintiles of flavonoid intake (P = 0.63 and 0.80, respectively). No individual flavonol or flavone was associated with CVD. Broccoli and apple consumption were associated with nonsignificant reductions in CVD risk: 25-30% and 13-22%, respectively. A small proportion of women (n = 1185) consuming > or =4 cups (946 mL) tea/d had a reduction in the risk of important vascular events but with a nonsignificant linear trend (P = 0.07).
Conclusions: Flavonoid intake was not strongly associated with a reduced risk of CVD. The nonsignificant inverse associations for broccoli, apples, and tea with CVD were not mediated by flavonoids and warrant further study.