Inverse association of tea and flavonoid intakes with incident myocardial infarction: The Rotterdam Study

Abstract

Background: Dietary flavonoids may protect against cardiovascular disease, but evidence is still conflicting. Tea is the major source of flavonoids in Western populations. Objective: The association of tea and flavonoid intake with incident myocardial infarction was examined in the general Dutch population. Design: A longitudinal analysis was performed with the use of data from the Rotterdam Study - a population-based study of men and women aged ≥55 y. Diet was assessed at baseline (1990-1993) with a validated semiquantitative food-frequency questionnaire. The analysis included 4807 subjects with no history of myocardial infarction, who were followed until 31 December 1997. Data were analyzed in a Cox regression model, with adjustment for age, sex, body mass index, smoking status, pack-years of cigarette smoking, education level, and daily intakes of alcohol, coffee, polyunsaturated fat, saturated fat, fiber, vitamin E, and total energy. Results: During 5.6 y of follow-up, a total of 146 first myocardial infarctions occurred, 30 of which were fatal. The relative risk (RR) of incident myocardial infarction was lower in tea drinkers with a daily intake >375 mL (RR: 0.57; 95% CI: 0.33, 0.98) than in nontea drinkers. The inverse association with tea drinking was stronger for fatal events (0.30; 0.09, 0.94) than for nonfatal events (0.68; 0.37, 1.26). The intake of dietary flavonoids (quercetin + kaempferol + myricetin) was significantly inversely associated only with fatal myocardial infarction (0.35; 0.13, 0.98) in upper compared with lower tertiles of intake. Conclusions: An increased intake of tea and flavonoids may contribute to the primary prevention of ischemic heart disease.