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

Abstract

Dietary flavonoids may protect against cardiovascular disease, but evidence is still conflicting. Tea is the major source of flavonoids in Western populations. The association of tea and flavonoid intake with incident myocardial infarction was examined in the general Dutch population. A longitudinal analysis was performed with the use of data from the Rotterdam Study-a population-based study of men and women aged >or=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. 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. An increased intake of tea and flavonoids may contribute to the primary prevention of ischemic heart disease.