Associations of Dietary Iron Intake With Mortality From Cardiovascular Disease: The JACC Study

BACKGROUND We investigated the relationship between dietary iron intake and mortality from cardiovascular disease (CVD) in a population-based sample of Japanese adults. METHODS The study cohort consisted of 58 615 healthy Japanese (23 083 men and 35 532 women), aged between 40 and 79 years, who had no history of stroke, coronary heart disease (CHD), or cancer at baseline. Dietary iron intake was assessed at baseline by a validated food frequency questionnaire administered between 1988 and 1990 as part of the Japan Collaborative Cohort (JACC) Study. RESULTS We documented 2690 (1343 men and 1347 women) deaths from CVD: 1227 (607 men and 620 women) deaths from total stroke, 651 from ischemic stroke (355 men and 296 women), 459 (196 men and 263 women) from hemorrhagic stroke, and 557 (311 men and 246 women) from CHD. Dietary intake of total iron was positively associated with mortality from total and ischemic stroke and total CVD in men. The multivariable hazard ratio for the highest versus the lowest quintile of total iron intake was 1.43 (95% CI, 1.02-2.00; P for trend = 0.009) for total stroke and 1.27 (1.01-1.58; 0.023) for total CVD in men. Dietary total iron intake was not associated with mortality from other endpoints in men, and was not associated with any endpoints in women. CONCLUSIONS Dietary intake of total iron was positively associated with mortality from stroke and total CVD in Japanese men.