Coffee consumption and risk of myocardial infarction among older Swedish women

Numerous studies have examined the association between coffee consumption and risk of myocardial infarction (MI), but results have been inconsistent. Case-control studies generally suggest a harmful effect of coffee drinking, whereas cohort studies have mostly shown no association. Recent studies found that coffee may lower the risk of diabetes, a major coronary risk factor. The authors prospectively examined the effect of coffee consumption on MI risk in 32,650 older Swedish women, aged 40-74 years, participating in the Swedish Mammography Cohort; 459 cases of MI developed during 165,896 person-years of follow-up from 1997 to 2002. After adjustment for age, coronary heart disease risk factors, and dietary variables, the relative risk of MI associated with drinking >/=5 cups/week versus 0-4 cups/week was 0.68 (95% confidence interval (CI): 0.43, 1.07). The authors observed a nonsignificant trend toward lower risk with higher consumption levels. Compared with that for 0-4 cups/week, the relative risks of MI were 0.84 (95% CI: 0.51, 1.38) for 5-7 cups/week, 0.65 (95% CI: 0.41, 1.03) for 2-3 cups/day, 0.64 (95% CI: 0.39, 1.04) for 4-5 cups/day, and 0.65 (95% CI: 0.37, 1.12) for >/=6 cups/day (p-trend = 0.07). Contrary to previous case-control studies, the authors concluded that coffee consumption does not increase MI risk. Coffee consumption of >/=5 cups/week was nonsignificantly inversely associated with MI risk among older Swedish women.