Coffee consumption and myocardial infarction in women.

Whether coffee consumption increases the risk of coronary heart disease has not yet been established. In a case-control study of nonfatal myocardial infarction among Massachusetts women aged 45-69 years in 1986-1990, 858 cases with first infarctions were compared with 858 community controls matched on age and town precinct. Detailed information on coffee drinking, cigarette smoking, and other factors was obtained by telephone interview. Relative risks (as estimated by odds ratios) and their 95% confidence intervals were computed from multiple logistic regression analyses that controlled for smoking and other risk factors. The risk of myocardial infarction increased with increasing number of cups per day among both drinkers of any type of coffee and drinkers of caffeine-containing coffee only: tests for trend, p = 0.002 and p = 0.0004, respectively. For consumption of caffeine-containing coffee alone, the relative risk estimates for 5-6 cups, 7-9 cups, and 10 or more cups per day relative to less than 1 cup per day were 1.4 (95% confidence interval (CI) 0.8-2.5), 2.1 (95% CI 0.9-4.9), and 2.5 (95% CI 1.0-6.5), respectively. No increase was observed for fewer than 5 cups per day. The positive association with heavy coffee drinking was present among nonsmokers as well as smokers. These findings and other recent studies suggest that heavy coffee consumption increases the risk of myocardial infarction.