Coffee drinking and myocardial infarction in young women.

The effect of consumption of caffeine-containing coffee on the risk of myocardial infarction in women 30-49 years of age was investigated. In this study 487 patients with first infarctions were compared with 980 controls whose admissions were for acute emergencies. Overall and in various subgroups, coffee drinking and myocardial infarction were weakly and not significantly associated: the overall estimated relative risk for women drinking at least five cups daily, compared with women drinking none, was 1.4 after control for all identified potential confounding factors (95% confidence interval, 1.0-1.9). Also, the frequency of coffee drinking was greater among controls, whose admissions were for acute emergencies, than among other patients without myocardial infarction, most of whom had been admitted for chronic conditions. If patients of the latter type tend to avoid coffee, then their inclusion in the control series of previous hospital-based studies may have led to overestimation of the magnitude of the association between coffee and myocardial infarction.