Background: Coffee consumption has been linked to various beneficial and detrimental health effects, but data on its relation with mortality are sparse.
Objective: To assess the association between coffee consumption and mortality from cardiovascular disease (CVD), cancer, and all causes during 18 years of follow-up in men and 24 years of follow-up in women.
Design: Sex-specific Cox proportional hazard models were used to investigate the association between coffee consumption and incidence of all-cause and disease-specific mortality in a prospective cohort study.
Setting: Health Professionals Follow-up Study and Nurses' Health Study.
Participants: 41,736 men and 86,214 women with no history of CVD or cancer at baseline.
Measurements: Coffee consumption was assessed first in 1986 for men and in 1980 for women and then every 2 to 4 years through 2004. Investigators documented 6888 deaths (2049 due to CVD and 2491 due to cancer) among men and 11,095 deaths (2368 due to CVD and 5011 due to cancer) among women.
Results: After adjustment for age, smoking, and other CVD and cancer risk factors, the relative risks for all-cause mortality in men across categories of coffee consumption (<1 cup per month, 1 cup per month to 4 cups per week, 5 to 7 cups per week, 2 to 3 cups per day, 4 to 5 cups per day, and >or=6 cups per day) were 1.0, 1.07 (95% CI, 0.99 to 1.16), 1.02 (CI, 0.95 to 1.11), 0.97 (CI, 0.89 to 1.05), 0.93 (CI, 0.81 to 1.07), and 0.80 (CI, 0.62 to 1.04), respectively (P for trend = 0.008). For women, the relative risks were 1.0, 0.98 (CI, 0.91 to 1.05), 0.93 (CI, 0.87 to 0.98), 0.82 (CI, 0.77 to 0.87), 0.74 (CI, 0.68 to 0.81), and 0.83 (CI, 0.73 to 0.95), respectively (P for trend < 0.001). This inverse association was mainly due to a moderately reduced risk for CVD mortality and was independent of caffeine intake. By contrast, coffee consumption was not statistically significantly associated with risk for cancer death after adjustment for potential confounders. Decaffeinated coffee consumption was associated with a small reduction in all-cause and CVD mortality.
Limitation: Coffee consumption was estimated from self-report; thus, some measurement error is inevitable.
Conclusion: Regular coffee consumption was not associated with an increased mortality rate in either men or women. The possibility of a modest benefit of coffee consumption on all-cause and CVD mortality needs to be further investigated.