Prospective study of coffee consumption and all-cause, cancer, and cardiovascular mortality in Swedish women

We investigated whether coffee consumption was associated with all-cause, cancer, or cardiovascular mortality in a prospective cohort of 49,259 Swedish women. Of the 1576 deaths that occurred in the cohort, 956 were due to cancer and 158 were due to cardiovascular disease. We used Cox proportional hazard models with adjustment for potential confounders to estimate multivariable relative risks (RR) and 95 % confidence intervals (CI). Compared to a coffee consumption of 0-1 cups/day, the RR for all cause-mortality was 0.81 (95 % CI 0.69-0.94) for 2-5 cups/day and 0.88 (95 % CI 0.74-1.05) for >5 cups/day. Coffee consumption was not associated with cancer mortality or cardiovascular mortality when analyzed in the entire cohort. However, in supplementary analyses of women over 50 years of age, the RR for all cause-mortality was 0.74 (95 % CI 0.62-0.89) for 2-5 cups/day and 0.86 (95 % CI 0.70-1.06) for >5 cups/day when compared to 0-1 cups/day. In this same subgroup, the RRs for cancer mortality were 1.06 (95 % CI 0.81-1.38) for 2-5 cups/day and 1.40 (95 % CI 1.05-1.89) for >5 cups/day when compared to 0-1 cups/day. No associations between coffee consumption and all-cause mortality, cancer mortality, or cardiovascular mortality were observed among women below 50 years of age. In conclusion, higher coffee consumption was associated with lower all-cause mortality when compared to a consumption of 0-1 cups/day. Furthermore, coffee may have differential effects on mortality before and after 50 years of age.