Background: Considerable controversy exists on the association between coffee consumption and cardiovascular disease (CVD) risk. A meta-analysis was performed to assess the dose-response relationship of long-term coffee consumption with CVD risk.
Methods and results: PubMed and EMBASE were searched for prospective cohort studies of the relationship between coffee consumption and CVD risk, which included coronary heart disease, stroke, heart failure, and CVD mortality. Thirty-six studies were included with 1 279 804 participants and 36 352 CVD cases. A nonlinear relationship of coffee consumption with CVD risk was identified (P for heterogeneity=0.09, P for trend <0.001, P for nonlinearity <0.001). Compared with the lowest category of coffee consumption (median, 0 cups per day), the relative risk of CVD was 0.95 (95% confidence interval, 0.87-1.03) for the highest category (median, 5 cups per day) category, 0.85 (95% confidence interval, 0.80-0.90) for the second highest category (median, 3.5 cups per day), and 0.89 (95% confidence interval, 0.84-0.94) for the third highest category (median, 1.5 cups per day). Looking at separate outcomes, coffee consumption was nonlinearly associated with both coronary heart disease (P for heterogeneity=0.001, P for trend <0.001, P for nonlinearity <0.001) and stroke (P for heterogeneity=0.07, P for trend <0.001, P for nonlinearity <0.001; P for trend differences >0.05) risks.
Conclusions: A nonlinear association between coffee consumption and CVD risk was observed in this meta-analysis. Moderate coffee consumption was inversely significantly associated with CVD risk, with the lowest CVD risk at 3 to 5 cups per day, and heavy coffee consumption was not associated with elevated CVD risk.
Keywords: cardiovascular diseases; coffee; meta-analysis.