Coffee consumption and risk of coronary heart diseases: A meta-analysis of 21 prospective cohort studies

Abstract

Background A large amount of cohort studies addressed coffee consumption and risk of coronary heart disease (CHD) and yielded inconsistent results. We conducted a meta-analysis to estimate the pooling effects. Methods We searched for all published English articles indexed in MEDLINE or PubMed from January 1966 to January 2008. Twenty-one independent prospective cohort studies, which tested CHD risk by coffee consumption, were identified. A general variance-based method was used to pool the relative risks (RR). 15,599 cases from 407,806 participants were included in pooling the overall effects. Results As compared to the light coffee consumption (< 1 cup/d in US or ≤ 2 cups/d in Europe), under the random-effects model, the pooled CHD RRs (95% CI) for all studies combined were 0.96 (0.87–1.06), 1.04 (0.92–1.17) and 1.07 (0.87–1.32) for the moderate (1–3 or 3–4 cups/d), heavy (4–5 or 5–6 cups/d) and very heavy (≥ 6 or ≥ 7 cups/d) categories of coffee consumption (all p > 0.05); Moderate coffee consumption showed significantly lower CHD RR (95% CI) of 0.82 (0.73–0.92) ( p < 0.001) in women, and of 0.87 (0.80–0.86) ( p = 0.001) in men and women followed ≤ 10 years. Conclusion Our findings do not support the hypothesis that coffee consumption increases the long-term risk of coronary heart disease. Habitual moderate coffee drinking was associated with a lower risk of CHD in women.