Coffee consumption and risk of fractures: a meta-analysis

Introduction: Recent studies have indicated higher risk of fractures among coffee drinkers. To quantitatively assess the association between coffee consumption and the risk of fractures, we conducted this meta-analysis. Material and methods: We searched MEDLINE and EMBASE for prospective studies reporting the risk of fractures with coffee consumption. Quality of included studies was assessed with the Newcastle Ottawa scale. We conducted a meta-analysis and a cumulative meta-analysis of relative risk (RR) for an increment of one cup of coffee per day, and explored the potential dose-response relationship. Sensitivity analysis was performed where statistical heterogeneity existed. Results: We included 10 prospective studies covering 214,059 participants and 9,597 cases. There was overall 3.5% higher fracture risk for an increment of one cup of coffee per day (RR = 1.035, 95% Cl: 1.019-1.052). Pooled RRs were 1.049 (95% Cl: 1.022-1.077) for women and 0.910 (95% Cl: 0.873-0.949) for men. Among women, RR was 1.055 (95% Cl: 0.999-1.114) for younger participants, and 1.047 (95% CI: 1.016-1.080) for older ones. Cumulative meta-analysis indicated that risk estimates reached a stabilization level (RR = 1.035, 95% Cl: 1.019-1.052), and it revealed a positive dose-response relationship between coffee consumption and risk of fractures either for men and women combined or women specifically. Conclusions: This meta-analysis suggests an overall harm of coffee intake in increasing the risk of fractures, especially for women. But current data are insufficient to reach a convincing conclusion and further research needs to be conducted.