Coffee or tea consumption and the risk of rheumatoid arthritis: a meta-analysis

The aim of this study was to analyze published results for an association between coffee or tea intake and the development of rheumatoid arthritis (RA). We investigated the evidence for a relationship between coffee or tea consumption and the development of RA by performing a meta-analysis of the published results. Five studies (three cohort and two case–control studies) including 134,901 participants (1,279 cases of RA and 133,622 noncases) were considered in the meta-analysis. Meta-analysis of the cohort studies revealed a trend of an association between total coffee intake and RA incidence (relative risk [RR] of the highest versus the lowest group = 4.148, 95 % confidence interval [CI] = 0.792–21.73, p = 0.092). Meta-analysis of case–control studies showed a significant association between total coffee intake and RA incidence (RR = 1.201, 95 % CI = 1.058–1.361, p = 0.005). Combining the data of the cohort and case–control studies showed a significant association between total coffee intake and RA incidence (RR = 2.426, 95 % CI = 1.060–5.554, p = 0.036). Meta-analysis stratified by seropositivity indicated a significant association between coffee consumption and seropositive RA risk (RR = 1.329, 95 % CI = 1.162–1.522, p = 3.5 × 10⁻⁵), but not seronegative RA risk (RR = 1.093, 95 % CI = 0.884–1.350, p = 0.411). No association was found between tea intake and RA incidence (RR = 0.880, 95 % CI = 0.624–1.239, p = 0.463). This meta-analysis of 134,901 participants (most of the participants were controls) suggests that high coffee consumption is associated with an elevated risk of RA development. The association between coffee and RA was found in seropositive RA, but not in seronegative RA.