Higher consumption of coffee and specifically decaffeinated coffee raises the risk of rheumatoid arthritis, while caffeinated coffee, tea and caffeine intake doesn't.
In the methodology, a dose-response meta-analysis of prospective cohort studies was carried out to evaluate the association between dietary caffeine, and different types of coffee and tea consumption with rheumatoid arthritis (RA). Relevant research papers were identified through a database search in PubMed/Medline, Scopus and EMBASE until July 2021. The studies considered different types of coffee, caffeinated or decaffeinated, tea or caffeine exposure with RA as the main or one of the outcomes. Out of 742 publications, five studies were selected for inclusion in the meta-analysis. Pooled relative risks were calculated through a fixed-effects model. Both linear and non-linear dose-response analyses were conducted to inspect dose-response relations.
The analysis of results revealed a significant association between the consumption of coffee, especially decaffeinated coffee and increased risk of RA, when comparing between extreme categories of consumption. For each additional cup of coffee consumed daily, there was a notable increase in the risk of RA. However, this study found no significant link between the intake of caffeinated coffee, tea or caffeine intake and the risk of RA.