Effect of curcumin on inflammatory markers and disease activity in patients with rheumatoid arthritis: A meta-analysis

Background: Curcumin has been proposed as a potential adjunctive anti-inflammatory therapeutic option in rheumatoid arthritis (RA); however, the evidence regarding its clinical efficacy remains inconsistent. This meta-analysis aimed to evaluate whether curcumin supplementation improves disease activity and systemic inflammatory parameters in patients with RA. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria, PubMed, Cochrane Library, Web of Science, and Embase were searched from inception to August 26, 2025. Eligible randomized controlled trials included adult RA patients diagnosed according to American College of Rheumatology or European League Against Rheumatism criteria and compared curcumin in any formulation with placebo or standard care. Two independent reviewers conducted study selection, data extraction, and methodological quality assessment using the Cochrane Risk of Bias 2.0 tool. Pooled analyses were conducted using Review Manager, version 5.4 and Stata, version 18, with fixed-effect or random-effects models based on heterogeneity. Results: Seven randomized controlled trials were included. Curcumin significantly reduced Disease Activity Score in 28 joints (weighted mean difference [WMD] −1.47; 95% confidence interval [CI] −1.68 to −1.26), rheumatoid factor (WMD −24.15; 95% CI −36.47 to −11.83), erythrocyte sedimentation rate (WMD −31.26; 95% CI −58.59 to −3.93), and C-reactive protein (WMD −0.93; 95% CI −1.33 to −0.53). Substantial heterogeneity was observed; nevertheless, leave-one-out sensitivity analyses confirmed stability of pooled estimates, and Egger tests revealed no significant publication bias. Conclusion: Curcumin supplementation was associated with statistically and clinically relevant improvements in disease activity and systemic inflammatory markers in RA. These findings support curcumin as a promising adjunctive therapeutic strategy, though larger, exposure-verified trials with extended follow-up remain required to validate long-term treatment effects and inform clinical implementation.