Profiling Inflammatory Biomarkers following Curcumin Supplementation: An Umbrella Meta-Analysis of Randomized Clinical Trials.

Objective: Several meta-analyses have shown that curcumin can reduce inflammatory biomarkers, but the findings are inconsistent. The objective of the present umbrella meta-analysis was to provide a more accurate estimate of the overall effects of curcumin on inflammatory biomarkers.

Methods: The following international databases were systematically searched until March 20, 2022: PubMed, Scopus, Embase, Web of Science, and Google Scholar. A random-effects model was applied to evaluate the effects of curcumin on inflammatory biomarkers. Meta-analysis studies investigating the effects of curcumin supplementation on inflammatory biomarkers with corresponding effect sizes (ES) and confidence intervals (CI) were included in the umbrella meta-analysis. GRADE (Grading of Recommendations Assessment, Development, and Evaluation) was used to evaluate the certainty of evidence.

Results: A meta-analyses of ten studies with 5,870 participants indicated a significant decrease in C-reactive protein (CRP) (ES = -0.74; 95% CI: -1.11, -0.37, < 0.001; I = 62.1%, =0.015), interleukin 6 (IL-6) (ES = -1.07; 95% CI: -1.71, -0.44, < 0.001; I = 75.6%, < 0.001), and tumour necrosis factor (TNF-) levels (ES: -1.92, 95% CI: -2.64, -1.19, < 0.0; I = 18.1%, =0.296) following curcumin supplementation. Greater effects on CRP and TNF- were evident in trials with a mean age >45 years and a sample size >300 participants.

Conclusion: The umbrella of meta-analysis suggests curcumin as a promising agent in reducing inflammation as an adjunctive therapeutic approach in diseases whose pathogenesis is related to a higher level of inflammatory biomarkers.