Background: Existing meta-analyses on omega-3 polyunsaturated fatty acids and their anti-inflammatory effects have reported uncertain findings. The current umbrella meta-analysis aimed to assess the findings of multiple meta-analyses on the efficacy of n-3 PUFAs on inflammatory biomarkers in adults with different health conditions.

Methods: Using suitable keywords, articles published until December 2021 were searched in PubMed/Medline, Web of Science, Scopus, EMBASE, and Google Scholar. Meta-analyses investigating the impact of supplementation of n-3 PUFAs on inflammatory biomarkers in adults were included. We performed this meta-analysis using a random-effects model.

Results: Overall, 32 meta-analyses were qualified in this umbrella meta-analysis. Our findings demonstrated that the n-3 PUFA supplementation significantly reduced serum C-reactive protein (CRP) (ES = -0.40; 95 % CI: -0.56, -0.24, p < 0.001; I² = 89.5 %, p < 0.001), Tumour necrosis factor α (TNFα) (ES = -0.23; 95 % CI: -0.37, -0.08, p = 0.002; I² = 60.1 %, p < 0.001), and interleukin 6 (IL-6) concentrations (ES = -0.22; 95 % CI: -0.39, -0.05, p = 0.010; I² = 66.2 %, p < 0.001).

Conclusion: The current umbrella meta-analysis found that supplementation of n-3 PUFAs in adults can improve CRP, TNF-α, and IL-6 concentrations under various health conditions. n-3 PUFAs can be recommended as adjuvant anti-inflammatory agents.