Effect of Marine-Derived n-3 Polyunsaturated Fatty Acids on Major Eicosanoids: A Systematic Review and Meta-Analysis from 18 Randomized Controlled Trials

Background

Marine-derived n-3 polyunsaturated fatty acids (PUFA) may have a beneficial effect on inflammation via lowering pro-inflammatory eicosanoid concentrations. We aimed to assess the effect of marine-derived n-3 PUFA on prostaglandin E₂ (PGE₂), thromboxane B₂ (TXB₂), and leukotriene B₄ (LTB₄) through systematic review and meta-analysis of randomized controlled trials.

Method and Findings

A structured search strategy on PubMed, Web of Science and Cochrane up to November 2015 was undertaken in this meta-analysis. Standard mean difference was used to calculate the effect size of marine-derived n-3 PUFA on PGE₂, TXB₂ and LTB₄ in a random-effect model. A total of 18 RCTs with 826 subjects were included in this systematic review and meta-analysis. Supplementation of marine-derived n-3 PUFA significantly decreased concentrations of TXB₂ in serum/plasma in subjects with high risk of cardiovascular diseases (SMD:-1.26; 95% CI: -1.65, -0.86) and LTB₄ in neutrophils in unhealthy subjects (subjects with non-autoimmune chronic diseases or auto-immune diseases) (SMD:-0.59: 95% CI: -1.02, -0.16). Subgroup analyses showed a significant reduction of LTB₄ in subjects with rheumatoid arthritis (SMD: -0.83; 95% CI: -1.37, -0.29), but not in non-autoimmune chronic disease patients (SMD: -0.33; 95% CI: -0.97, 0.31). No significant publication bias was shown in the meta-analysis.

Conclusions

Marine-derived n-3 PUFA had a beneficial effect on reducing the concentration of TXB₂ in blood of subjects with high risk of CVD as well as LTB₄ in neutrophils in unhealthy subjects, and that subjects with RA showed lower LTB₄ content with supplementation of marine-derived n-3 PUFA.