Effect of omega-3 fatty acids supplementation on adipokines: a systematic review and meta-analysis of randomized controlled trials

Abstract

Background

Although a large body of literature reported the beneficial effects of omega-3 fatty acids (omega-3 FAs) consumption on adipokines levels, but recent findings from clinical trials are not univocal. The aim of this systematic review and meta-analysis was to evaluate the effect of omega-3 FAs supplements on adipokines.

Methods

We searched Medline, Web of Science, Scopus, Embase, and Cochrane Library from inception to August 2020 without any particular language limitations. Outcomes were summarized as standardized mean difference (SMD) with 95% confidence intervals (CIs) estimated from Hedge's g and random effects modeling.

Results

Fifty-two trials involving 4,568 participants were included. Omega-3 FAs intake was associated with a significant increase in plasma adiponectin levels (n = 43; 3,434 participants; SMD: 0.21, 95% CI: 0.04, 0.37; p = 0.01; I²= 80.14%). This meta-analysis indicates that supplementing participants with omega-3 fatty acids more than 2000 mg daily and more than 10 weeks resulted in a significant and more favorable improvement in plasma adiponectin levels. However, omega-3 FAs intake had no significant effect on leptin levels (SMD: −0.02, 95% CI: −0.20, 0.17, I²= 54.13%).

Conclusion

The evidence supports a beneficial effect of omega-3 FAs intake on serum adiponectin levels but does not appear to impact on leptin concentrations. Larger well-designed RCTs are still required to evaluate the effect of omega-3 FAs on leptin in specific diseases.

Graphical Abstract

Keywords:

• Adipokines
• adiponectin
• meta-analysis
• omega-3 FAs
• leptin
• systematic review

Disclosure statement

The authors have no conflict of interest to declare.

Statement of ethics

This systematic review is accordance with the World Medical Association Declaration of Helsinki.

Author contributions

J.H. and M.S. contributed to the study design and interpretation; and drafted and edited the manuscript. M.M., M.D.E. and M.Q. contributed to the statistical analysis and edited the draft. D.M.R., GH.R. and F.F. contributed to interpretation of the work and revised it critically for important intellectual content. S.E. and F.SH. contributed to performing search and data collection. J.H. and M.S. contributed to edited manuscript and preparing the final article version. H.H. and GH.R. contributed to the revision of the manuscript.