The Effects of Omega-3 Fatty Acids Supplementation on Inflammatory Factors in Cancer Patients: A Systematic Review and Dose-Response Meta-Analysis of Randomized Clinical Trials

Abstract

Until now, no study evaluated the impact of optimum intake of omega-3 fatty acids on inflammatory factors. We aimed to investigate the dose-dependent effects of omega-3 fatty acids supplementation on inflammatory factors in cancer patients. PubMed, Scopus and ISI Web of Science were searched until July 2022 to find randomized controlled trials (RCTs) for examining the efficacy of omega-3 fatty acids on inflammatory factors. Our primary outcomes were interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), and albumin. The results of 33 trials (2068 participants) revealed that each 1 g/day omega-3 fatty acids (oral/enteral) significantly reduced IL-6 (SMD: −1.17 pg/ml; 95% CI: −1.78, −0.55; p < 0.001; GRADE = moderate), and TNF-α (SMD: −2.15 pg/ml; 95% CI: −3.14, −1.16; p < 0.001; GRADE = very low). Moreover, each 0.5 g/kg/day omega-3 fatty acids (parenteral) significantly reduced TNF-α (SMD: −1.11 pg/ml; 95% CI: −2.02, −0.19; p = 0.017; GRADE = low). With moderate and very low evidence certainty, each 1 g/day of omega-3 fatty acids supplementation (oral/enteral) has a beneficial effect on IL-6 and TNF-α. Each 0.5 g/kg/day omega-3 fatty acids (parenteral) could also exert a favorable impact on TNF-α, but the certainty of the evidence was low.

Author Contribution

The details of the authors’ responsibility in this project were as follows. RA, MHS, SZ.M, and LF collected and analyzed the data and wrote the initial version of the work. SW provided additional scientific analysis and reviewed and edited the manuscript. HM carefully read the text and tables and revised them. The final version was reviewed and approved by all authors.

Disclosure Statement

There was no conflict of interest in this project.

Data Availability Statement

The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Additional information

Funding

The project was funded by the Tehran University of Medical Sciences [code: 1401.-3-212-63133].