Current studies on inhibitory effects of omega-3 polyunsaturated fatty acids (PUFAs) on pro-inflammatory cytokines have inconsistent results. Thus, a meta-analysis of randomised controlled trials (RCTs) was conducted to identify the effects of omega-3 PUFA administration on circulating interleukin-6 (IL-6) and tumor necrosis factor (TNF) in patients with cancer. Studies that examined the effects of omega-3 PUFA administration on circulating IL-6 and TNF in patients with cancer were identified by searching PubMed and EMBASE from January 1975 to February 2021. Differences in omega-3 PUFA administration and control conditions were determined by calculating standardised mean differences (SMDs) with 95% confidence intervals (CIs). Twenty studies involving 971 patients met the inclusion criteria. The overall SMDs were 0.485 (95% CI: 0.087-0.883) for IL-6 and 0.712 (95% CI: 0.461-0.962) for TNF between omega-3 PUFA administration and control conditions. Sources of heterogeneity were not found through subgroup and meta-regression analyses. Publication bias was observed in TNF with a slight contribution to the effect size. Omega-3 PUFAs can reduce circulating IL-6 and TNF levels in patients with cancer. Results supported the recommendation of omega-3 PUFAs as adjuvant therapy for patients with cancer, possibly excluding head and neck cancer, owing to their anti-inflammatory properties.
Omega-3 Polyunsaturated Fatty Acids can Reduce IL-6 and TNF Levels in Patients with Cancer