Objective: To evaluate systematically the clinical efficacy of omega-3 polyunsaturated fatty acids (PUFAs) in the prevention of postoperative complications in colorectal cancer (CRC) patients.

Materials and methods: Published articles were identified by using search terms in online databases – PubMed, Embase, and the Cochrane Library – up to March 2016. Only randomized controlled trials investigating the efficacy of omega-3 PUFAs in CRC were selected and analyzed through a meta-analysis. Subgroup, sensitivity, and inverted funnel-plot analyses were also conducted.

Results: Eleven articles with 694 CRC patients were finally included. Compared with control, omega-3 PUFA-enriched enteral or parenteral nutrition during the perioperative period reduced infectious complications (risk ratio [RR] 0.63, 95% confidence interval [CI] 0.47–0.86; P=0.004), tumor necrosis factor alpha (standard mean difference [SMD] -0.37, 95% CI -0.66 to -0.07; P=0.01), interleukin-6 (SMD -0.36, 95% CI -0.66 to -0.07; P=0.02), and hospital stay (MD -2.09, 95% CI -3.71 to -0.48; P=0.01). No significant difference was found in total complications, surgical site infection, or CD4+:CD8+ cell ratio.

Conclusion: Short-term omega-3 PUFA administration was associated with reduced postoperative infectious complications, inflammatory cytokines, and hospital stay after CRC surgery. Due to heterogeneity and relatively small sample size, the optimal timing and route of administration deserve further study.

Keywords: omega-3, fatty acids, fish oil, colorectal surgery, meta-analysis