Meta-analysis of omega-3 polyunsaturated fatty acids on immune functions and nutritional status of patients with colorectal cancer

Systematic review and meta-analysis of 20 randomized controlled trials in postoperative colorectal cancer patients after radical surgery. The omega-3 PUFA active arm included 809 participants, with comparisons made against control groups receiving standard nutrition or other comparators as defined in the included trials.

Omega-3 polyunsaturated fatty acids were evaluated as postoperative immunonutrition in patients with colorectal cancer after radical surgery. The supplementation was given through enteral nutrition in 4 trials and parenteral nutrition in 16 trials; the specific dose, form, and duration were not reported in the source packet.

Omega-3 PUFA supplementation was associated with improved immune function and nutritional status after radical colorectal cancer surgery. Pooled effects favored omega-3 PUFAs for IgA (SMD = 0.54; 95% CI 0.10-0.99), IgM (SMD = 0.52; 95% CI 0.05-0.99), CD4+ (SMD = 0.76; 95% CI 0.53-0.98), CD4+/CD8+ (SMD = 0.66; 95% CI 0.39-0.92), total protein (SMD = 0.53; 95% CI 0.17-0.88), albumin (SMD = 0.43; 95% CI 0.15-0.70), and prealbumin (SMD = 0.46; 95% CI 0.01-0.90). The review concluded that omega-3 PUFAs may be an effective immunonutritional therapy in this setting, although the evidence quality was low to moderate.

Evidence quality was generally low to moderate because of methodological heterogeneity and potential bias across trials. Dosing and regimen details were not reported in the extracted source, and long-term high-dose safety remains a concern because gastrointestinal disturbance, bleeding, and other adverse reactions were noted in the discussion. Some reported outcome statistics were internally inconsistent in the source packet, which further limits certainty.