Effects of parenteral ω-3 fatty acid supplementation in postoperative gastrointestinal cancer on immune function and length of hospital stay: a systematic review and meta-analysis

Background and Objectives: Omega-3 fatty acids are widely used in nutritional support. However, whether parenteral supplementation with omega-3 fatty acids is effective for gastrointestinal cancer patients remains uncertain. This study assessed the effects of this form of parenteral nutrition on immune function and clinical outcomes in postoperative gastrointestinal cancer patients. Methods and Study Design: We searched Medline, Embase, Scopus, and the reference lists of selected studies to identify randomized controlled trials that compared omega-3 fatty acids with a control, and that included immune indices, infectious complications, or length of hospital stay in the final outcomes. The odds ratio and weighted mean difference with 95% confidence intervals were calculated and the I-2 statistic was used to assess heterogeneity. Results: Seven trials with a total of 457 participants were included in the meta-analysis. Five pooled trials with 373 participants indicated that the incidence of infectious complications was significantly different between the intervention and control groups (odds ratio: 0.36; 95% confidence interval: 0.18, 0.74, p<0.05). Five trials involving 385 participants indicated that parenteral omega-3 fatty acid supplementation significantly shortened the length of hospital stay (weighted mean difference: -2.29, 95% confidence interval: -3.64, -0.93; p<0.05). Meta-analysis also indicated that omega-3 fatty acids increased the level of CD4(+) and CD4(+)/CD8(+) ratio. Conclusions: The results of this study suggest that parenteral omega-3 fatty acid supplementation is beneficial for gastrointestinal cancer patients, and is accompanied by improved postoperative im-mune function and satisfactory clinical outcomes.