Effect of polyunsaturated fatty acids supplementation on nutritional status in patients with pancreatic cancer: a systematic review and meta-analysis

Background Patients with pancreatic cancer frequently experience malnutrition that is often unresponsive to conventional nutritional interventions. Objective To evaluate the impact of n-3 polyunsaturated fatty acids (PUFAs), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), supplementation on body weight (BW), lean body mass (LBM), body mass index (BMI), serum albumin (ALB), and serum prealbumin (PA) in this population. This systematic review was prospectively registered with PROSPERO (CRD42023402888). Methods Reviewers searched PubMed, Embase, Cochrane Library, Web of Science, Scopus, and ProQuest from inception to 31 January 2026. Risk of bias was assessed using the Cochrane Risk of Bias Tool (RoB 1.0). Statistical analyses were performed using RevMan 5.4. Certainty of evidence was evaluated using GRADEpro GDT. Results Nine randomized controlled trials (RCTs) were included and analyzed. Risk of bias was low in two studies, unclear in six, and high in one. The meta-analysis indicated that n-3 PUFAs may produce modest weight gain (SMD 1.41, 95% CI [0.36–2.46]; P = 0.008; low certainty, I 2 = 94%), though clinical significance is uncertain. No statistically significant effects were observed on LBM (SMD 0.21, 95% CI [−0.38–0.81]; P = 0.48; moderate certainty), BMI (WMD 0.59, 95% CI [−0.42–1.60]; P = 0.25; moderate certainty), ALB (SMD −0.07, 95% CI [−0.81–0.66]; P = 0.84; low certainty), or PA (SMD 0.13, 95% CI [−0.18–0.43]; P = 0.42; moderate certainty). Conclusion This meta-analysis suggests that n-3 PUFAs may produce modest weight gain, but evidence is insufficient to support meaningful improvement in overall nutritional status. Due to low certainty, substantial heterogeneity, and small sample sizes, recommendations remain individualized rather than routine. Well-designed, large-scale trials are needed to clarify which patients may benefit from this intervention.