Impact of fish oil and melatonin on cachexia in patients with advanced gastrointestinal cancer: a randomized pilot study

OBJECTIVE: The effect of fish oil (FO), melatonin (MLT), or their combination and dietary advice on cachexia and biochemistry variables reflecting cachexia were investigated in patients with advanced gastrointestinal cancer. METHODS: Twenty-four patients not amenable to standard anticancer treatment and with documented weight loss and/or decreased serum albumin were included. They were randomized to 30 mL/d of FO, which provided 4.9 g of eicosapentaenoic acid and 3.2 g of docosahexanoic acid, or 18 mg/d of MLT for 4 wk. During the next 4 wk, all patients had FO and MLT. Serum or plasma was analyzed for tumor necrosis factor-alpha, interleukin-1beta, soluble interleukin-2 receptor, interleukin-6, and interleukin-8 and the fatty acids eicosapentaenoic acid, docosahexanoic acid, arachidonic acid, and linoleic acid. RESULTS: Serum levels of eicosapentaenoic acid and docosahexanoic acid increased as expected with FO. No major changes in biochemical variables and cytokines were observed with any intervention. In the FO group, 5 of 13 patients (38%) showed weight stabilization or gain compared with 3 of 11 patients (27%) in the MLT group. After combining interventions, approximately 63% of patients showed such responses. CONCLUSIONS: FO, MLT, or their combination did not induce major biochemical changes indicative of a strong anticachectic effect. Nonetheless, the interventions used may have produced a weight-stabilizing effect.