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-α, interleukin-1β, 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.