Omega-3 supplements for patients in chemotherapy and/or radiotherapy: A systematic review

Background & aims: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in vitro and in vivo, used along with anticancer drugs, have improved cancer treatment outcome. Clinical studies have reported positive results with omega-3 supplements in oncologic patients. We summarized only randomized controlled clinical trials involving the administration of DHA and/or EPA during chemotherapy and/or radiotherapy to assess the effects on treatment outcomes.

Methods: We conducted a systematic literature search using specific terms. Of 157 publications, 10 were selected on the basis of their methodological quality, according to the Oxford Quality Scale and the Cochrane Concealment Assessment. Outcome included body weight and composition, peripheral neuropathy, immune, inflammatory and oxidative status, quality of life, and membrane omega-3 fatty acids incorporation.

Results: Treatment regimens included radiotherapy (1), chemotherapy (8), and chemoradiotherapy (1). The number of patients ranged from 11 to 92 and the daily dose of EPA and/or DHA from 600 mg to 3.6 g. For high quality methodology studies only, the combination of omega-3 fatty acids supplements with conventional chemotherapy was beneficial. None of the studies reported a worse outcome for the supplement patients.

Conclusions: There are beneficial effects of omega-3 fatty acids supplements in patients undergoing chemotherapy and/or radiotherapy on different outcomes, being the preservation of body composition the most evident. Some important outcome like decrease tumor size and prolonging patient survival, are not observed.