n-3 polyunsaturated fatty acids: the potential role for supplementation in cancer

n-3 polyunsaturated fatty acids, eicosapentaenoic acid and docosahexaenoic acid have been implicated as potential mediators in pathways involved in cancer cachexia. This review summarizes recent findings on the n-3 fatty acid status of patients with cancer, the effects of n-3 fatty acid supplementation on weight and lean body mass and the potential role of supplementation during antineoplastic therapy.

Due to suboptimal intakes and possible metabolic disturbances, physiological concentrations of n-3 fatty acids are low in patients with cancer. Low n-3 fatty acids are associated with loss of skeletal muscle, suggesting a need for supplementation. Recent trials have shown an effect of n-3 supplementation throughout antineoplastic therapy on weight, lean body mass and treatment outcomes. Attenuation or gain of weight and lean body mass was reported and the first clinical trials of n-3 fatty acids as an adjuvant to chemotherapy treatment suggest improved efficacy and milder treatment toxicity with n-3 fatty acid supplementation.

Recent evidence appears to favour providing n-3 fatty acids early in the disease trajectory, during antineoplastic therapy for preservation of muscle and also to improve treatment tolerance. Additional, larger trials are needed to define these relationships further but it appears that fish oil has broad therapeutic potential in patients with cancer.