N - 3 fatty acids during chemotherapy: toward a higher level of evidence for clinical application.

Purpose of review Recommendations for intakes of n - 3 fatty acids (FAs) in patients who are receiving chemotherapy for cancer are based on weak evidence. This review highlights themes within the emergent literature to suggest improvements in the design of studies that provide n - 3 FA supplements concurrent with cytotoxic agents. Recent findings Following earlier research in animal models and human pilot studies, recent human studies have evaluated the effect of providing n - 3 FAs during delivery of single agent and multiagent chemotherapy regimens for breast and gastro-intestinal cancers. Regimens were based on platinum compounds, fluoropyrimidines or both, and a variety of additional agents. Tumor location and stage, supplement dose and duration, and endpoints were dissimilar across studies. Overall, the recent research continues to support the safety and tolerability of n - 3 FA supplementation with chemotherapy and provides additional evidence, albeit weak, for enhanced tumor response, maintenance of weight and muscle, and reduction in inflammation and toxicities in the host across multiple cancer sites and chemotherapy regimens. The barriers to implementation in practice remain small study sizes, variations in supplement dosage and methodology, and differences in primary endpoints. Randomized, blinded trials with a justifiable sample size, adequate doses, monitored compliance and measures of clinically important endpoints are required to move these findings to a higher level of evidence for implementation into clinical practice.