n-3 PUFAs in cancer, surgery, and critical care: a systematic review on clinical effects, incorporation, and washout of oral or enteral compared with parenteral supplementation.

BACKGROUND n-3 (omega-3) Fatty acids (FAs) may have beneficial effects in patients with cancer or in patients who undergo surgery or critical care. OBJECTIVE Our aim was to systematically review the effects of oral or enteral and parenteral n-3 FA supplementation on clinical outcomes and to describe the incorporation of n-3 FAs into phospholipids of plasma, blood cells, and mucosal tissue and the subsequent washout in these patients. DESIGN We investigated the supplementation of n-3 FAs in these patients by using a systematic literature review. RESULTS In cancer, the oral or enteral supplementation of n-3 FAs contributed to the maintenance of body weight and quality of life but not to survival. We did not find any studies on parenteral supplementation of n-3 FAs in cancer. In surgical oncology, we did not find any studies on enteral supplementation of n-3 FAs. However, postoperative parenteral supplementation in surgical oncology may reduce the length of a hospital stay. For general surgery, we did not find any studies on enteral supplementation of n-3 FAs, and evidence on parenteral supplementation was insufficient. In critical care, enteral supplementation of n-3 FAs had beneficial effects on clinical outcomes; evidence on parenteral supplementation in critical care was inconsistent. The incorporation of n-3 FAs in plasma and blood cells was slower with enteral supplementation (4-7 d) than with parenteral supplementation (1-3 d). The washout was 5-7 d. CONCLUSIONS This review shows the beneficial effects of n-3 FA supplementation in cancer, surgical oncology, and critical care patients. Supplementation in these specific patient populations could be considered with the route of administration taken into account.