It has been suggested that n–3 (omega-3) polyunsaturated fatty acids (PUFAs) may have beneficial effects in patients with cancer or in patients who undergo surgery or critical care. The authors of this article systematically reviewed the effects of oral or enteral and parenteral n-3 FA supplementation on clinical outcomes in such patients. They only included randomised controlled trials which studied the supplementation of oral or enteral and parenteral n-3 FA. A secondary part of the review investigated the incorporation of n-3 FAs into phospholipids of plasma, blood cells, and mucosal tissue and the subsequent washout in these patients. The authors included controlled and non-controlled studies for this part of the research. The results found (direct from source):

• 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. The authors did not find any studies on parenteral supplementation of n−3 FAs in cancer.

• In surgical oncology, they did not find any studies on enteral supplementation of n−3 FAs. However, the authors note that postoperative parenteral supplementation in surgical oncology may reduce the length of a hospital stay.

• No studies were found on enteral supplementation of n−3 FAs for general surgery 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 days) than with parenteral supplementation (1–3 days). The washout was 5–7 days.

The authors discuss the strengths and limitations of their research and conclude, “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.”