The effects of supplementation of n-3 polyunsaturated fatty acids on clinical outcome parameters in patients with cancer: a systematic review

Abstract

Introduction Existing guidelines on nutrition support in patients with cancer cachexia state limited evidence for the beneficial effects of n-3 polyunsaturated fatty acids (PUFAs) on clinical outcome. In order to report on the latest evidence for n-3 PUFAs in cancer cachexia, we conducted a systematic literature review of randomized controlled trials (RCTs), comparing the effects on clinical outcome parameters of oral or enteral supplementation of n-3 PUFAs in cancer patients receiving chemotherapy, radiotherapy, surgery or palliative care. Method In PubMed[©], EMBASE and the Cochrane Library, search terms on cancer, n-3 PUFAs and clinical outcome parameters (nutritional status, morbidity, mortality and quality of life) were entered on 1 April 2013, using limits for adults, humans and English language. The quality and evidence of the retrieved publications were appraised by an expert team of Australian and Dutch dieticians and nutritionists, using the ADA grading system. Fifteen RCTs were retrieved. Results Nine RCTs were of positive quality, five of neutral quality and one of negative quality and were performed in patients with various types of cancer. Fair evidence shows that supplementation of n-3 PUFAs appears to be safe and may improve the quality of life and physical activity in patients with cancer. However, supplementation of n-3 PUFAs does not improve energy or protein intake, appetite or survival and does not reduce postoperative complications. The evidence for the effect on body weight, fat-free mass and performance status remains inconclusive. Conclusion Supplementation of n-3 PUFAs may have some positive effects in patients with cancer