Fish Oil Supplementation for Anergia/Fatigue

Evidence in Specific Populations

Fish oil (2.2 g/day EPA) has shown benefits in reducing fatigue symptoms specifically in cancer patients undergoing chemotherapy, with maintained better body weight and reported less fatigue compared to control groups, as suggested by the ESPEN guidelines (weak recommendation, low evidence) 1, 2
The European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines suggest using long-chain N-3 fatty acids or fish oil supplementation in patients with advanced cancer undergoing chemotherapy to improve various symptoms including fatigue (weak recommendation, low evidence) 2

Fish oil contains omega-3 fatty acids (EPA and DHA) that have anti-inflammatory properties, with EPA being a competitive antagonist of N-6 arachidonic acid, which produces pro-inflammatory eicosanoids 1, 3

For potential clinical benefits, at least 2 g/day of omega-3 fatty acids appears to be required, with most studies showing benefits for fatigue using doses between 2-3 g/day 1, 2
Fish oil is generally well-tolerated at doses up to 5 g/day, with common side effects including mild gastrointestinal effects, fishy aftertaste, or fish-scented belching 3

Consider fish oil supplementation (2-3 g/day) for fatigue in patients with cancer undergoing chemotherapy, as recommended by the European Society for Clinical Nutrition and Metabolism (ESPEN) 1, 2
The American Heart Association recommends consuming fish as part of a healthy diet (2-3 servings/week) for general health benefits, and fish oil supplementation may be considered as an adjunct to fish intake for those who do not consume fish regularly 4

Fish oil supplementation is generally well-tolerated with minimal side effects, and despite theoretical concerns, long-term supplementation with EPA and DHA up to 5 g/day does not appear to increase bleeding risk 3
Potential contaminants in fish (mercury, persistent organic pollutants) should be considered, especially for pregnant women, as noted by the American Heart Association 4