Fish oil may help to prevent the severe wasting and weight loss (cachexia), which characterizes some types of advanced cancer, suggests research in the medical journal Gut. Cachexia is a major factor contributing to the illness and death of patients with advanced cancer, as a result of the changes in metabolism and loss of appetite created by the disease.

The research team divided 200 patients with pancreatic cancer into two groups: 105 were given a high calorie, high protein supplement; and 95 were given an energy dense, high protein supplement enriched with omega-3 essential fatty acid and vitamins E and C. Omega 3 essential fatty acids are found in fatty fish, such as herring and salmon. The study lasted eight weeks.

The researchers found that, on average, patients had lost 17% of their body weight and were losing over 3 kilos of weight a month before they started taking the supplements. After eight weeks, weight loss had stopped in both groups. They found that there was a direct and significant correspondence between the amount of fish oil enriched supplement patients consumed and the amount of weight and muscle bulk (lean body mass) gained. This was not seen among those patients taking the supplement without the added fish oil, suggesting that it is this component that is therapeutic. The patients taking the oil enriched supplement also reported a significantly improved quality of life.

The authors conclude that further research is needed to confirm their findings, but suggest that nutritional supplements enriched with omega 3 essential fatty acids may be a promising treatment for cancer cachexia.