Fish oil may help cancer patients’ fight muscle wastage, say researchers
The study, published in Cancer, found that patients supplemented with 2.2 grams of eicosapentaenoic acid (EPA) per day maintained weight, muscle mass, and adipose tissue throughout approximately 10 weeks of chemotherapy, despite having a mean weight loss of 6.3 percent over the previous 6 months.
In the same time, patients receiving standard treatment with no supplementation were found to loose an average of 2.3 kilograms.
“Fish oil may prevent loss of weight and muscle by interfering with some of the pathways that are altered in advanced cancer … This holds great promise because currently there is no effective treatment for cancer-related malnutrition,” said Dr. Vera Mazurak, from the University of Alberta, Canada, who led the study.
The researchers said that a nutritional intervention with two grams of fish oil (in the form of EPA) per day may provide a benefit over standard care, by allowing cancer patients to maintain weight and muscle mass during chemotherapy.
Omega-3 for the big C?
Chemotherapy can cause cancer patients to lose muscle mass and become malnourished, leading to fatigue, decreased quality of life, an inability to receive necessary treatments, and shorter survival.
The researchers explained that previous studies have suggested that supplementing the diet with fish oil - which contains omega-3 fatty acids such as eicosapentaenoic acid (EPA) - may help patients maintain or gain muscle mass.
To test the theory the team compared the effects of fish oil with that of standard care (with no supplementation) on weight, muscle, and fat tissue in newly referred non-small cell lung cancer patients.
Computed tomography (CT), a form of medical imaging that can precisely quantify skeletal muscle, was used by the researchers to assess the effects of EPA supplementation on skeletal muscle in patients undergoing chemotherapy.
“The efficacy of fish oil to prevent muscle loss has been the focus of several studies, but to the best of our knowledge the current study is the first to use CT images to provide a direct measurement of the effect of fish oil on skeletal muscle and adipose tissue depots,” said the researchers.
They added that the study was also unique in using an early intervention in newly referred patients –with the goal of preventing weight and muscle loss during chemotherapy.
Mazurak and her colleagues reported that 40 patients completed the study; with 16 receiving EPA fish oil supplementation (at a dose of 2.2 grams of EPA per day), and 24 patients receiving standard care.
Skeletal muscle and adipose tissue were measured using CT images, whilst blood was collected and weight was recorded at baseline and throughout chemotherapy.
The authors reported that patients receiving standard care experienced an average weight loss of 2.3 kilograms, whereas patients receiving EPA supplementation maintained their weight.
Blood analyses revealed that the patients with the largest rise in bloodstream EPA concentrations also had the greatest muscle mass gains.
Mazurak and co-workers reported that nearly 70 percent of those in the fish oil group either maintained their pre-chemotherapy muscle mass or gained mass. By comparison, less than 30 percent of the non-fish oil group maintained their original muscle mass, they added.
They research team said the results of the study indicate that supplementation with EPA fish oil reduces muscle and adipose tissue wasting in lung cancer patients, and provides a benefit over patients treated with standard care and receiving chemotherapy.
Mazurak and her colleagues noted that fish oil may be beneficial to patients with other forms of cancer and other chronic diseases that are associated with malnutrition, as well as to elderly individuals who are at risk for muscle loss. However, they noted that the results of the current study “require verification in larger randomized trials.”
Published online ahead of print, doi: 10.1002/cncr.25933
“Supplementation with fish oil increases first-line chemotherapy efficacy in patients with advanced nonsmall cell lung cancer”
Authors: R.A. Murphy, M. Mourtzakis, Q.S.C. Chu, V.E. Baracos, T. Reiman, V.C. Mazurak