
Going through cancer chemotherapy is challenging both mentally and physically – and it has a multitude of side effects including changes in body weight. Some people put on weight during their treatment, while others experience the opposite – chemotherapy weight loss – which may be substantial in some people.
Some people with a cancer diagnosis are already so thin from the ravishing effects of the cancer on their body that further weight loss could be dangerous. Some people with chemo weight loss have significant muscle mass, which contributes to their weakness and fatigue and makes their recovery even more challenging. People on chemotherapy may lose weight because of a lack of appetite or from the nausea and vomiting they experience.
Could there be a natural way to treat chemotherapy weight loss? According to a new study published in the journal Cancer, taking fish oil supplements could help cancer patients halt some of the muscle loss they experience during this challenging time in their life.

Fish Oil and Weight Gain during Chemotherapy
Researchers at the University of Alberta in Canada looked at the role of fish oil for offsetting chemotherapy weight loss. They gave 16 cancer patients 2.2 grams of EPA (a type of omega-3 in fish oil) during their ten week course of cancer chemotherapy. Another 24 cancer patients didn’t receive EPA or any other fish oil during their therapy.
During the study, researchers measured their fat and muscle using CT imaging. With the help of this imaging modality, they found almost 7 out of 10 of the patients in the fish oil group maintained or increased their muscle mass during chemo, while 7 out of 10 in the non-fish oil group lost muscle mass. Good news for those who supplement with fish oil.
Cancer and Weight: Fish Oils to the Rescue
There’s more good news for cancer patients who take fish oil supplements. Scientists at the University of Texas Science Health Center believe that fish oil makes cancer cells more sensitive to the effects of cancer chemotherapy – so the therapy is more effective.
The active ingredients in fish oil are added to the cell membranes of cancer cells, which make them more susceptible to the damaging effects of cancer chemotherapy, while normal cells remain unharmed. So fish oils may not only help with chemotherapy weight loss, but they may help with the destruction of cancer cells as well.
Chemo Weight Loss: The Bottom Line?
There may be benefits to taking fish oil supplements during cancer chemotherapy – not only to help preserve lean body mass but to make chemotherapy more effective. But always talk to your doctor before taking fish oil supplements. People on blood thinners or those at high risk for bleeding problems shouldn’t take them.
References:
Eurekalert.org. “Fish Oil Fights Weight Loss Due to Chemotherapy”
Charity Wire. “Fish Oil May Increase Effectiveness of Chemotherapy, Lessen Side Effects”