March 1, 2011 — Fish oil may counter weight loss in cancer patients undergoing chemotherapy, according to a new study published in the online edition of the journal Cancer.

In the study, researchers at the University of Alberta in Edmonton, Canada, enrolled 40 patients with non-small-cell lung cancer. They were all in the early stages of treatment. Sixteen of those patients took 2.2 grams of fish oil per day, while the remaining 24 received standard care. The study, which lasted about 10 weeks, ran until the patients completed their initial chemotherapy treatments.

The majority of patients in the study who supplemented their diet with fish oil, which is rich in omega-3 fatty acids, either maintained or gained weight. Weight loss is a common side effect of chemotherapy, as patients often lose their appetite. Chemotherapy can also affect a person’s sense of taste, dulling the flavor of foods and making them less appealing. Poor nutritional intake in turn can lead to fatigue, reduced quality of life, and worsening health.

Fish Oil Better Than Standard Care

Sixty-nine percent of the patients given fish oil maintained their weight. Some even gained weight. Less than a third of the patients in the other group kept their weight up. Instead, they lost an average of 2.3 kilograms (about 5 pounds) over the course of the study. Most of the patients taking fish oil also maintained muscle mass for the duration of the study, while the majority of those receiving standard care lost a significant amount of muscle mass.

Previous studies of fish oil’s role in weight maintenance focused on patients with advanced cancers, the study authors write. This study was unique in that it followed newly referred patients. Early intervention to prevent weight loss and related side effects may improve patients’ outcomes and their eligibility for a greater number of cancer treatments, study authors say. However, they say larger, randomized trials need to be conducted to verify their results.

“This holds great promise because currently there is no effective treatment for cancer-related malnutrition,” study co-author Vera Mazurak, PhD, says in a statement.