The study looked at 40 people with lung cancer during the approximately 10-week duration of their initial chemotherapy. The 16 patients who took 2.2 grams a day of eicosapentaenoic acid (EPA), an omega-3 fatty acid found in fish oil, maintained their weight, while the 24 people not on the pills lost an average of 5 pounds. Moreover, 69 percent of patients in the fish oil group maintained or gained muscle mass compared with only 29 percent of patients in the standard care group.

Bottom line: While it's still unclear how fish oil helps maintain weight and strength,  chemotherapy patients might want to talk with their oncologist about the finding to see if taking the supplements makes sense for them, especially if they've experienced weight loss or declining strength.

--Doug Podolsky, senior editor

See more on lung-cancer screening and treatment.