Fish Oil Reduces Asthma in Athletes

Athletes who experience shortness of breath and other asthma-like symptoms after exercise may benefit from fish oil capsules, researchers report in the November 2003 issue of the American Journal of Respiratory and Critical Care Medicine. In a small study, elite athletes who normally experienced asthma-like symptoms after exercising had less severe symptoms after adding fish oil capsules to their diet.

"If you experience asthma-like symptoms after exercise, such as breathlessness and a tight chest, then taking fish oil supplements that contain omega-3 fatty acids may help you breathe better during and after exercise," said Dr. Timothy D. Mickleborough of Indiana University in Bloomington.

For many people with asthma, exercise can trigger wheezing, chest tightness, cough and breathlessness, but these symptoms may also occur in people who do not have asthma. In fact, research suggests that elite athletes are more likely to experience asthma-like symptoms after exercise than less accomplished athletes and the general population. Why this is the case is uncertain, but prolonged exercise may increase exposure to allergens and substances that can irritate the airways as well as increase inhalation of cold, dry air.

Because substances called omega-3 polyunsaturated fatty acids (PUFAs) that are found in fish oils can produce anti-inflammatory effects, there has been interest in seeing whether PUFAs may improve asthma symptoms.

So far, the evidence on the effect of PUFAs in people with asthma is mixed and the one study that looked at the effect of fish oil supplements on asthma did not show any benefits. Now, in a study that tested the effect of fish oil supplements in athletes with exercise-induced asthma-like symptoms, Mickleborough and his colleagues report that fish oils seem to reduce the severity of symptoms.

The study included 20 elite athletes, half of whom experienced asthma-like symptoms after exercise but who did not have asthma. For three weeks, participants were randomly assigned to take fish oil capsules or placebo capsules that contained olive oil. After a two-week washout period, volunteers switched groups. Before exercise, there were no significant differences in lung function between the fish oil and placebo groups,

But the decline in lung function that normally occurred after exercise was reduced by almost 80 percent in athletes on the fish oil diet. These athletes also needed less asthma medication when taking fish oil supplements. Fish oil supplements did not seem to affect lung function at all in athletes who did not usually experience symptoms after exercise. The authors of a related editorial caution that the study was small and does not mean that fish oil supplements will help people with asthma.

Reference:

American Journal of Respiratory and Critical Care Medicine, November 15, 2003.

Key concepts: Fish oil, omega-3 fatty acids, PUFA, asthma, athletes