Adding fish oil supplements to the diet can prevent the constriction of the airways brought on by exercise in asthmatics, a very common problem in this patient group, new research shows.

In an earlier study, Dr. Timothy D. Mickleborough, from Indiana University in Bloomington, and colleagues had shown that fish oil supplements can improve lung function in elite athletes with bronchoconstriction (EIB), but their use in asthmatics with the condition had not been well studied.

“The current findings suggest that fish oil supplements may be of value to asthmatics with EIB,” Mickleborough told Reuters Health. “Our results support previous reports suggesting that the benefits are mediated through the antiinflammatory effects of fish oil.”

The researchers assessed pre- and postexercise lung function and sputum inflammatory markers in 16 asthma patients with EIB who were randomly assigned to a normal diet supplemented with fish oil capsules or with placebo for three weeks. After a two-week interval, in which no supplements or placebos were given, the patients switched to the other regimen.

With the normal diet alone as well as the placebo-supplemented diet, the participants developed EIB. By contrast, with fish oil supplementation, the decrease in lung function that occurred with exercise was smaller and did not reach the threshold needed for an EIB diagnosis. In addition, with the supplements, the subjects were able to cut back on bronchodilator usage.

Compared with the other diets, the fish oil-supplemented diet was associated with a significant drop in a number of markers of inflammation in the sputum, which was noted both before and after exercise.

Mickleborough said the study subjects received 20 capsules of fish oil per day, in keeping with the dose his team had used in their earlier study, and suspects this may make patients less compliant. However, he hopes to conduct a dose-finding study in the future, which could result in the use of a much smaller dose.

SOURCE: Chest January 2006.