January 9, 2006

Fish oil can prevent airway constriction in asthma

By Anthony J. Brown, MD

NEW YORK (Reuters Health) - 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

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.