Apart from reducing the risk of heart attacks and cardiovascular disease, diets high in fatty acids help prevent rheumatoid arthritis.

John Brannan wants to determine if there may be another benefit: combatting asthma.

He’s leading a new study at the Firestone Institute for Respiratory Research at St. Joseph’s Hospital that hopes to confirm a promising University of Indiana study that found high doses of omega-3 fatty acids had a “profound effect” in reducing exercise-induced asthma.

“Any drug that can inhibit exercise-induced asthma is a pretty good one,” says Dr. Brannan, who is visiting the institute from Sydney, Australia to conduct the study.

“This is quite important because basically everyone with asthma can develop exercise-induced asthma. It depends on whether they exercise or not and the type of exercise.”

Open to non-smokers aged 18 to 55, the Hamilton study will see 24 participants receive both a placebo and fish-oil supplements over two three-week periods, with a three-week cooling off period in between.

Neither Dr. Brannan nor participants will know which of the doses are being administered during each period to guard against bias, and to further mask the real dose, both the placebo and fish-oil supplements look identical and are vanilla flavoured.

Participants will receive four assessments. At the start of the study; after the first dose; when they return after three weeks to start the second phase; and at the end.

Dr. Brannan is still seeking participants but the study isn’t open to people with borderline or severe asthma.

The former have symptoms that are too suspectible to other factors while the latter might jeopardize their health, he says.

The goal is to see if the fish-oil supplements reduce two key symptoms of asthma: inflammation and the narrowing of airways.

To gauge the results, participants will undergo a series of lung tests, including to determine the presence of anti-inflammatory molecules omega-3 fats are thought to produce.

Another test will  analyze lung mucus, using the only machine of its kind in North America, one developed in Hamilton that Dr. Brannan likens to an expensive freezer.

The mucus will be assessed by a pathologist to characterize the type of inflammation in the participant’s airways.

“This is a new sort of frontier in asthma. There may be some evidence to suggest that not everyone’s asthma is the same,” Dr. Brannan says.

“Some people, depending on the type of inflammation they have, benefit from one medication more than the other.”

Although some of the lab equipment is leading-edge, Dr. Brannan says the suggestion that fish oil might prevent asthma “is not a terribly novel idea.”

A Nova Scotia study in the 1980’s, for instance, first postulated that the low prevalence of asthma, cardiovascular disease and rheumatoid arthritis among the Inuit was due to their high fish diet, he says.

Dr. Brannan says one theory for the rise in asthma elsewhere is the change in the ratio between fats that cause inflammation and those that prevent it: the ratio, about two or three to one a century ago, is now as high as 50 to one.

“There could be arguments against that as well,” Dr. Brannan says, acknowledging air pollution may be another factor.

“But it seems to have moved in parallel with some pretty dramatic changes in Western diets in a rather short space in time,” he says.

“One of the other theories is that we’re spending a hell of a lot of more time indoors these days, the sedentary lifestyle. There could be some side effects from that that we’re unable to understand fully. It could be a combination of factors.”

Dr. Brannan says research on the effects of omega-3 fats in fighting lung disease is mixed, with some showing benefits and some not.

But he says some of the studies haven’t been done properly, which may explain negative results.

“We’re doing it properly. We’re approaching this in a very thorough manner, and I’m hoping this opens a new, exciting area to study not just the omega-3’s, but some other alternative therapies that may have perhaps a supplementary effect.”

Dr. Brennan says although steroid inhalers these days are “remarkably safe” and vastly improved over their predecessors, the beauty of fish-oil supplements is that they’re natural and cheap.

Some people suffer side effects from steroids at higher doses, including bruising, water retention and more brittle bones, he says.

“This is a study that a drug company won’t support,” says Dr. Brannan, himself a long-time asthma sufferer.

“This is an internally funded study and interestingly enough, it’s one of the cheaper studies to come through the institute because it’s not a new medication. It’s fairly inexpensive to get your hands on.”

For more information on participating in the study, call Dr. Brannan at 905-522-1155 ext. 33584 or email him at brannan@mcmaster.ca.