Asthma, Author Interviews, CHEST, Omega-3 Fatty Acids / 23.01.2015
No Benefit of Omega-3 acid Supplements for Exercise-Induced Bronchoconstriction in Asthma
MedicalResearch.com Interview with:
John Brannan PhD
Firestone Institute for Respiratory Health at St Joseph’s Healthcare & McMaster University, Hamilton, Ontario, Canada
Medical Research: What is the background for this study?
Response: The use of omega-3 acid supplements as treatments for allergic diseases including asthma is controversial. Studies by investigators from Indiana University in the USA have repeatedly demonstrated a beneficial effect of high dose omega-3 fatty acid supplements over 3 weeks in attenuating exercise-induced bronchoconstriction (EIB) similar or possibly better in potency to what may be expected with a regular inhaled corticosteroids. The study by Brannan et al. attempted to validate these findings by using inhaled mannitol, a bronchial provocation test that was derived from the understanding of exercise-induced bronchoconstriction and which has demonstrated experimentally to be a useful model for exercise-induced bronchoconstriction. All pharmacotherapies that modify exercise-induced bronchoconstriction can modify the airway sensitivity to inhaled mannitol in persons with asthma, thus it was of interest to see if an 'alternative' treatment that demonstrated efficacy in exercise-induced bronchoconstriction could too modify the airway response to mannitol.
Medical Research: What are the main findings?
Response: The main findings were, to our surprise, there was no benefit of high dose omega-3 fatty acid supplements on bronchial hyperresponsiveness to mannitol over 3 weeks. This was associated with no changes in airway inflammation (sputum eosinophils), lung function or asthma symptom control. We also found no benefit on resting urinary mast cell metabolites, in contrast to the findings in studies showing a benefit of omega-3 fatty acids on EIB. Our findings suggest that omega-3 supplements in tissues may not be able to penetrate tissue and/or modify the substrate flow of eicosanoids in tissue such as the airways of the asthmatic. We did observed the expected reductions in blood triglycerides which suggests that these doses of omega-3s can modify metabolism in the blood or to some extent tissues that are highly perfused.

















