Asthma is a common, complex disease of the bronchial airways that involves diverse underlying inflammatory mechanisms and clinical phenotypes. Obesity and adolescent age are both risk factors for poor asthma symptom control.
A diet low in fresh vegetables and fish and high in saturated fats and n-6 PUFA has been associated with both obesity and greater risk for asthma. Populations consuming high amounts of cold-water fish rich in long chains polyunsaturated fatty acids such as the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), traditionally have a low incidence of asthma.
A new study published online in the Annals of the American Thoracic Society, suggests that fish oil does not appear to improve asthma control in adolescents and young adults with uncontrolled asthma who are overweight or obese.
As usually recommended, four grams of fish oil a day for six months did not improve asthma control, as measured by a standard asthma control questionnaire, breathing tests, urgent care visits, and severe asthma exacerbations.
Jason E. Lang, MD, MPH said, “We don’t know why asthma control in obese patients is more difficult, but there is growing evidence that obesity causes systemic inflammation. Because the omega-3 fatty acids in fish oil have anti-inflammatory properties, we wanted to test whether fish oil would have therapeutic benefits for these patients.”
The 98 overweight/obese members in the investigation went in age from 12 to 25 (normal age: 14.6). All were determined to have asthma by a doctor yet had poor asthma control, in spite of utilizing a day by day inhaled corticosteroid to control their asthma.
About a large portion of the members was African American. For every three members doled out to take angle oil for 25 weeks, one was doled out to take the soy oil placebo.
Scientists also observed whether at whether a variant in the gene ALOX5 affected study findings. It is known that mutations in the gene can reduce responses to anti-leukotriene drugs.
Leukotrienes are inflammatory molecules that play a critical role in triggering asthma attacks. In this study, the ALOX5 variant did appear to be linked to leukotriene production but not to the effectiveness of fish oil in providing asthma control.
Scientists noted, “the study’s negative findings may not be the last word on fish oil and asthma. They acknowledged that larger doses of fish oil over a longer period of time may produce a different result.”
Dr. Lang said, “Based on the current study, however, “there is insufficient evidence for clinicians to suggest to patients with uncontrolled asthma that they should take daily fish oil supplements to help their asthma.”