An apple with your albuterol?

According to a study presented at the recent American Thoracic Society, people with asthma may be well-advised to avoid heavy, high-fat meals.

Individuals with asthma who consumed a high-fat meal showed increased airway inflammation just hours after the binge.  The high fat meal also appeared to inhibit the response to the asthma reliever medication albuterol.

“Subjects who had consumed the high-fat meal had an increase in airway neutrophils and TLR4 mRNA gene expression from sputum cells, that didn’t occur following the low fat meal,” said research fellow Dr. Lisa Wood, Ph.D. “The high fat meal impaired the asthmatic response to albuterol. In subjects who had consumed a high fat meal, the post-albuterol improvement in lung function at three and four hours was suppressed.”

Researchers recruited 40 asthmatic subjects who were randomized to receive either a high-fat, high-calorie “food challenge”, consisting of burgers and hash browns containing about 1,000 calories, 52% of which were from fat; or a low-fat, low-calorie meal consisting of reduced fat yogurt, containing about 200 calories, and 13% fat.

Sputum samples were collected before the meal and four hours afterward, and analyzed for inflammatory markers.

Subjects who had consumed the high-fat meal had a marked increase in airway neutrophils and TLR4 mRNA gene expression. TLR4 is a cell surface receptor that is activated by nutritional fatty acids: TLR4 ‘senses’ the presence of saturated fatty acids, and prompts the cell to respond to the fatty acids as if they were an invading pathogen, releasing inflammatory mediators. Subjects who had consumed the high fat meal also had reduced bronchodilator response.

The mechanism by which a high fat meal could change the bronchodilator response requires further investigation.  However if these results are confirmed by further research, strategies aimed at reducing dietary fat intake may be useful in the overall management of asthma.