High-fat meals 'a no-no for asthma patients'

A new study has revealed that people with asthma who consume a high-fat, high-calorie meal can show an increased airway inflammation just hours after the binge, and the food can inhibit the response to the medication for the condition. Lead scientist Lisa Wood of Newcastle University said: "This is the first study to show that a high fat meal increases airway inflammation, so this is a very important finding."

The scientists have based their findings on an analysis of 40 asthma patients who were randomised to receive either a high-fat, high-calorie food, consisting of fast food burgers and hash browns containing about 1,000 calories, or a low-fat, low-calorie diet.  They found that the subjects who had consumed the high-fat meal had a marked increase in airway neutrophils and TLR4 mRNA gene expression, the 'Health and Medicine' journal reported in its latest edition.

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.

While the study didn't definitively distinguish between high fat and high energy the increase in TLR4 activity suggests that dietary fat is important to the effects, say the scientists. Subjects who had consumed the high fat meal also had reduced bronchodilator response as compared to those who had consumed the low-fat meal.

Dr Wood said: "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. "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.

"The observation that a high fat meal changes the asthmatic response to albuterol was unexpected as we hadn't considered the possibility that this would occur. If these results can be confirmed by further research, this suggests that strategies aimed at reducing dietary fat intake may be useful in managing asthma."