People with asthma are familiar with typical triggers such as exercise, allergies and smoking that can bring on inflammation. Add to that list high-fat meals, which may also increase inflammation in airways, according to a new study.
Australian researchers did tests on 40 people with asthma who were randomly assigned to eat different meals. One was a high-fat meal of fast food hamburgers and hash browns that came in at 1,000 calories, with 52% of calories from fat. The other was a 200-calorie low-fat meal of reduced fat yogurt with 13% of calories from fat. Included in the high-fat test group were 16 obese people; the rest of the study participants were not obese.
Before and after the meals, sputum samples were taken from the test subjects to be analyzed for inflammatory markers. Those who ate the high-fat meals showed a significant boost in airway neutrophils compared with those who ate the low-fat meal. Neutrophils are a common type of white blood cell found in the body's airways while an asthma attack is happening, as well as afterward. Those who ate the high-fat meal also showed an increase, compared with the low-fat group, in a gene expression that is another marker for inflammation.
Eating the high fat meal also prompted a suppressed response to albuterol, a bronchodilator that increases air to the lungs. The obese and nonobese participants in the high-fat group did not differ in their responses.
"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," said Lisa Wood, a research fellow at the University of Newcastle in Australia, in a news release. Wood, lead author of the study, added, "We are designing more studies to investigate this effect. We are also investigating whether drugs that modify fat metabolism could suppress the negative effects of a high fat meal in the airways. 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."
The study was presented at the American Thoracic Society's international conference in New Orleans this week.
Photo: High-fat meals may trigger airway inflammation responses in those who have asthma. Credit: Anacleto Rapping / Los Angeles Times