A burger and fries are not only bad for the waistline, they might also exacerbate asthma, a new study suggests.
Patients with asthma who ate a high-fat meal had increased inflammation in their airways soon afterward, and did not respond as well to treatment as those who ate a low-fat meal, the researchers found.
The results provide more evidence that environmental factors, such as diet, can influence the development of asthma, which has increased dramatically in recent years in westernized countries where high-fat diets are common. In 2007, about 34.1 million Americans had asthma, according to the American Academy of Allergy, Asthma and Immunology. From 1980 through 1994, the prevalence of asthma increased 75 percent. While the results are preliminary, they suggest cutting down on fat might be one way to help control asthma.
"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," study researcher Lisa Wood, of the University of Newcastle, told LiveScience in an e-mail.
The results will be presented at this year's American Thoracic Society's International Conference.
Asthma is a condition in which inflammation in the airways can lead to breathlessness, wheezing and coughing. Symptoms can be triggered by a variety of irritants, including air pollution, smoke and allergens, such as pollen and animal dander.
Previous studies have shown eating fatty foods can trigger the immune system, leading to an increase in cells in the blood that are responsible for inflammation. But no one had specifically looked at the effect of a fatty diet on asthma.
Wood and her colleagues had 40 asthmatic patients eat either a high-fat meal, consisting of burgers and hash browns, or a low-fat meal of yogurt. The high-fat meal was 1,000 calories (52 percent of calories from fat), and the low-fat meal was 200 calories (13 percent from fat).
Analysis of sputum samples revealed that those who had eaten the burger meal had an increased number of immune cells called neutrophils in their airways. Neutrophils play a role in triggering inflammation.
The high-fat diet patients also showed less improvement in their lung function in response to the asthma medication Ventolin (generically known as albuterol) three to four hours after the meal.
The researchers aren't sure why the drug didn't work as well after the high-fat meal and plan further studies to tease out an answer. It could be the fatty acids interfere with the drug in some way, the researchers say.