Researchers at the Children’s Hospital of Philadelphia (CHOP) have discovered that specific fats commonly found in processed and high-fat foods may trigger a difficult-to-treat form of asthma in children. The findings, published today in Science Translational Medicine, suggest that both dietary changes and existing medications could play a role in managing this type of asthma.
The research was driven by the observed link between childhood obesity and neutrophilic asthma, a severe non-allergic asthma subtype triggered by microbial and bacterial proteins. Unlike allergic asthma, neutrophilic asthma is more resistant to standard treatments and more likely to require hospitalization. Until now, its biological underpinnings were poorly understood.
Focusing on lung macrophages—immune cells that regulate inflammation—scientists examined how dietary fats influence their activity. In preclinical studies, a high-fat diet led to a buildup of stearic acid, a saturated fat found in animal products and processed foods, in lung macrophages.
This accumulation intensified airway inflammation, even without causing obesity. In contrast, oleic acid, a monounsaturated fat present in olive oil and some plant-based foods, appeared to suppress inflammation.
Further experiments showed that blocking the inflammatory molecule IL-1β or inhibiting the protein IRE1⍺ reduced stearic acid–induced inflammation. Elevated levels of both markers are commonly seen in neutrophilic asthma. Importantly, the team validated several of these findings in a cohort of obese children with asthma.
“Asthma is one of the most common chronic illnesses in children, but its treatment is not one-size-fits-all,” said study co-author Dr. Lisa Young, Chief of Pulmonary and Sleep Medicine at CHOP.
“This study highlights how specific dietary components can worsen a particularly challenging asthma subtype. These results open new doors for treatment and suggest that dietary adjustments may help protect at-risk children.”
The research was funded by grants from the National Institutes of Health, the American College of Allergy, Asthma, and Immunology, the CHOP Research Institute, and the University of Pennsylvania.
