Omega Fatty Acids Linked to Air Pollution Burden in Pediatric Asthma
JUNE 19, 2019
Emily Brigham, MD, MHS
Investigators from Johns Hopkins University have shared new data from an observational study indicating that fatty acids have correlation—if not a more direct role—in cases of indoor air pollution-driven asthma symptoms. Led by Emily Brigham, MD, MHS, assistant professor of Medicine at the university’s Division of Pulmonary and Critical Care, the team has found associations notably impactful for the Baltimore area and similar cities.
“There is a lot of pediatric asthma in Baltimore city—more than twice the national average,” Brigham told MD Magazine®. “Children are also exposed to a lot more indoor air pollution than what’s average. And those levels of particulate matter are linked to worsened asthma symptoms.”
Currently, about 20% of the Baltimore City pediatric population is affected by asthma, according to the city’s Health Department—a 112.7% increase from the national population average of 9.4%.
Brigham and colleagues analyzed 135 children with asthma enrolled in the AsthmaDIET Study for baseline, three-month, and six-month counts of weeklong average home indoor concentration of PM 2.5 μm and ≤ 10 μm in aerodynamic diameter. They also assessed for patient intake of omega-3 and omega-6 fatty acids, daily symptoms, and peripheral blood leukocytes.
Patients’ asthma severity and lung function were analyzed at baseline, and adjusted, multivariable regression models were used to determine associations between each fatty acid and outcomes of interest.
At trial’s end, investigators found that greater omega-6 intake was associated with greater odds of asthma severity (P= .02) and worsened lung function, as per forced expiratory volume over 1 second/ forced vital capacity (FEV1/FVC) ratio (P= .01). It was also associated with a worsened effect of indoor PM on patient symptoms, as well as circulating neutrophil rates (P< .01).
Adversely, greater omega-3 intake was associated with reduced burden of indoor PM ≤ 2.5 μm in aerodynamic diameter on patient’s asthma symptoms (P < .01). Though the results couldn’t be conclusive to their exact role in pediatric asthma severity, omega-3 and omega-6 levels in differing patients are a crucial assessment because of the significance of diet in patients with asthma.
“We wanted to take a look and see if other things in the environment could be looked at, and we focused on diet because it’s a huge exposure, something we put into our bodies every day,” Brigham said. “The old adage ‘You are what you eat’ really applies here.”
Brigham theorized it may be the biological action of the molecules constituting the fatty acids that may be either limiting or exacerbating inflammation associated with asthma—which would therefore explain their role in the effect of factors such as air pollution—but future trials would have to more directly seek out causation.
The investigative team is currently conducting an air filter-based intervention trial for pediatric asthma in Baltimore, led by Meredith McCormack, MD, MHS. Brigham also expressed hope for a future dietary intervention trial.
“There need to be further studies before we change practice, reducing or adding omega-3 or -6 in a diet to see if it affects asthma,” Brigham said.
The study, “Omega-3 and Omega-6 Intake Modifies Asthma Severity and Response to Indoor Air Pollution in Children,” was published online in the American Journal of Respiratory and Critical Care Medicine.