Omega-3 Shows No Benefit For Obese Pediatric Asthma Control

Jason E. Lang, MD, MPH

Omega-3 fatty acid supplementation—a therapy suggested to benefit cardiovascular, neurologic, inflammatory, and other indications—has no positive effect on asthma control in adolescent and pediatric patients.

In a new study assessing the supplementation in overweight/obese patients with uncontrolled asthma aged 12 to 25 years old, a team of investigators, led by Jason E. Lang, MD, MPH, of the Duke Children’s Hospital and Health Center, Duke University School of Medicine, found they could not recommend omega-3 fatty acid (n3PUFA) as a preventive measure.

“These findings do not support a strategy of therapeutic n3PUFA supplementation in these patients with symptomatic asthma,” they wrote.

Study authors did not respond to a request for comment at the time of publication. In a statement regarding the results, Lang noted that growing evidence pointing to systemic inflammation being caused by an asthmatic patient’s obesity.

“Because the omega-3 fatty acids in fish oil have anti-inflammatory properties, we wanted to test whether fish oil would have therapeutic benefits for these patients,” Lang said.

In a multi-center trial, 98 participants were randomized 3:1 to receive either 4g n3PUFA daily (n= 77) or soy oil control (21) for 24 weeks. Using the Asthma Control Questionnaire (ACQ) to assess asthma control metrics, investigators also monitored patient exacerbations, forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁).

Approximately 86% of participants had completed their physician visits during the trial period. Participants on both fish oil and soy oil reported similar mean change in ACQ score at 6 months (-0.09 vs -0.18, respectively). Additionally, urinary leukotriene-E (uLTE) levels were similar (P= .24), as were predicted FEV₁ percentages (P= .88), and exacerbations (RR= .92; 95% CI: 0.30-2.89), at 24 weeks.

With consideration to the role of a variant in gene ALOX5 in the study’s findings, investigators found no association. Gene mutations are capable of reducing the body’s response to anti-leuoktriene drugs, which work to combat inflammatory molecules behind asthma attacks. Though the ALOX5 variant was linked to patients’ leukotriene production, it did not influence the fish oil treatment’s efficacy.

The lacking disparity of benefits between treatment and control groups were contrarian to at least 1 other recent pediatric asthma observation involving omega-3 fatty acid. A study presented at the 2018 American Academy of Allergy, Asthma & Immunnology (AAAAI) and World Allergy Joint Congress last March reported that 4 g PUFA compared to olive oil control in children aged 24 weeks to 3 years resulted in a two-fold reduction in wheezing or asthma—in patients with exceptionally low PUFA levels or fatty acid desaturase genotype.

Reduced PUFA levels are commonly prevalent in obese patients with asthma, Lang and colleagues observed, as it can indicate a diet low in fresh vegetables and fish. Worsened PUFA levels are also associated with greater asthma risk—just as much as improved levels are associated with lower obesity and asthma risk.

“Populations consuming high amounts of cold-water fish rich in long chain polyunsaturated fatty acids such as the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), traditionally have a low incidence of asthma,” investigators wrote.

Within this specific asthma patient group, however, the fatty acids did not prove therapeutic. Lang suggested that differing doses, or a long treatment regimen, could possibly result in symptom improvements.

The study, "Fish Oil supplementation in Overweight/Obese Patients with Uncontrolled Asthma: a Randomized Trial," was published online in the Annals of the American Thoracic Society.