Young woman using an asthma inhaler while a female healthcare professional in scrubs and a stethoscope observes her in a medical office.

A Higher Omega-3 Index Linked to Better Asthma Control

New studies are shedding light on how omega-3 fatty acids—measured by the Omega-3 Index—influence asthma control, medication use, and long-term outcomes.


What Is Asthma and Why Omega-3s Matter

The National Heart, Lung, and Blood Institute (NHLBI) defines asthma as a chronic condition where airway inflammation and narrowing lead to wheezing, chest tightness, shortness of breath, and coughing. Triggers and severity vary, but effective management typically includes an asthma action plan: monitoring, avoiding triggers, and using medications like inhaled corticosteroids (ICS).

Because omega-3 fatty acids (EPA and DHA) have established anti-inflammatory properties, researchers are exploring their role as an adjunct therapy in asthma care.


The Study: Omega-3 Index and Asthma Control

A recent study in Nutrients compared the Omega-3 Index in adults with and without asthma:

  • Participants: 255 with asthma, 137 without.

  • Assessments: Blood samples (Omega-3 Index) + lung function (Juniper Asthma Control Questionnaire).

Key Findings

  • Overall Omega-3 Index levels were similar in people with and without asthma.

  • Within asthma patients, those with a higher Omega-3 Index (≥8%) had:

    • Better asthma control scores.

    • Lower maintenance ICS doses.

  • A low Omega-3 Index was associated with poorer asthma control.

Conclusion: Achieving an Omega-3 Index of ≥8% may support better asthma management and reduce medication dependence.


Evidence in Children

  • 2018 Study – Journal of Allergy and Clinical Immunology: In Practice

    • Children with higher omega-3 levels were less likely to develop asthma or recurrent wheeze by age 3.

    • The strongest benefit was seen in children with higher vitamin D levels, suggesting a synergistic effect.

  • 2022 Study – American Journal of Respiratory and Critical Care Medicine

    • In 135 Baltimore children, higher dietary omega-3 intake was linked to fewer asthma symptoms triggered by indoor air pollution.

    • Diets high in omega-6s (soy, corn oil) worsened asthma symptoms.

    • Researchers emphasized that improving diet alongside air quality may reduce asthma disparities.


Mixed Evidence: When Omega-3s Don’t Help

Not all trials find benefits:

  • A 2021 study (Annals of the American Thoracic Society) tested 4 g/day fish oil (3.18 g EPA+DHA) in obese adolescents with uncontrolled asthma.

  • After 6 months, no improvements in asthma control, lung function, or exacerbations were observed.

  • Authors noted obesity-related inflammation might blunt the benefits of omega-3s, and higher doses or longer treatment could be required.


Practical Implications

  • For adults with asthma: Aiming for an Omega-3 Index ≥8% could improve control and reduce medication needs.

  • For children: Omega-3s may lower risk of asthma and wheeze, especially when combined with adequate vitamin D.

  • For families in polluted environments: Omega-3-rich diets may help buffer the effects of poor air quality.

  • For clinicians: Omega-3 Index testing offers an evidence-based tool to personalize dietary and supplement guidance.


Key Takeaways

  • Higher Omega-3 Index = better asthma control and reduced ICS use.

  • Benefits extend to children, particularly when omega-3s and vitamin D are both sufficient.

  • Not all groups respond equally—obesity may complicate effectiveness.

  • Dietary shifts toward omega-3-rich foods (salmon, sardines, herring) and away from omega-6-heavy oils may offer protective benefits.