Summary
Asthma is an inflammatory disease affecting the airways, causing wheezing, coughing and difficulty in breathing. In the light of the anti-inflammatory properties of certain Omega-3 fatty acids, it is perhaps unsurprising that research indicates EPA and DHA play a positive role in asthma, for both adults and children.
 
Introduction
Asthma is a chronic condition that affects the parts of the system that we use to breathe, also called the respiratory system. Worldwide, up to 334 million people are affected by this condition, with the incidence increasing drastically over the past decades. In asthma, persistent oversensitive inflammation reactions cause the airways to constrict, with difficulty in breathing as a result. The main part of the airways affected by asthma are bronchial tubes, which are the major pathways through which fresh air enters our lungs. These are very susceptible to inflammation in asthma; certain triggers such as pollen, smoke or intense exercise can cause the immune system to overreact and create excessive swelling and inflammation of the bronchial tubes. In turn, the bronchial tubes then produce an overload of mucus and the muscles surrounding these tubes constrict, also referred to as bronchoconstriction. This excess of mucus and narrowing of bronchial tubes means that less fresh air can enter the lungs. In turn, this leads to the classical asthma symptoms of wheezing, coughing, difficulty breathing and tightness of the chest area. Without proper treatment, recurrent episodes of bronchial tube inflammation can lead to permanent changes in the airways, such as increased mucus production and thickening of the bronchial tubes, worsening symptoms as a result. Current management options include prevention of exposure to known environmental asthma triggers. Furthermore, patients often get prescribed corticosteroid inhalers to reduce inflammation and bronchodilators (e.g. via asthma puffers) to counter bronchoconstriction and clear mucus in the lungs.
 
Asthma often presents itself during early phases of life, though it can develop during adulthood as well. Worldwide, up to 10% of the population has at one point in their lives been affected by asthma. A common way to assess asthma severity is with spirometry, which uses the parameters of Forced Expiratory Volume (FEV) and Forced Vital Capacity (FCV) to assess one’s pulmonary function (breathing ability). These include the maximum air one can exhale in a second, the maximum total amount a person can exhale and how much of one’s air capacity someone can exhale in a second. Respiratory function refers to all parts of our breathing system such as the lungs, airways, surrounding muscles and ability to exchange oxygen. In turn, pulmonary function refers specifically to the functional capability of the lungs.
 
As Omega-3 fatty acids are well-known for their anti-inflammatory properties, many studies have been conducted to examine their beneficial effects in the context of asthma, both during pregnancy, early childhood and adulthood, discussed below.
 
Research findings
Omega-3 fatty acids and asthma in early life phases
As asthma typically presents itself early in life, a multitude of studies have been conducted that investigated the relationship between childhood asthma and Omega-3 fatty acids. Both maternal intake during pregnancy and infant’s dietary intake via formula indicate a positive role of Omega-3 fatty acids in the light of asthma, as described in the studies below.
 
Bisgaard an colleagues set up a large randomized clinical trial with 736 pregnant women, investigating the effects of Omega-3 fatty acids on prevalence of asthma during the newborn’s first three years of life (Bisgaard et al. 2016). Participants at 24 weeks of gestation received either a placebo (olive oil) or fish oil containing 888 mg DHA and 1320 mg EPA every day until one week after delivery. A follow-up period of 3 years was completed by a total of 664 mother-children pairs, during which prevalence of wheezing and asthma were monitored in the children. Both dietary intake of Omega-3 fatty acids and blood levels of EPA and DHA were assessed at the beginning and end of the supplementation period. Mothers were instructed to maintain a diary, monitoring any lung-related negative health symptoms of their child. Additionally, 9 clinical visits of the mother and child were conducted throughout the study, during which the child’s respiratory health was examined by monitoring prevalence of asthma and persistent wheeze. It was found that in the follow-up period, risk of asthma or persistent wheeze was 16.9% in the fish oil supplementation group and 23.7% in the placebo group, translating to a relative risk reduction of 30.7%.
 
Researchers of the university of Paris examined the relationship between enrichment of infant formula with DHA and ARA and the incidence of allergies (such as asthma) in the first years of life (Adjibade et al. 2022). In a study with a large cohort of 8389 infants, surveys filled out by parents from ages of 2 months to 5.5 years of their child were used to determine the prevalence of allergies. The authors reported that 36% of the cohort’s infants were fed with DHA and ARA enriched infant formula, 11% with DHA, ARA and EPA enriched formula. It was found that up to ages of 5.5 years, consumption of infant formula enriched polyunsaturated fatty acids (in this case DHA, ARA, EPA) was associated with decreased usage of asthma medications compared to infants who consumed non-enriched formula. This indicates that these polyunsaturated fatty acids likely play a positive role in the face of early childhood asthma prevalence or severity.
 
Dietary intake of Omega-3 fatty acids during childhood may be associated with a decreased risk of asthma that is sustained throughout adulthood, as reported by Ekström and colleagues in their observational study (Ekström et al. 2022). Based on dietary intake data and blood plasma measurements at ages 8 and 16, these authors reported that high intake of Omega-6 fatty acids was associated with increased risk of asthma at the age of 24. In contrast, higher levels of Omega-3 fatty acids in plasma at ages 8 and 16 were associated with a decreased risk of asthma at 24 years of age. This highlights the importance of Omega-3 fatty acids as a crucial nutrient to support health throughout childhood into adulthood.  
 
Asthma and DHA in adults
In a multi-center cross-sectional study, Huether and fellow scientists examined the relationship between dietary intake of Omega-3 fatty acids and the burden of asthma in obese adults with poorly controlled asthma (Huether et al. 2024). A total of 102 adults with an average age of 52 participated in the study. Their dietary intake of Omega-3 fatty acids ALA, EPA and DHA were assessed using a questionnaire, which was used to establish correlations with asthma symptoms and control, as well as lung function. Amongst the participants, the authors found that higher consumption of Omega-3 fatty acids was directly related to an increase in pulmonary function, as measured by the aforementioned Forced Expiratory Volume (FEV) and Forced Vital Capacity (FCV). In short, this means that on average, overweight people with poorly controlled asthma who consumed more Omega-3 fatty acids showed better performance in breathing tests.
 
Conclusion
Asthma can be an extremely debilitating disease, hindering ones ability to breathe and function in their day to day life, even proving to be fatal for many individuals. Though medication such as the commonly known asthma puffers are proven to help, these treatment options are not aimed at curing or preventing asthma itself. They only act to prevent or relieve symptoms, and may not be available to people worldwide. Strikingly, Omega-3 fatty acids have been shown to play a positive role in the context of asthma throughout various stages of life. Consumption of Omega-3 fatty acids during pregnancy and childhood seems to play a protective role against asthma risk and severity. Moreover, these protective effects of Omega-3 fatty acid consumption during childhood are shown to persist into adulthood. Correspondingly, in adults with obesity and poorly controlled asthma, higher consumption of Omega-3 fatty acids is related to better lung function. Taken together, the findings above highlight the positive role Omega-3 fatty acid intake can play in the context of asthma.
 
 
References
 Adams, Shahieda, Andreas L. Lopata, Cornelius M. Smuts, Roslynn Baatjies, and Mohamed F. Jeebhay. 2019. ‘Relationship between Serum Omega-3 Fatty Acid and Asthma Endpoints’. International Journal of Environmental Research and Public Health 16 (1): 43. https://doi.org/10.3390/ijerph16010043.

Adjibade, Moufidath, Camille Davisse-Paturet, Jonathan Y. Bernard, Karine Adel-Patient, Amandine Divaret-Chauveau, Sandrine Lioret, Marie-Aline Charles, and Blandine de Lauzon-Guillain. 2022. ‘Enrichment of Infant Formula with Long-Chain Polyunsaturated Fatty Acids and Risk of Infection and Allergy in the Nationwide ELFE Birth Cohort’. Allergy 77 (5): 1522–33. https://doi.org/10.1111/all.15137.

Bisgaard, Hans, Jakob Stokholm, Bo L. Chawes, Nadja H. Vissing, Elin Bjarnadóttir, Ann-Marie M. Schoos, Helene M. Wolsk, et al. 2016. ‘Fish Oil-Derived Fatty Acids in Pregnancy and Wheeze and Asthma in Offspring’. The New England Journal of Medicine 375 (26): 2530–39. https://doi.org/10.1056/NEJMoa1503734.

Ekström, Sandra, Emmanouela Sdona, Susanna Klevebro, Jenny Hallberg, Antonios Georgelis, Inger Kull, Erik Melén, Ulf Risérus, and Anna Bergström. 2022. ‘Dietary Intake and Plasma Concentrations of PUFAs in Childhood and Adolescence in Relation to Asthma and Lung Function up to Adulthood’. The American Journal of Clinical Nutrition 115 (3): 886–96. https://doi.org/10.1093/ajcn/nqab427.

Huether, K.m., J. Skelly, E. Brigham, M.c. Mccormack, and A.e. Dixon. 2024. ‘Omega-3 Fatty Acid Intake Is Associated With Bronchodilator Response in Patients With Obesity and Poorly Controlled Asthma’. In C35. INNOVATIVE BIOMARKERS TO IDENTIFY ALLERGIC INFLAMMATION, A5406–A5406. American Thoracic Society International Conference Abstracts. American Thoracic Society. https://doi.org/10.1164/ajrccm-conference.2024.209.1_MeetingAbstracts.A5406.