Exclusive Breastfeeding Linked to Lower Asthma and IgE Sensitization Risk Into Young Adulthood
Exclusive breastfeeding for at least 4 months was associated with a reduced risk of asthma and IgE sensitization extending into young adulthood, according to findings from a large Swedish birth cohort.
The study followed 3919 participants with documented breastfeeding data at age 1 year and serial assessments of asthma and IgE sensitization through age 24 years. Asthma status was obtained through repeated questionnaires, and blood samples were collected at ages 4, 8, 16, and 24 years to assess IgE sensitization. Longitudinal analyses were conducted using generalized estimating equations.
Participants who were exclusively breastfed for 4 months or longer had significantly lower odds of asthma through age 24 years (adjusted odds ratio [ORadj], 0.75). The protective association was strongest in childhood, with a statistically significant inverse relationship observed up to age 12, but not beyond. When asthma phenotypes were examined, exclusive breastfeeding was significantly associated with reduced odds of persistent asthma (ORadj, 0.64), while no association was found with late-onset asthma.
Breastfeeding was also inversely associated with IgE sensitization overall (ORadj, 0.82), suggesting broader effects on allergic immune responses. When children with early wheeze or eczema during breastfeeding were excluded, associations with both asthma and sensitization strengthened, indicating that reverse causation was unlikely to explain the findings.
The authors concluded that “exclusive breast-feeding for ≥4 months was inversely associated with asthma, in particular with disease onset during the first 12 years of life,” and also with IgE sensitization into young adulthood.
Reference
Kull I, Ödling M, Andersson N, Melén E, Ekström S, Bergström A. Breast-feeding is inversely associated with asthma and IgE sensitization up to young adulthood. J Allergy Clin Immunol. Published online January 20, 2026. doi:10.1016/j.jaci.2025.12.1011
