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Tokyo, February 7, 2026 – Later in life pregnancies might offer a surprising benefit: reduced allergy risk for children. A large, nationwide study in Japan found that kids born to mothers age 40 or older were significantly less likely to develop food allergies compared to those with mothers aged 25-29.
Could Mom’s Age Be a Shield Against Childhood Allergies?
new research suggests a link between maternal age and a lower incidence of allergic diseases in early childhood.
- Children born to mothers 35-39 years old had a 21% lower chance of food allergy.
- For mothers 40 years and older, the risk reduction was even greater, at 41%.
- Children with parents *both* aged 35 or older had a 11% lower risk of wheezing at age four.
- Similar inverse relationships were observed for wheezing and eczema.
- Researchers speculate that behavioral, environmental, or biological factors linked to older parenthood may play a role.
Is there a connection between when a woman has children and their likelihood of developing allergies? Yes, according to a new study, advanced maternal age appears to be associated with a decreased risk of allergic diseases in young children.
The research, conducted by analyzing data from the Japan Environment and Children’s Study, involved 34,942 singleton mother-child pairs enrolled between January 2011 and March 2014 across 15 regional centers. Researchers followed the children’s health, assessing allergic outcomes at ages one, two, and four.Parents reported physician-diagnosed allergies, and a subset of children underwent testing for house dust mite sensitization.
The average maternal age at the start of the study was 31.0 years, and slightly more then half of the mothers had a personal history of allergic disease. At age one, 6.6% of children had a food allergy. But as maternal age increased, the prevalence of food allergy decreased. Compared to children whose mothers were 25-29 years old, those born to mothers 35-39 years old had a 21% lower chance of food allergy (odds ratio: 0.79; 95% CI: 0.70-0.90). The effect was even stronger for mothers 40 years and older, with a 41% reduction in risk (odds ratio: 0.59; 95% CI: 0.44-0.79).
Similar inverse relationships were observed for wheezing and eczema, persisting through age four. Researchers also assessed house dust mite sensitization in 1,991 children at age two and 1,840 at age four. Children of older mothers showed lower odds of sensitization, even with mothers aged 30-34 (odds ratio: 0.76; 95% CI: 0.59-0.98) and 35-39 (odds ratio: 0.68; 95% CI: 0.50-0.91).
While the study doesn’t prove cause and effect, the findings suggest that advanced maternal age may offer some protection against the advancement of allergies in early childhood. The authors speculate that behavioral, environmental, or biological factors associated with older parenthood could be at play. Further research is needed to understand the underlying mechanisms.
Reference
Yamamoto-Hanada K et al. Parental age and childhood allergy risk.JAMA Netw Open. 2026;9;(1):e2554694.