A new study published in the Journal of American Medical Association showed that children born to mothers 35 years of age or older had a 21–41% lower risk of developing food allergies when compared to children born to moms between the ages of 25 and 29.Gene-environment interactions have an impact on allergic disorders in children. The association between advanced parental age and the risk of childhood allergies is still unknown, despite the fact that it has been linked to genetic and epigenetic changes. Thus, this study investigated the relationship between the risk of allergic diseases in early children and the age of the parents at childbirth.
The Japan Environment and Children’s Study (JECS) provided data for this countrywide, multicenter, population-based, prospective birth cohort study. Between January 2011 and March 2014, participants were registered at 15 regional centers in Japan, and follow-up data was gathered at the ages of one, two, and four. Singular live births with information on parental age and allergic outcomes were eligible participants. Parental reports were used to gather physician-diagnosed allergy results. A sensitivity of the subcohort to house dust mites (HDM) was evaluated. Physician-diagnosed food allergies, wheezing, asthma, and eczema at ages 1, 2, and 4 were the main outcomes. HDM sensitization at ages 2 and 4 was the secondary endpoint.51.2% of the 34,942 mother-child pairs had a medical allergy history, and the mean (SD) maternal age was 31.0 (4.7) years. At one year, the prevalence of food allergies was 6.6% (95% CI, 6.4–6.9), and it declined as the mother’s age increased. Children of mothers aged 35–39 years (OR, 0.79; 95% CI, 0.70–0.90) and ≥40 years (OR, 0.59; 95% CI, 0.44–0.79) had reduced odds of food allergies than moms aged 25–29.Wheezing at age 4 was less common in children whose parents were both older than 35 (OR, 0.89; 95% CI, 0.82–0.95). Lower odds of HDM sensitization at 2 and 4 years were similarly linked to older mothers (30–34 years: OR, 0.76; 95% CI, 0.59–0.98; 35–39 years: OR, 0.68; 95% CI, 0.50–0.91). Overall, this study examined the protective effect of older mothers being linked to a lower incidence of food allergies, wheeze, and asthma in children. Source:Yamamoto-Hanada, K., Harama, D., Sato, M., Miyaji, Y., Sakamoto, K., Nishizato, M., Yang, L., Kumasaka, N., Mezawa, H., Iwamoto, S., Pak, K., Nishizawa, T., Nadeau, K. C., Fukami, M., Ohya, Y., & Japan Environment and Children’s Study (JECS) Group. (2026). Parental age and childhood allergy risk. JAMA Network Open, 9(1), e2554694. https://doi.org/10.1001/jamanetworkopen.2025.54694
