Early life factors crucial for childhood food allergy development

A large-scale global study involving 2.8 million children has pinpointed key early-life factors linked to the development of food allergies. The research, one of the most comprehensive of its kind, suggests that food allergies aren’t caused by a single factor, but rather a complex interplay of genetic predisposition, environmental exposures, the body’s microbiome, and social influences.

Understanding the Scope of the Problem

Researchers conducted a systematic review and meta-analysis of 190 studies on childhood food allergy, utilizing gold-standard food challenge testing to confirm diagnoses. Published in JAMA Pediatrics on February 9, 2026, the study revealed that approximately five percent of children will develop a food allergy by the age of six.

The Interplay of Risk Factors

The study’s senior author, Derek Chu, an assistant professor with McMaster’s Departments of Medicine and Health Research Methods, Evidence, and Impact, explained that genetics alone cannot fully account for the rising rates of food allergies. He stated, “Our study highlights that genetics alone cannot fully explain food allergy trends, pointing to interactions – or a ‘perfect storm’ – between genes, skin health, the microbiome, and environmental exposures.”

Several early-life factors were identified as increasing a child’s risk. Infants experiencing eczema in their first year are three to four times more likely to develop a food allergy. Wheezing or nasal allergies also elevate this risk. A family history of allergies – particularly when both parents have allergies – also increases a child’s likelihood of developing a food allergy.

Timing and Exposure Matter

The timing of introducing allergenic foods appears critical. The research found that babies who don’t try foods like peanut, nuts, or eggs until after 12 months of age are more than twice as likely to become allergic to peanuts. Antibiotic use also emerged as a significant factor, with use in the first month of life carrying the highest risk, though antibiotics taken later in infancy and during pregnancy can also contribute to increased risk.

Conversely, the study identified factors not associated with a higher risk of food allergies, including low birthweight, post-term birth, partial breastfeeding, maternal diet, and stress during pregnancy.

What’s Next?

The findings could lead to more effective prevention strategies focused on identifying infants at highest risk. Future research, according to Chu, may focus on more diverse populations and consistent use of food challenge testing. New randomized clinical trials and updated guidelines could emerge from these findings, translating research into practical action.

Frequently Asked Questions

What percentage of children develop a food allergy by age six?

Approximately five percent of children develop a food allergy by the age of six, according to the study.

Does a family history of allergies increase a child’s risk?

Yes, children with allergic parents or siblings are more likely to develop a food allergy, especially if both parents have allergies.

What impact does early antibiotic use have on food allergy risk?

Antibiotic use in the first month of life can lead to a higher risk of food allergy. Antibiotics taken later in infancy and during pregnancy can also increase risk, but to a lesser degree.

Considering the complex interplay of factors identified in this study, how might parents and healthcare providers work together to proactively address potential food allergy risks in infants?