A major new meta-analysis has examined risk factors associated with developing food allergy in childhood, drawing on evidence from 190 studies covering 2.8 million people. The analysis confirms that fewer than 5 in 100 babies are expected to develop a food allergy.
Researchers identified 342 potential risk factors and assessed the strength of evidence for each. Importantly, the findings reinforce that food allergy does not have a single cause, but arises from a combination of genetic, environmental and early‑life factors.
Risk factors with the strongest evidence of association include early‑life eczema, seasonal allergies or wheezing; delayed introduction of peanut; and having a parent or sibling with food allergy. Vaccination was not found to be associated with increased food allergy risk.
Other factors associated with increased odds, but with lower certainty, include:
- Eczema that develops later in childhood or is more severe
- Dry skin or impaired skin barrier function
- Delayed introduction of foods other than peanut
- Antibiotic exposure during pregnancy or the first year of life
- Dad or both parents having food allergy
- Migration: Parents moving to another country before the child is born, or child raised in different country than where they were born
- Caesarean birth
- Black race.
The study highlights that while some risk factors are modifiable, such as timely introduction of allergenic foods, many are not. Overall, the findings aim to reassure families that even in the presence of risk factors, most children will not develop food allergy, and preventive efforts should focus on evidence-based actions.
Reference: Islam N, et al. Risk Factors for the Development of Food Allergy in Infants and Children: A Systematic Review and Meta-Analysis. JAMA Pediatrics, 2026. DOI:10.1001/jamapediatrics.2025.6105
