Which children are most at risk for food allergy? New meta-analysis offers answers

A systematic review and meta-analysis published in JAMA Pediatrics evaluated the incidence and early-life risk factors associated with the development of food allergy in children.¹ Drawing on 190 studies representing 2.8 million participants across 40 countries, investigators report that approximately 4.7% of children develop immunoglobulin E–mediated food allergy by age 6 years, based on studies confirming diagnosis through oral food challenge testing.

The analysis, led by investigators at McMaster University, synthesized data from cohort, case-control, and cross-sectional studies published through January 1, 2025. Among 176 studies assessing risk factors, 342 potential predictors were examined using multivariable-adjusted analyses.²

Food allergy incidence by age 6

Among studies using food challenge confirmation, the pooled incidence of food allergy was 4.7%. Regional variation was observed, with higher incidence reported in Australia and the United States and lower incidence in parts of Africa and the Middle East.

The authors categorized risk factors by magnitude of association and certainty of evidence, distinguishing between major and minor contributors to risk.

Atopic dermatitis and early allergic disease are strongest predictors

Prior allergic conditions were among the most strongly associated risk factors. Atopic dermatitis within the first year of life was associated with nearly fourfold higher odds of developing food allergy (odds ratio [OR], 3.88; risk difference [RD], 12.0%). Allergic rhinitis (OR, 3.39; RD, 10.1%) and wheezing (OR, 2.11; RD, 5.0%) were also associated with increased risk.

Markers of skin barrier dysfunction were similarly associated. Increased skin transepidermal water loss (OR, 3.36; RD, 10.0%) and filaggrin gene loss-of-function variants (OR, 1.93; RD, 4.2%) were linked to higher odds of food allergy development.

In the accompanying press release, senior author Derek Chu, MD, PhD, 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.”

Delayed allergen introduction increases risk

Delayed introduction of allergenic foods was associated with higher odds of developing food allergy. Introduction of peanut after 12 months of age was linked to more than double the odds of food allergy (OR, 2.55; RD, 6.8%). Similar associations were observed for the delayed introduction of fish and egg.

Subgroup analyses comparing studies conducted before and after the 2015 shift toward early allergen introduction found no credible differences in the strength of associations across risk factors. Although the incidence may have been lower after guideline changes encouraging early introduction, the certainty of that finding was low.

Early-life antibiotic exposure and family history contribute to risk

Antibiotic exposure in infancy was associated with increased risk, particularly when administered within the first month of life (OR, 4.11; RD, 12.8%). Antibiotic use during the first year of life (OR, 1.39; RD, 1.8%) and during pregnancy (OR, 1.32; RD, 1.5%) showed smaller but measurable associations.

Family history was also associated with increased odds. A history of food allergy in either parent or a sibling increased risk, with the highest odds observed when both parents had food allergy (OR, 2.07; RD, 4.8%) and among siblings (OR, 2.36; RD, 6.0%).

Male sex (OR, 1.24; RD, 1.1%), firstborn status (OR, 1.13; RD, 0.6%), and cesarean delivery (OR, 1.16; RD, 1.0%) were associated with smaller increases in risk. Self-identification as Black, as reported in individual studies, was also associated with increased odds compared with White children.

Factors not associated with increased food allergy risk

Several early-life exposures were not associated with meaningful differences in food allergy risk. These included low birth weight, postterm birth, partial breastfeeding, maternal diet during pregnancy, and maternal stress during pregnancy.

Implications for food allergy prevention and guidelines

The investigators classified major risk factors as those with larger effect sizes and risk differences, including early allergic disease, delayed allergen introduction, early-life antibiotic exposure, parental migration, and family history of allergy. Minor risk factors included filaggrin variants, male sex, cesarean delivery, and firstborn status.

Chu stated, “This study has broadened our understanding of food allergies. Future studies should measure and adjust for the same key factors, include more diverse populations, and use food challenge testing more often. New randomized clinical trials and updated guidelines are urgently needed to move our findings into action.” He further emphasized the need for “Designed studies that measure and adjust for the same key factors, include more diverse populations, and use food-challenge testing more often.”

The authors conclude that food allergy development reflects a multifactorial process involving genetic susceptibility, skin barrier integrity, microbial exposures, allergen timing, and social factors. For clinicians, the findings provide quantitative estimates that may help identify infants at highest risk and inform prevention strategies and future guideline updates.

References

1. Islam N, Chu AWL, Sheriff F, et al. Risk Factors for the Development of Food Allergy in Infants and Children: A Systematic Review and Meta-Analysis. JAMA Pediatr. Published online February 09, 2026. doi:10.1001/jamapediatrics.2025.6105
2. McMaster University. What Drives Food Allergies? New Study Pinpoints Early-Life Factors That Raise Risk. McMaster University. February 9, 2026. Accessed February 9, 2026. https://www.newswise.com/articles/what-drives-food-allergies-new-study-pinpoints-early-life-factors-that-raise-risk/?sc=dwhr&xy=10069075