By Markita Lewis
February 2025 marked the 10-year anniversary of the landmark Learning Early About Peanut Allergy (LEAP) trial, published in The New England Journal of Medicine.¹ Thanks to this study, the allergy world discovered that early introduction of food allergens, rather than delaying them, helps prevent allergies.
A decade ago, little progress had been made in solving peanut allergies. The National Peanut Board supported Dr. Gideon Lack and his team at King’s College for the Israel-UK observational study that led to LEAP. The study observed peanut allergy rates in Jewish schoolchildren in the U.K. and Israel and found that Israeli children, who were introduced to peanuts earlier and more often, had lower allergy rates.²
This prompted the American Academy of Pediatrics (AAP) to partially reverse its 2000 recommendation to delay peanut introduction until age 3. However, many practitioners still advised caution.³
The LEAP trial followed 640 infants between 4 and 11 months old, with severe eczema, an egg allergy, or both. They were assigned to either consume or avoid peanuts until age 5. Only 10.6% of the peanut consumers developed a peanut allergy, compared to 35.3% of those who avoided peanuts.¹
The study changed how health practitioners discuss allergy prevention. The AAP updated its guidelines in 2019 to support early introduction.⁴ Federal guidance in the 2020 Dietary Guidelines for Americans and the 2017 NIAID Addendum Guidelines also recommend early peanut introduction.⁵⁻⁶
Next came the LEAP-On study, which examined if children who consumed peanuts for over four years remained protected after avoiding peanuts for a year. Of 274 original consumers, only 4.8% developed an allergy, compared to 18.6% of 282 avoiders. This showed lasting protection, even without continuous consumption.⁷
Today, the original cohort and their younger siblings are in the final stages of the LEAP Trio study. Recent data shows protection from early introduction can last into adolescence.⁸ For younger siblings, household exposure may slightly increase sensitization, but early peanut introduction still reduces allergy risk.⁹
The LEAP study also influenced the baby food market, leading to products like peanut puffs that support early allergen introduction.
More parents are now introducing peanuts to their children. A 2021 national survey of 3,062 U.S. parents found that 59% offered peanut-containing foods in the first year—17% before seven months, 42% between seven and 12 months.¹⁰
A future without peanut allergies is possible. With continued education and support for health professionals, millions of children can enjoy peanuts for life.
References
[1] The New England Journal of Medicine.Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy
[2] The Journal of Allergy and Clinical Immunology.Early Consumption of Peanuts in Infancy Is Associated With a Low Prevalence of Peanut Allergy
[3] Pediatrics.Effects of Early Nutritional Interventions on the Development of Atopic Disease in Infants and Children
[4] Pediatrics.The Effects of Early Nutritional Interventions on the Development of Atopic Disease in Infants and Children
[5] National Institute of Allergy and Infectious Diseases.Addendum for Peanut Allergy Prevention Guidelines
[6] Dietary Guidelines for Americans 2020-2025.U.S. Department of Agriculture
[7] The New England Journal of Medicine.Effect of Avoidance on Peanut Allergy After Early Peanut Consumption
[8] NEJM Evidence.Follow-up to Adolescence After Early Peanut Introduction for Allergy Prevention
[9] The Journal of Allergy and Clinical Immunology.An Unintentional Randomized Trial of Early Environmental Exposure to Peanut
[10] Pediatrics.Early Peanut Introduction Awareness, Beliefs, and Practices Among Parents and Caregivers