Early Peanut Eating Cut Allergy Rates Years Later in High-Risk Children

CATEGORY: IMMUNE HEALTH

Children who ate peanut regularly from infancy until age 5 were 71% less likely to have a peanut allergy at age 12 than children who had avoided peanut in those early years—4.4% versus 15.4%—even though both groups ate peanut freely, or not at all, after age 5, in the LEAP-Trio follow-up of a randomized trial published in NEJM Evidence.¹ Because infants were randomly assigned to each approach, the result carries more weight than studies that simply observe habits.

Old Advice Said Keep Peanut From Young Children

Peanut allergy is one of the most common food allergies in children, it usually lasts for life, and it can cause anaphylaxis—a severe, whole-body allergic reaction that can be life-threatening. For decades, the standard advice was to keep peanut away from young children at risk. The LEAP research program tested the opposite idea: that a baby’s immune system learns to treat a food as harmless—a state doctors call tolerance—by meeting it early and often.

640 High-Risk Infants Aged 4 to 11 Months

The original LEAP trial enrolled 640 infants aged 4 to 11 months in the United Kingdom who were at high risk of peanut allergy because they had severe eczema (an itchy, inflamed skin condition), egg allergy, or both; all were assessed by clinicians before starting. Half were randomly assigned to eat peanut-containing foods regularly until age 5, half to avoid peanut entirely. At age 5, allergy testing showed 3.2% of the eating group had a peanut allergy versus 17.2% of the avoidance group—an 81% reduction. After age 5 the restrictions ended, and everyone chose freely. LEAP-Trio then re-enrolled 508 of the original children, now 12 years old, and tested them again—in most cases with an oral food challenge, in which a child eats small, increasing amounts of peanut under close medical supervision.¹

Protection Held Through Long Stretches Without Peanut

At age 12, peanut allergy remained far more common in the group that had avoided peanut in infancy: 15.4% versus 4.4% in the early-eating group. In numbers, 38 of 246 children in the avoidance group had peanut allergy, versus 11 of 251 in the early-eating group.¹ Children in both groups reported long stretches after age 5 with little or no peanut, yet the protection held—suggesting durable tolerance rather than an effect that needs constant topping up. Blood tests pointed the same way: the early-eating group showed an antibody pattern associated with tolerance. Side effects in the study were uncommon and mostly related to the supervised food challenges.¹

Whole Peanuts Are a Choking Hazard for Infants

The trial studied high-risk infants who were evaluated and followed by allergy specialists, so the results describe early introduction under medical guidance, not any particular feeding routine at home—and whole peanuts themselves are a choking hazard for infants, which is why the trial used peanut-containing foods. What it does show is a window in infancy when the immune system can learn to accept peanut, with protection lasting at least into adolescence.¹

Three Pooled Trials, 69% Less Peanut Allergy

Other research points the same way. A 2024 review pooling three randomized trials of early peanut introduction—this one among them—found peanut allergy roughly 69% less common in the infants given peanut early.² And in US primary-care records, peanut allergy diagnoses in children under 3 were about 35% lower after national guidelines changed to favor early introduction, though such before-and-after comparisons show association rather than cause.³

Key Takeaways

• In the LEAP-Trio follow-up of a randomized trial, eating peanut regularly from infancy to age 5 was linked to a 71% lower rate of peanut allergy at age 12—4.4% versus 15.4%.¹
• The protection persisted even though children in both groups often went long periods without eating peanut after age 5, suggesting durable immune tolerance.
• The trial enrolled infants at high risk of peanut allergy who were assessed and monitored by clinicians, so the findings reflect early introduction under medical supervision.

References

1. Du Toit G, Huffaker MF, Radulovic S, et al. Follow-up to Adolescence after Early Peanut Introduction for Allergy Prevention. NEJM Evidence. 2024;3(6):EVIDoa2300311. link
2. Tuballa A, Connell D, Smith M, et al. Introduction of allergenic food to infants and allergic and autoimmune conditions: a systematic review and meta-analysis. BMJ Evidence-Based Medicine. 2024;29(2):104–113. link.
3. Gabryszewski SJ, Dudley J, Faerber JA, et al. Guidelines for early food introduction and patterns of food allergy. Pediatrics. 2025;156(5):e2024070516. link.