A New Landmark Study Shows That Early Peanut Introduction Lessens Allergy Risk

Peanut allergy is a severe, potentially life-threatening condition that develops early life and is rarely outgrown. It imposes a significant psychological, as well as economic burden on the family. Its prevalence has quadrupled in the past 13 years. An exciting new study entitled Learning Early About Peanut (LEAP), recently appeared in the New England Journal of Medicine. This study from the United Kingdom shows that early consumption of peanut may dramatically reduce the risk of developing peanut allergy.

In this study, 640 infants, 4-11 months of age and at high risk of peanut allergy (because they had severe eczema, and/or egg allergy), were randomly assigned to consume or avoid peanuts until 5 years of age when their peanut allergy status was determined based on a peanut challenge in a medical environment. The infants had previously passed a peanut challenge in a medical environment with no reaction at the beginning of the study. One group of infants had a negative skin test to peanut, and the other had a borderline test with a wheal (bump) 1-4 mm in diameter. The main finding of the study was that the incidence of peanut allergy was dramatically reduced in the peanut consumption group compared to those who had avoided peanut. In the infants with the negative initial skin test results, the prevalence of peanut allergy at 5 years of age was 13.7% in the avoidance group, and 1.9% in the consumption group. In the group with a borderline allergy skin test reaction, the prevalence of peanut allergy to 5 years of age was 35.3% in the avoidance group, and 10.6% in the consumption group.

The main message of this study was that early introduction of peanut protein may prevent peanut allergy. This represents a dramatic shift in thinking from the past. In 2000, there was a recommendation from the American Academy of Pediatrics to wait until 3 years of age to give peanut products, with the thought that the avoidance might prevent peanut allergy. In 2009, this recommendation was retracted. At this time, there is no official recommendation about when to introduce peanut. However, based on the initial recommendations from the year 2000, later introduction of peanut has become a common practice.

In summary, this is a landmark study that will dramatically change clinical practice, and hopefully help reduce the epidemic of peanut allergy. According to the authors of an accompanying editorial in the same issue of the New England Journal of Medicine, “… the results of this trial are so compelling, and the problem of increasing prevalence of peanut allergy so alarming, new guidelines should be forthcoming very soon.” If you have any questions about how to proceed in light of this new study, please contact one of the providers.


  1. Du Toit, D. et. al. Randomized trial of peanut consumption in infants at risk for peanut allergy. The New England Journal of Medicine. Downloaded from nejm.org on February 24, 2015.
  2. Gruchalla, R. et. al. Preventing peanut allergy through early consumption-Ready for prime time? Downloaded from nejm.org on February 24, 2015.