Evelina London trial study sheds new light on peanut allergy

Tuesday 24 February 2015

LEAP study results

New evidence shows that the majority of infants at high risk of developing peanut allergy are protected from the allergy at five years old if they eat peanut frequently, starting within the first 11 months of life.

The LEAP (Learning Early About Peanut Allergy) study – led by Professor Gideon Lack, Head of the Department of Paediatric Allergy at King’s College London and Head of the Children’s Allergy Service at Guy’s and St Thomas’, is published in the New England Journal of Medicine.

It is the first study to show that consumption is an effective strategy to prevent food allergy, contradicting previous recommendations. 

Peanut allergy affects up to 1 in 50 school age children in the UK and its occurrence has more than doubled in the last 10 years in the UK and North America.

The LEAP study, a randomised controlled trial, enrolled 640 children aged 4-11 months from Evelina London Children’s Hospital, who were considered at high risk of developing peanut allergy due to pre-existing severe eczema and/or egg allergy.

Half of the children were asked to eat peanut-containing foods three or more times each week, and the other half were asked to avoid eating peanut until five years of age.

Less than 1% of the children who consumed peanut as per the study protocol and completed the study developed peanut allergy by five years of age, while 17.3% in the avoidance group developed peanut allergy.

The overall prevalence of allergy in all children asked to consume peanut was 3.2% versus 17.2% in the avoidance group. This represents a greater than 80% reduction in the prevalence of peanut allergy.

In total, 98% of children enrolled on the LEAP study completed the final assessment at age five years and the early introduction of peanut-containing foods was found to be safe and well tolerated – infants were not fed whole peanuts which carry a risk of choking in young children.

The study therefore concludes that early, sustained consumption of peanut is safe and associated with a substantial and significant decrease in the development of peanut allergy in high-risk infants by the age of five. Deliberate avoidance of peanut in the first year of life is consequently brought into question as a strategy to prevent allergy.

Professor Gideon Lack says: “This is an important clinical development and contravenes previous guidelines. Whilst these were withdrawn in 2008 in the UK and US, our study suggests that new guidelines may be needed to reduce the rate of peanut allergy in our children.

“The study also excluded infants showing early strong signs of having already developed peanut allergy - the safety and effectiveness of early peanut consumption in this group remains unknown and requires further study. Parents of infants and young children with eczema and/or egg allergy should consult with an allergist, paediatrician, or their GP prior to feeding them peanut products.” 

The children’s allergy service at Evelina London Children’s Hospital is the largest in Europe.

Last updated: March 2022

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