A Parent’s Guide to the LEAP Study on Peanut Allergy Prevention

What was the purpose of the LEAP study?

"evaluated strategies of peanut consumption and avoidance to determine which strategy is most effective in preventing the development of peanut allergy in infants at high risk for the allergy"

Who was the study’s lead investigator?

Dr. Gideon Lack (King’s College, London)

Who funded the LEAP study?

The study was supported by grants from organizations including:

• The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH)
• FARE (Food Allergy Research and Education)
• The National Peanut Board

No manufacturer of peanut products, including The National Peanut Board, could contribute to the study design, the analysis of data or the preparation of the results, so there was no conflict.

The LEAP study was peer-reviewed by impartial experts before it was published.

Who took part in the LEAP study?

• All infants at high risk for peanut allergy – those with severe eczema, egg allergy or both
• Initially 640 children participated
• Starting between 4-11 months of age

What made them high risk for peanut allergy?

Severe eczema, egg allergy, or both

How was the LEAP study conducted?

Babies were first given a skin-prick test (SPT) to determine if they had an existing peanut allergy.

· Only babies with a negative SPT and babies with a positive SPT but very small wheals (1-4mm), moved forward into the study.

The children were randomly divided into 2 groups, with equal numbers of babies with positive SPT and negative SPT.

· One group consumed peanut regularly until the age of 5

· The other group avoided peanut completely until the age of 5

Were any babies excluded from the study?

Yes. Approximately 9% of infants who were pre-screened in the SPT were excluded from enrolling because they likely already had a peanut allergy. These babies had large wheals (raised red, itchy bumps) when they were exposed to peanut during an initial skin prick test.

How much peanut did the “consume” group eat? How often?

• At least 6 grams of peanut protein per week, divided into 3+ doses per week
• They followed this dosing until they reached the age of 5
• The children were fed age appropriate peanut protein for safety reasons.

Did the study have any safety issues?

• There were no significant differences in serious adverse events or rates of hospitalization between the avoidance group and the consumption group.

How did the researchers check to see if the children developed a peanut allergy?

Doctors assessed the children at three times:

• At 12 months of age
• At 30 months of age
• At 5 years of age

Doctors also had between-visit consultations with parents and additional clinic visits were scheduled.

At 5 years of age, the children were tested to determine if they had a peanut allergy, by means of an oral food challenge.

What did the results how?

• Early, sustained consumption of peanut products was associated with a substantial and significant decrease in the development of peanut allergy in high-risk infants.
• The early introduction of peanuts significantly decreased the frequency of the development of peanut allergy among children at high risk for this allergy.
• Early, consistent peanut introduction reduces peanut allergy risk by over 81%
• Peanut avoidance was associated with a greater frequency of clinical peanut allergy than was peanut consumption.