What Is The LEAP Study?

By Lil Mixins Research Staff

Are you tired of hearing about “The LEAP Study,” but not knowing what it means?


In the world of pediatrics and allergies, the LEAP Study is the biggest thing since sliced bread. 

Learning Early About Peanut (LEAP) 

The LEAP study was conducted in 2015 and discovered a link between feeding babies peanuts early -- a practice called early introduction -- and preventing peanut allergies.

The LEAP study and other following studies prompted the American Academy of Pediatrics to change decades-worth of food allergy advice and instruct parents to start feeding babies peanuts as early as 4 months old. 

A Bit of History About Food Allergies

In 2000, the American Association of Pediatrics (AAP) started telling parents not to introduce allergenic foods until 12 months (dairy), 24 months (eggs) and 36 months (peanuts, tree nuts, fish). 

For a decade, this was the prevailing wisdom told to every new parent. And unfortunately, even though the LEAP study and the American Academy of Pediatrics now recommend otherwise, this advice persists among the general public.

To make things even worse, it’s possible that this advice contributed to an increase in the rate of food allergies among children.

In the mid to late-2000s, scientists began wondering if maybe we had it backwards. One study found that the risk of the peanut allergy was 10 times higher for Jewish children in the United Kingdom as compared to Jewish children in Israel. These children were genetically very similar, but peanuts are everywhere in Israeli cuisine, including the food fed to infants

It led scientists to question if there was something to learn from cultures and societies where the rate of peanut allergies is low. This became the foundation of the LEAP study.

How did The LEAP Study “prove” that early introduction works?

The Learning Early About Peanut Allergy (LEAP) team studied a group of infants identified as high risk for peanut allergy — babies with severe eczema and/or egg allergy. This group of babies had a 30% chance of developing peanut allergy.

Each baby had a skin prick test, where they were exposed to a tiny amount of peanut just under their skin. If a welt, or wheel, developed on the baby’s skin, they were considered “sensitized” to peanuts already. Those who showed no wheel were considered not yet sensitized.

Sensitization to peanuts means somehow, somewhere, a baby has already been exposed to peanuts and created antibodies responding to that specific protein. Sensitization does not confirm an allergy, however.

The parents of half the babies in each group (sensitized or not) were told that their baby should “eat six grams of peanut protein per week” while the other half were told to “avoid peanuts.”

The scientists followed the babies until they were 5 years old to see who developed peanut allergies.

The results for babies who followed the rules were striking:

 LEAP Study Results

Nearly all of the babies who regularly ate peanuts had no allergy by age 5.

Even those who were already sensitized to peanuts when the study started had extremely low allergy rates.

Giving children peanuts regularly decreased their likelihood of getting a peanut allergy by 80%.

The conclusion was clear: regular exposure to peanuts significantly decreased the likelihood that a baby would develop a peanut allergy.

The data from the LEAP Study, and some additional follow-on studies, was so conclusive that the American Academy of Pediatrics completely changed their guidelines in 2016. The AAP now recommends early introduction of peanuts for infants starting at 4-6 months of age. 

It doesn’t matter if your baby is high risk because they have eczema or an egg allergy, or if they are low risk, the message is still the same -- early and consistent exposure to allergens dramatically reduces the risk of an allergy developing.

How exactly do you keep up this rigorous exposure, especially with early eaters? Read our Peanut Allergy Guide for full instructions on how to safely introduce peanuts to your baby’s diet and get the most out of early peanut introduction.

Or jump right in with our Infant Peanut Powder Mixin

Hopefully, the details of the LEAP Study are a bit clearer now. And if you ever want to read the original study, you can find it in our Parent Resource Center, along with a whole bunch of other useful items.