A new peanut allergy study made international news recently. The Learning Early About Peanut Allergy (LEAP) study tackled the issue of the best timing for peanut introduction to prevent peanut allergy. Prior to 2008, doctors advised delaying peanut introduction until after age 3, particularly in high-risk children (those with a parent or sibling with allergies).

Reducing risk

In the LEAP study, 640 high-risk infants were randomly selected to either be introduced to peanuts between the ages of 4-11 months, or wait until age 5. In the early introduction group there was a 70-80 percent reduction in the risk of developing peanut allergy, compared to the group that delayed introduction. These groundbreaking findings have received a lot of attention, and offer hope in slowing the rising rate of peanut allergy.

Parental guidance

Despite the excitement, it’s important for parents to understand additional details about the study, and early peanut introduction in high-risk children. Most importantly, parents should know that early introduction doesn’t outright prevent peanut allergy from occurring. Cases of peanut allergy occurred with early introduction, but significantly fewer cases occurred compared to delayed introduction.

"Cases of peanut allergy occurred with early introduction, but significantly fewer cases occurred compared to delayed introduction."

More exciting, infants in the study who had peanut sensitization (e.g., a positive test without known exposure) and who tolerated a supervised “test” peanut feeding, received protective benefit with subsequent exposures. The findings did not apply to older children or to those with existing peanut allergy—only to infants who had never before eaten peanut.


The LEAP study provides firm evidence that early peanut introduction is appropriate for high-risk infants, defined as having severe eczema and/or an existing food allergy such as eggs. These high-risk infants may benefit from consultation with a board-certified allergist to determine if peanut allergy testing and/or supervised introduction is appropriate.

While more formal recommendations are being developed, both the study authors and sponsor (NIAID) recommend that the findings can be immediately applied, so as not to deny tens of thousands of infants potential benefit.

If you suspect a peanut allergy, find a board-certified allergist in your area for proper diagnosis and management.