Babies Exposed to Peanuts Are Less Likely to Be Allergic at Age 12

3 min read

May 29, 2024 – Picky eating among children can come out of nowhere. Parents know that a child’s favorite food one day can be added without warning to the list of refused foods that are spit out, flung, or met with the announcement of “I’m not hungry.”

For parents who have diligently exposed their children to peanuts in hopes of preventing peanut allergy, picky eating has threatened to upset that prevention strategy. 

But new research shows that all is not lost if a child was exposed to peanuts as a baby, toddler, and preschooler, but then later on had a change in diet. Those who regularly ate peanuts up to age 5 were 71% less likely to have a peanut allergy by age 12, compared to kids who entirely avoided peanuts prior to age 5, according to new findings published this week in the journal NEJM Evidence.

An estimated 2 in every 100 children in the U.S. have a peanut allergy, which can sometimes lead to life-threatening symptoms. 

The new report “should reinforce parents’ and caregivers’ confidence that feeding their young children peanut products beginning in infancy according to established guidelines can provide lasting protection from peanut allergy,” Jeanne Marrazzo, MD, MPH, director of the National Institute of Allergy and Infectious Diseases, said in a statement. “If widely implemented, this safe, simple strategy could prevent tens of thousands of cases of peanut allergy among the 3.6 million children born in the United States each year.”

The study is a follow-up to an earlier investigation known as the Learning Early About Peanut Allergy (LEAP) trial and included about 500 children from that original investigation who were randomly assigned between the ages of 4 and 11 months to either be regularly exposed to peanuts in their diet or to entirely avoid them until they were 5 years old. The original study linked early exposure to peanuts with an 81% reduced risk of having a peanut allergy by age 5.

For this follow-up study, children were asked to eat the equivalent of more than 20 peanuts in a controlled setting that gradually increased their intake to monitor for allergic reactions. The average age of adolescents at the time was 13 years old. The researchers found that:

  • Among those who didn’t eat peanuts prior to age 5, 15% had a peanut allergy.
  • Among those who regularly ate peanuts up to age 5, 4% had a peanut allergy.

These latest study results are “conclusive evidence that introducing peanuts into babies’ diets early will achieve long-term prevention of peanut allergy,” according to a summary from King’s College London, where the lead researchers on the team work.

National guidelines on exposing children to peanuts have changed over the years, moving away from the once-held belief that children should not be fed peanuts in their early years. Now, exposure is recommended as young as 4 months old, which is when some babies begin transitioning to solid foods. The current guidelines from the American Academy of Pediatrics vary, based on an infant’s known allergies or eczema symptoms.