Early peanut consumption protects against allergies into adolescence, new research suggests

29 May 2024 --- Amid rising peanut allergy rates in Western countries, a study finds that regularly feeding peanuts to infants up to five years old reduced the rate of allergy in adolescence by 71%. The new research on longer-term allergy prevention builds on the Learning Early About Peanut Allergy (LEAP) clinical trial.

“Decades of advice to avoid peanuts has made parents fearful of introducing peanuts at an early age. The evidence is clear that early introduction of peanuts in infancy induces long-term tolerance and protects children from allergies well into adolescence,” says lead researcher Gideon Lack, professor at King’s College London, UK. 

“This simple intervention will make a remarkable difference to future generations and see peanut allergies plummet.”

According to Lack, early peanut consumption “will prevent more than 100,000 new cases of peanut allergy every year worldwide.” 

LEAP trials 
The study, published in NEJM Evidence, uses findings from the LEAP-Trio study, which builds on the LEAP clinical trial and LEAP-On study, which are all sponsored and co-funded by the National Institutes of Health’s National Institute of Allergy and Infectious Diseases (NIAID). 

The first LEAP clinical trial found that the early introduction of peanuts reduced the risk of developing a peanut allergy at age five by 81%. In this trial, half of the participants were asked to consume peanuts regularly from infancy until age five, while the other half were asked to avoid them during that period. 

In a follow-up study, LEAP-On, children from this first trial were asked to avoid eating peanut products altogether from ages five to six. Most children from the original peanut-consumption group remained protected from the allergy at age six.

The researchers estimate that early peanut consumption could prevent 100,000 new cases of allergies every year.The researchers then followed up on both groups  aged six to 12, or older for the LEAP-Trio study. During that period, participants could choose to eat peanut products in whatever amount or frequency they desired. Children with an allergy were advised to continue avoiding peanuts. In this study, researchers tested whether allergy protection from early peanut consumption would last into adolescence. 

Peanut allergy tests 
The LEAP-Trio study enrolled almost 80% of the original LEAP trial participants, 508 kids, who were an average of 13 years old at baseline. Around half of the participants had been in the LEAP peanut consumption group, and the remainder were in the peanut avoidance group. 

The researchers tested adolescents’ peanut allergy through an oral food challenge. In a controlled setting, they gradually gave participants higher amounts of peanuts to determine if they could safely consume at least 5 g — more than 20 peanuts. 

In addition, participants filled out surveys on their recent peanut consumption patterns, which the researchers verified by measuring peanut dust from participants’ beds — a technique that LEAP researchers previously validated. 

In the early childhood peanut-avoidance group, 15.4% of participants had an allergy, compared to 4.4% from the peanut-consumption group. This translates into a risk reduction of 71% for the consumption group in adolescence. 

Professor George Du Toit, co-lead investigator from King’s College London, comments: “This is a safe and highly effective intervention that can be implemented as early as four months of age. The infant needs to be developmentally ready to start weaning, and peanuts should be introduced as a soft pureed paste or as peanut puffs.”

Half of the LEAP trial participants were asked to regularly consume peanuts up to five years old.Long-term protection  
Studies estimate peanut allergy prevalence at around 2% in the US and is growing strongly. For some people, even small amounts of peanuts can lead to a life-threatening allergic reaction. The US-based company Voyage Foods responded to this trend by developing nut-free and allergenic-free spreads as alternatives to peanut butter. 

The research team underscores that the protective effect of early peanut consumption lasted into adolescence without the need to eat peanuts consistently throughout childhood. They determined that the amount and frequency of peanut consumption varied widely in both groups and also included periods of not eating any peanut products. 

“These findings 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 a peanut allergy,” highlights Dr. Jeanne Marrazzo, NIAID director.

“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 US each year.”

By Jolanda van Hal