Children introduced to peanut products during infancy and regularly fed with them till the age of five are at a reduced risk of developing peanut allergy in their adolescence, a study revealed.

Peanut allergy is one of the most prevalent allergies, affecting about 2% of the U.S. population. Those with a peanut allergy can experience symptoms ranging from mild to severe, potentially life-threatening reactions known as anaphylaxis. The patients typically develop allergy in childhood, which often persists for life, although approximately 20% of individuals may eventually outgrow it.

In the study by the National Institute of Allergy and Infectious Diseases (NIAID), researchers discovered that early introduction of peanut products can reduce the incidence of peanut allergy in adolescence by 71%. This reduction was observed even if children stopped consuming peanut products after the age of five.

"Today's 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 peanut allergy. 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," Dr. Jeanne Marrazzo, NIAID Director, said in a news release.

The findings come from the LEAP-Trio study, which expanded on the earlier Learning Early About Peanut Allergy (LEAP) clinical trial. During the LEAP trial, half of the participants consumed peanut products regularly from infancy until they were 5 years old and were compared with the other half who avoided peanuts entirely during this time. The results indicated that introducing peanut products early on reduced the risk of developing a peanut allergy by 81% by age 5.

In a follow-up trial called Leap On, the same participants were asked to avoid peanut products from ages 5 to 6 years. Most children in the original peanut consumption group still showed protection from peanut allergy at age 6.

In the LEAP-Trio study, which aimed to determine if the protection from early consumption of peanut products persisted into adolescence, researchers enrolled 80% of the original 640 participants from the LEAP trial.

The participants were at an average age of 13. There were 255 participants in the LEAP peanut consumption group and 253 in the LEAP peanut-avoidance group. Their peanut allergy status was assessed using an oral food challenge, where they were given gradually increasing amounts of peanuts in a controlled setting. This test determined if they could safely consume at least 5 grams of peanuts, equivalent to more than 20 peanuts.

Around 15% of participants from the early childhood peanut-avoidance group and 4% from the early childhood peanut-consumption group developed allergy at the age of 12 or older.

"These results showed that regular, early peanut consumption reduced the risk of peanut allergy in adolescence by 71% compared to early peanut avoidance," the news release stated.

The results also showed that the "protective effect of early peanut consumption lasted without the need to eat peanut products consistently throughout childhood and early adolescence."

"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 peanut in infancy induces long term tolerance and protects children from allergy well into adolescence," lead investigator Professor Gideon Lack said.