Early exposure to peanuts significantly reduces the likelihood of peanut allergies later in life

Introducing peanut products to children from infancy to age five significantly reduces the likelihood of peanut allergies later in life. This was demonstrated by a new study, showing a remarkable 71% reduction in peanut allergy rates among adolescents who were fed peanut products early on, regardless of their subsequent peanut consumption habits.

Sponsored and co-funded by the National Institutes of Health’s National Institute of Allergy and Infectious Diseases (NIAID), these findings offer solid evidence that early exposure to allergens can lead to long-term allergy prevention. The results were published in the journal NEJM Evidence.

“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,” said NIAID Director Jeanne Marrazzo, M.D., M.P.H. “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.”

This groundbreaking research is part of the LEAP-Trio study, which follows the pivotal Learning Early About Peanut Allergy (LEAP) clinical trial and its follow-up, the LEAP-On study. Both were also sponsored and co-funded by NIAID.

The original LEAP trial divided participants into two groups: one group regularly consumed peanut products from infancy until age five, while the other group avoided peanuts entirely during this period.

At age five, children in the peanut-consuming group had an 81% lower risk of developing a peanut allergy compared to those who avoided peanuts. In the follow-up LEAP-On study, children from the peanut-consuming group continued to be protected from peanut allergy even after avoiding peanuts from ages five to six.

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To explore the long-term effects of early peanut consumption, the LEAP-Trio study tested whether the protection against peanut allergy would persist into adolescence. The researchers allowed children to eat peanuts as desired after age six, except for those who had developed a peanut allergy by that age, who were advised to continue avoiding peanuts.

The study enrolled 508 participants from the original LEAP trial, representing nearly 80% of the initial group. These children, now averaging 13 years old, included 255 from the peanut-consuming group and 253 from the peanut-avoidance group.

The primary method for assessing peanut allergy in the LEAP-Trio study was an oral food challenge. Participants were given gradually increasing amounts of peanut in a controlled environment to determine if they could safely consume at least five grams of peanut, equivalent to more than 20 peanuts. The study also collected data on participants' recent peanut consumption habits, verifying self-reported data by measuring peanut residue in dust from their beds—a technique validated by previous LEAP research.

Results showed that 15.4% of participants from the early peanut-avoidance group and only 4.4% from the early peanut-consumption group had peanut allergies at age 12 or older. This translates to 38 out of 246 participants in the avoidance group and 11 out of 251 in the consumption group. Thus, early and regular consumption of peanuts reduced the risk of developing a peanut allergy in adolescence by 71% compared to avoiding peanuts early on.

Interestingly, the study also revealed that children in the peanut-consuming group did not need to continue eating peanuts consistently throughout childhood to maintain their allergy protection. While these children did eat more peanut products overall, their consumption varied, and included periods of abstaining from peanuts altogether. This indicates that the protective effects of early peanut consumption are long-lasting and do not require continuous exposure to peanuts during later childhood and early adolescence.

This study provides crucial insights into peanut allergy prevention, suggesting that a simple dietary intervention in early childhood can have lasting benefits. With peanut allergies being a significant concern for many families, these findings could lead to a substantial decrease in the prevalence of this condition if widely adopted. As Dr. Marrazzo emphasized, implementing this strategy could prevent tens of thousands of peanut allergy cases among the millions of children born each year in the United States.

By introducing peanut products to infants, parents and caregivers can significantly reduce the risk of their children developing peanut allergies, offering a practical and effective approach to allergy prevention.

For detailed advice on how to safety introduce peanut into an infant’s diet, consult the Addendum Guidelines for the Prevention of Peanut Allergy in the United States.

The NIAID-funded Immune Tolerance Network (ITN) conducted LEAP, LEAP-On and LEAP-Trio under the leadership of Gideon Lack, M.D. Dr. Lack is a professor of pediatric allergy at King's College London and head of the Children's Allergy Clinical Academic Group in the KHP Institute of Women and Children's Health at Evelina London.

Note: Materials provided above by Murdoch Childrens Research Institute. Content may be edited for style and length.