Researchers from Kings College in London are reporting that infants who have been introduced to peanuts early in life are less likely to develop peanut allergies, even if they stop eating peanut around the age of five.

The Persistence of Oral Tolerance to Peanut (LEAP-On) study results were presented at the AAAAI Annual Meeting in Los Angeles, March 4-7, 2016 and were published in the New England Journal of Medicine. They continued the work of the LEAP study, which had been presented at the 2015 AAAAI meeting.

“The aim of our study was to find out whether infants who had consumed peanut in the LEAP study would remain protected against peanut allergy after they stopped eating peanut for 12 months. LEAP-On clearly demonstrates that the majority of infants did in fact remain protected and that the protection was long-lasting,” lead author Gideon Lack, MD, explained.

In the follow-up study, participants were instructed to avoid peanuts for 12 months. The primary outcome was the percentage of participants with peanut allergy at the end of the 12-month period, when the participants were 72 months of age. Therefore, 550 participants from LEAP (out of a total of 628) were enrolled and asked to avoid peanuts for 12 months after completion of the LEAP study. Patients then participated in oral peanut challenges, food allergy questionnaires, skin prick tests (SPT) and blood tests (peanut-specific immune markers IgE and IgG4).

A total of 445 participants successfully avoided consuming significant amount of peanuts for the LEAP-On protocol. 90.4% (255/282) of peanut-consumers avoided peanuts and 69.3% (190/274) of peanut-avoiders continued to avoid peanuts.

The study found that at age 6, there was no statistically significant increase in allergy after 12 months of avoidance, in those who had previously consumed peanut during the LEAP trial (3.6% (10/274) at 60 months versus 4.8% (13/270) at 72 months). The study also found that peanut allergy continued to be significantly more prevalent in those who had avoided eating peanuts in the original LEAP study, than those who consumed (18.6% vs 4.8%).

“We concluded that in infants at high-risk for allergy in whom peanut was introduced in the first year of life, and continued until age 5, a 12-month period of peanut avoidance was not associated with a significant increase in peanut allergy. Overall, the study saw a 74% relative reduction in the prevalence of peanut allergy in those who consumed peanut compared to those who avoided,” Lack said.

It should be noted that the LEAP study design did not measure the minimum frequency or amount of peanut consumption that is required in early childhood to prevent an allergic response to peanut. Researchers are also calling for additional studies to establish whether the effects of early-life peanut consumption followed by continued consumption of peanut over many years maintains this protection against allergy.

“These findings are important because they demonstrate the potential for people to become tolerant to peanut, and not just desensitized,” said James R. Baker, Jr., MD, CEO and chief medical officer of FARE. “We are pleased to see that the results of the LEAP study have begun to make an impact through the updates to the National Institute of Allergy and Infectious Diseases clinical guidance for physicians, which will address the role of early consumption in prevention of peanut allergy, and we believe that the findings from LEAP-On provide additional evidence that will be helpful in further informing advice for new parents from their healthcare providers.”

It is very important to understand that introducing these foods is not something you should just do on your own, without appropriate medical evaluation. Doing so in children susceptible to peanut allergy puts your child at risk of having a severe, potentially life threatening reaction to peanut. Formal evaluation and consultation by an allergist is paramount in making sure this is the proper and safe choice to make before giving peanut to high-risk infants.

If your child is at risk of developing peanut allergy due to a family history of allergy or already having eczema and/or an egg allergy, please set up an appointment for allergy skin testing and to discuss the results of this study in more detail to determine if introducing peanut products into the diet is the right decision for your child.

Download April 2016 Newsletter