A LEAP Forward For Peanut Allergy Prevention?

Peanuts2Evidence is growing that introducing peanuts in infancy – instead of delaying consumption – is beneficial in preventing peanut allergy. 

However, it remains important that parents of children at high risk for peanut allergy — for example, egg allergy symptoms or severe eczema — consult with their child’s pediatrician or board-certified allergist before introducing peanut into their child’s diet. Certain children will need to be closely supervised and monitored as peanut is introduced.

In a continuation of the landmark Learning Early About Peanut (LEAP) study, researchers reported that high-risk children who eat peanuts early in life – and follow a set protocol for regular consumption – are less likely to develop peanut allergy compared to those who deliberately avoided peanut, even if they stop eating peanuts for up to one year. The latest research – called the LEAP-On study – was announced at the American Academy of Allergy, Asthma & Immunology (AAAAI) annual meeting March 4-7 in Los Angeles. 

Researchers are calling for additional studies to 1) measure the frequency and amount of peanut that needs to be consumed in early childhood to prevent the development of an allergy, and 2) establish whether peanut consumption over many years is needed to maintain this protection against allergy.

A basic conclusion of the original LEAP study was that regular consumption of small amounts of peanut in infants at high risk for peanut allergy lessened the risk of developing peanut allergy. In LEAP-On, participants in both groups of the LEAP study, those who ate peanut as infants and those who avoided peanuts were both asked to further avoid peanut for one year starting at age 5. One year later, there was not a significant increase in peanut allergy in either group.

The LEAP-On study also found peanut allergy continued to be significantly more prevalent in the LEAP infants who did not consume peanuts.

“LEAP-On shows the benefits from early peanut introduction were not temporary as there was no difference in rates of developing peanut allergy after one year of peanut avoidance,” says Matthew Greenhawt, MD, MBA, MSc, allergist and immunologist with Children’s Hospital Colorado. “The rate of allergy within the group who initially consumed peanut and then discontinued also did not significantly increase.”

“The study suggests the development of tolerance may be permanent,” adds Stanley Fineman, MD, allergist and immunologist at Atlanta Allergy & Asthma and past president of the American College of Allergy, Asthma & Immunology (ACAAI).

Questions remain, however.

“Reliability of this study for infants who may start early peanut introduction and then discontinue after a shorter duration of consumption is unclear, as is the true nature of tolerance,” Dr. Greenhawt says. “Should this be measured by ability to tolerate peanut after a prolonged discontinuation, or by intermittently consuming peanut from the beginning as opposed to a strict measured quantity per week? These are questions future studies must address.”

What about exposing infants to other allergenic foods such as egg, cow’s milk, fish, wheat or sesame? The Enquiring About Tolerance (EAT) study, published last week in The New England Journal of Medicine and presented at AAAAI’s annual meeting, evaluated breastfed infants exposed to those allergens. 

Overall, results showed a very small reduction in onset of food allergy among infants with early exposure, compared to those without exposure – but the study was deemed inconclusive because some parents did not feed the allergens to their children on a regular basis, per the study protocol.

“There are numerous positives that can be taken away from the EAT results,” Dr. Greenhawt says. “Foremost, there does not appear to be any increased rate of food allergy development from feeding these allergens early – reinforcing prior guidelines that discouraged any delay in the introduction of complementary foods to prevent allergy.

“Secondly, among those families strictly complying with the peanut and egg introduction protocols, there were small, significant reductions in the rate of peanut and egg allergies among those introducing peanut and egg early. So these results are very encouraging.”

Adds Dr. Fineman: “More research will need to be done. The good news for parents of children with food allergy is that there is new research and a search for an effective treatment may be closer than we previously thought.”

Update to National Food Allergy Guidelines

Last year, following the introduction of the LEAP study, the National Institute of Allergy and Infectious Diseases (NIAID) convened an expert panel to consider an update to the 2010 Guidelines for the Diagnosis and Management of Food Allergy in the United States.

This year, the panel drafted a supplement to the guidelines to address peanut allergy prevention based on the LEAP study. NIAID is seeking public comment on the draft addendum through April 18. To review the draft and provide comments.