An exciting new study on food allergy was recently published in the New England Journal of Medicine. This study, called the LEAP (Learning Early about Peanut Allergy) study, has been much anticipated in the allergy world. It basically reinforces recent recommendations about how we introduce highly allergic foods to our children. In the past, delaying introduction of milk, eggs and peanuts was the norm. Newer information has suggested that we should not delay introduction of these highly allergenic foods in most infants, and this study confirms these recommendations.
The LEAP study involved over 600 children who were considered high risk for peanut allergy (moderate-severe eczema and/or egg allergy). After skin testing these children and performing oral challenges, they were placed into two groups; one group ate high dose peanut products (equivalent of about 8 peanuts) 3 times per week and the other group avoided peanut completely. They then re-evaluated the prevalence of peanut allergy at age 5. There was a remarkable difference in the prevalence of peanut allergy between these 2 groups, with the group eating peanut regularly having significantly less peanut allergy (13.7% in the avoidance group and 1.9% in the consumption group). Some of these children even had evidence of allergic antibodies to peanut at the beginning of the study, but no clinical reaction (sensitization). Those children sensitized to peanut, but who regularly ate peanut over the course of the study had a 70% reduction in the prevalence of peanut allergy as compared to those children sensitized to peanut, but who completely avoided peanut. This indicates that we may be able to prevent the development of peanut allergy in children who have no evidence of peanut allergy, as well as in children who have evidence of allergic antibodies to peanut, but no clinical reaction.
This study should still be interpreted with caution for several reasons. Oral food challenges were done prior to introducing peanut and some kids had reactions. Also, it was limited to children with eczema and/or egg allergy. What about children with other food allergies or other risk factors? Do kids have to eat high dose peanut or can lower doses less frequently provide the same benefit? What happens down the road over the next several years? There is another study in the works, LEAP-On, to answer some of these questions. For now, it is important to remember this this study does not promise a cure for peanut allergy, but shows that we may be able to prevent the development of peanut allergy, at least in some patients. Very exciting stuff!