Prevention of Food Allergies

LEAP and EAT Studies

A landmark study published in 2015 called “Learning Early About Peanut Allergy (LEAP),” revolutionized our understanding of the development of peanut allergy in children and transformed the guidance that pediatricians and allergists/immunologists give to parents about when to introduce peanut foods to children at high risk for food allergies.

Babies enrolled in the LEAP study were at high risk for developing peanut allergy because they already had severe eczema (i.e., atopic dermatitis), egg allergy, or both. Beginning at age 4-10 months, babies in the LEAP study were split into 2 groups and were followed for 4 years. One group avoided peanut foods, while the other group was given age-appropriate peanut foods several times a week. By age 5, the children who had begun eating peanut as infants were much less likely to be allergic to peanuts. Eating peanut foods early and regularly reduced the risk of peanut allergy by more than 80% compared to the group of children who avoided peanuts.

In a follow-up study called “Persistence of Oral Tolerance to Peanut (LEAP-On),” the results showed that peanut tolerance promoted by early introduction to peanut foods could be long-lasting. Children who ate peanuts from infancy to age 5 and then avoided peanuts from age 5 to age 6 were still 74% less likely to have peanut allergy than children who had consistently avoided peanut foods from infancy to age 6.

Does introducing allergenic foods early in life put a baby at a greater risk for food allergy?

A study published in 2016, called the “Enquiring About Tolerance (EAT)” study randomly assigned 1,300 breastfed infants to 1 of 2 treatment groups at age 3 months. One group was introduced to a sequence of 6 allergenic foods (i.e., milk, peanut, egg, sesame, fish and wheat), while the other group continued breastfeeding exclusively until age 6 months.

The EAT study revealed that rates of allergy to the 6 foods were not significantly different when the early introduction group and the exclusively breastfed group were compared at ages 1 and 3. This showed that early introduction of allergenic foods did not increase a baby’s risk for food allergy.

Does early introduction of egg products reduce the risk of developing egg allergy too?

In 2019, a new analysis of the EAT study data showed that early introduction of allergenic foods did protect against food allergies for some children at high risk. Children were considered at high risk if their blood tests showed specific IgE antibodies to the foods. They were considered sensitized. These specific IgE antibodies mediate allergic reactions.

  • Compared to exclusive breastfeeding, early food introduction reduced the likelihood that a baby would be sensitized to 1 or more of the 6 foods. It also made it less likely for the baby to develop an allergy to 1 or more of the 6 foods.
  • Early introduction of peanuts lowered the risk of developing peanut allergy in babies sensitized to peanuts. This finding is consistent with the LEAP study.
  • Early introduction of egg lowered the risk of developing egg allergy in babies sensitized to egg. Early introduction of foods including egg also provided protection against egg allergy in babies with moderate or severe eczema at age 3 months.
  • For babies who were not sensitized to any of the 6 foods at the beginning of the study, the risk of developing an allergy to 1 or more of the foods was similar in both the early introduction and exclusive breastfeeding groups.

These new findings from the EAT study indicate that early introduction of egg can provide protection against egg allergy for at least some children at high risk for developing egg allergy.

Guidance from American Academy of Allergy, Asthma & Immunology (AAAAI), American College of Allergy, Asthma & Immunology (ACAAI), and the Canadian Society for Allergy and Clinical Immunology:

To prevent peanut and/or egg allergy, both peanut and egg should be introduced around 6 months of life, but not before 4 months. Screening before introduction is not required. Other food allergens should be introduced around this time as well. Upon introducing complementary foods, infants should be fed a diverse diet, because this may help foster the prevention of a food allergy. Maternal exclusion of common allergens during pregnancy and/or lactation as a means to prevent food allergy is not recommended.

The board certified allergy doctors of Black & Kletz Allergy have had over half a century of experience dealing with food allergies in both children and adults. Black & Kletz Allergy has 3 office locations in the greater Washington, DC, Northern Virginia, and Maryland metropolitan area. The allergists at Black & Kletz Allergy diagnose and treat individuals with allergies (e.g., hay fever, food allergies, medication allergies), asthma, hives, swelling episodes, eczema, contact dermatitis, insect bites, bee sting allergies, sinus disease, and immunologic problems. We have offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA and have on-site parking at each location. The Washington, DC and McLean, VA offices are Metro accessible and there is a free shuttle that runs between our McLean, VA office and the Spring Hill metro station on the silver line. Please call us to make an appointment or alternatively, you can click Request an Appointment and we will respond within 24 hours by the next business day. Black & Kletz Allergy has been striving to provide high quality allergy and asthma care to the residents of the Washington, DC metro area for more than 50 years. We are committed to continue delivering state-of-the-art allergy and asthma care in the future.