Over the past decade, studies have shown that the early introduction of common food allergens can reduce the risk of developing food allergies. Additional data and approaches building on this research were presented at the recent 2026 AAAAI Annual Meeting.

Following these presentations, featured expert Jacob D. Kattan, MD, was interviewed by Conference Reporter Associate Editor-in-Chief Mona Shah, PharmD. Clinical perspectives from Dr Kattan on these findings are presented here.

Approximately 20 to 30 years ago, we used to advise people to delay introducing some allergenic foods because we believed that this would help prevent allergic reactions. Then, approximately 10 years ago, the LEAP study was published. It was groundbreaking because it looked at the early introduction of peanuts into the diets of infants who were at high risk for peanut allergies, such as those with severe eczema and/or existing egg allergies. The children participating in the study who were randomly assigned to consume peanuts were instructed to do so 3 times weekly for 5 years. The LEAP study showed that the early introduction and regular incorporation of peanuts into children’s diets could greatly reduce the incidence of peanut allergies. As a result, the National Institute of Allergy and Infectious Diseases (NIAID) guidelines changed to say that we should target children during infancy, starting as young as 4 to 6 months of age, especially if they are at high risk for food allergies.

And that led us to think about other foods. Could we prevent allergic reactions to other common food allergens? In the EAT study, for example, investigators looked at introducing a number of food allergens in breastfed infants starting at 3 months of age. They looked at cow’s milk, eggs, sesame, fish, and wheat, as well as peanuts. However, in this study, early introduction did not lower the incidence of allergies to all of those allergens; it just lowered the incidence of peanut and egg allergies, perhaps because the other foods were more challenging to regularly incorporate into the diets of infants and children in the same way at such a young age.

In subsequent studies, we learned more about the barriers to the early introduction of common food allergens. Some allergists and pediatricians were not very familiar with the LEAP study, and there was concern that introducing these food allergens into children’s diets could trigger allergic reactions. In 2025, the results of a study published in Pediatrics actually confirmed a decreased incidence of peanut allergies in the years following the LEAP study despite these barriers. So, our challenge now is to reach more people with this information and to find effective ways to expand this prevention to other allergens.

Several studies presented at the 2026 AAAAI Annual Meeting examined the early introduction of common food allergens beyond peanuts and eggs. For instance, the CANDO study by Michael Yang and colleagues addressed introducing food allergens—specifically peanuts, eggs, cow’s milk, and cashews—by 4 to 6 months of age (abstract 683). Ultimately, infants enrolled in the study were found to consume more allergenic foods than those who followed standard feeding practices, although they were also found to consume fewer vegetables and fruits.

Another study from AAAAI 2026 examined the early introduction of peanuts in an underserved community using kits that included bilingual educational materials, feeding supplies, and infant-safe peanut products (abstract 229). Kaley Desher, MD, et al found that this low-cost community-based initiative was associated with higher rates of early peanut introduction.

The TreEat study by Vicki McWilliam, PhD, and colleagues was also presented at this year’s AAAAI meeting (abstract L15). It examined the early introduction of tree nuts, specifically targeting infants with peanut allergies. The study design compared the efficacy and safety of the hospital-based multi-nut introduction of almonds, cashews, hazelnuts, and walnuts with the home-based introduction of these individual tree nuts. Interestingly, researchers did not find significantly different rates of tree nut allergies between the 2 groups. I would have thought that the hospital-based oral food challenge would have been more successful. And so, I think there are additional studies that need to be done, including the analyses to determine whether the multi-nut oral food challenge led to the earlier introduction of tree nuts, even if it did not prevent tree nut allergies per se.

It takes time to familiarize families with the early introduction of allergenic foods. It is not the kind of discussion that you can fit into a 15- or 20-minute visit that also involves performing a history and skin testing, as well as reviewing how to treat an allergic reaction. It is a longer conversation that must be tailored to each family, particularly families with children who have feeding difficulties or aversions to certain food textures.

Overall, there has been a paradigm shift over the past decade in the field of allergy and immunology regarding the early introduction of allergenic foods to help prevent food allergies. Looking ahead, I think that we need to design more studies on the early introduction of common food allergens beyond peanuts and eggs. Additionally, we need to develop ways to introduce multiple allergenic foods and regularly incorporate those allergens into the diets of young infants who are not yet consuming many solid foods.