For decades, as food allergy rates climbed, experts recommended that parents avoid exposing their infants to common allergens. But a landmark trial in 2015 found that feeding peanut products to babies could cut their chances of developing an allergy by over 80 percent. In 2017, the National Institute of Allergy and Infectious Diseases formally recommended the early-introduction approach and issued national guidelines.

The new study, published Monday in the journal Pediatrics, found that food allergy rates in children under 3 fell after those guidelines were put into place — dropping to 0.93 percent between 2017 and 2020, from 1.46 percent between 2012 and 2015. That’s a 36 percent reduction in all food allergies, driven largely by a 43 percent drop in peanut allergies.