Peanut allergies have plummeted in children, study shows

Food allergies in children dropped sharply in the years after new guidelines encouraged parents to introduce infants to peanuts, a study has found.

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 peanuts to babies could cut their chances of developing an allergy by over 80%. 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 younger than 3 fell after those guidelines were put into place — dropping to 0.93% between 2017 and 2020, from 1.46% between 2012 and 2015. That’s a 36% reduction in all food allergies, driven largely by a 43% drop in peanut allergies.

The study also found that eggs overtook peanuts as the No. 1 food allergen in young children.

The study did not examine what infants ate, so it does not show that the guidelines caused the decline. Still, the data is promising. While all food allergies can be dangerous, 80% of people never outgrow a peanut allergy.

“We’re talking about the prevention of a potentially deadly, life-changing diagnosis,” said Dr. Edith Bracho-Sanchez, a pediatrician at Columbia University Irving Medical Center in New York, who was not involved with the study. “This is real world data of how a public health recommendation can change children’s health.”

Scientists don’t fully understand what causes food allergies, but some believe that higher rates of C-section deliveries, early childhood exposure to antibiotics and our increasingly sanitized environments may play a role, said Jeanna Ryan, a physician assistant at University of Utah Health.

However, scientists have a working picture of how allergies might develop. Allergens first encountered through the skin — especially broken or inflamed skin — can prompt the immune system to mistake them for threats, said Dr. David Hill, a pediatric allergist at Children’s Hospital of Philadelphia who led the new study. But when food allergens are introduced through the gut, it can build tolerance.

For the past decade, studies have shown that introducing allergenic foods in infancy, as the immune system is developing, can help the body recognize food proteins as harmless, Hill said.

The latest national guidelines, established in 2021, recommend introducing common food allergens to all infants 4 to 6 months of age. Early introduction to the nine commonly allergenic foods a couple of times a weekcan help train an infant’s immune system.

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