A decade after a landmark study showed that feeding babies peanut products can prevent the development of potentially life-threatening allergies, new research reveals the consequences of that change.
Peanut allergies began to decline in the United States after guidelines published in 2015 revolutionized medical practice by recommending the introduction of the allergen into the diet of babies starting at four months. The rate of allergies in children aged 0 to 3 years fell by more than 27% after the guidelines were first published in 2015, and by more than 40% after they were expanded in 2017.
“It’s extraordinary,” said David Hill, an allergist and researcher at Children’s Hospital of Philadelphia and author of a study published Monday in the medical journal Pediatrics. Hill and her colleagues analyzed electronic medical records from dozens of pediatric practices to track food allergy diagnoses in young children before, during and after the guidelines were published.
“Today I can tell you that there are fewer children with food allergies than there would have been if we had not started this public health initiative,” he added.
Since 2015, about 60,000 children have avoided food allergies, including 40,000 who would otherwise have developed a peanut allergy. Still, about 8% of children have food allergies, including more than 2% with peanut allergies.
Peanut allergy occurs when the body’s immune system mistakenly identifies peanut proteins as harmful and releases chemicals that cause allergic symptoms, such as hives, respiratory symptoms, and sometimes life-threatening anaphylaxis.
For decades, doctors had recommended delaying the introduction of peanuts and other foods that can cause allergies into children’s diets until age 3. But in 2015, Gideon Lack of King’s College London published the groundbreaking paper Learning Early About Peanut Allergy (LEAP).
Lack and his colleagues showed that introducing peanut products in childhood reduced the future risk of developing food allergies by more than 80%. Subsequent analyzes showed that protection persisted in approximately 70% of children into adolescence.
The study immediately led to new guidelines calling for the early introduction of peanuts, but implementation has been slow. According to surveys, only about 29% of pediatricians and 65% of allergists said they follow the expanded guidelines published in 2017.
Confusion and uncertainty about the best way to introduce peanuts in early childhood caused the delay, according to a commentary accompanying the study. At first, medical experts and parents alike wondered whether this practice could be adopted outside of strictly controlled clinical settings.
The data for the analysis came from a subset of participating medical centers and may not be representative of the entire U.S. pediatric population, said the commentary, led by Dr. Ruchi Gupta, an expert in childhood allergies at Northwestern University.
However, the new research offers “promising evidence that early allergen introduction is not only being adopted, but may be having a measurable impact,” the authors concluded.
Advocates for the 33 million people in the United States with food allergies welcomed signs that the early introduction of peanut products is becoming popular.
“This research reinforces what we already know and underscores a significant opportunity to reduce the incidence and prevalence of peanut allergy nationwide,” said Sung Poblete, executive director of the nonprofit Food Allergy Research & Education.
The study emphasizes current guidelines, updated in 2021, which recommend introducing peanuts and other food allergens between four and six months, without the need for prior testing or screening, Hill said. Parents should consult their pediatricians if they have any questions.
“It doesn’t have to be a large amount of food, but small amounts of peanut butter, milk-based yogurt, other soy-based yogurts and nut butters,” he said, “are very good ways to allow the immune system to be exposed to these allergenic foods safely.”
Tiffany Leon, 36, a registered dietitian in Maryland and director of FARE, introduced peanuts and other allergens early to her sons, James, 4, and Cameron, 2.
At first, Leon’s mother was surprised by the advice to feed babies such foods before age 3, she said. But he explained how science had changed: “As a dietician, I follow evidence-based recommendations (…) So when someone told me, ‘This is how it’s done now, these are the new guidelines,’ I thought, ‘Well, this is what we’re going to do.’”
