One decade after researchers discovered that feeding babies peanuts early could prevent dangerous allergies, new data shows the change is paying off.
A national study led by Dr. David Hill, a pediatric allergist at the Children’s Hospital of Philadelphia, found that peanut allergies have dropped by 43% since health experts began encouraging parents to introduce peanuts and other allergenic foods early in life.
The findings
The breakthrough began with the 2015 LEAP (Learning Early About Peanut Allergy) study, which overturned decades of advice telling parents to avoid giving babies peanuts. The research demonstrated that early exposure could actually train the immune system to tolerate peanuts rather than reject them.
Now, nearly 10 years later, the new analysis, published in the journal Pediatrics, shows that these findings are having a real-world impact.
About 60,000 children have avoided peanut allergy developments since the original guidance was first released in 2015.
“That’s a remarkable thing, right?” said Hill, per The Associated Press. “I can actually come to you today and say there are less kids with food allergy today than there would have been if we hadn’t implemented this public health effort.”
The study noted, however, that uptake of early food introduction varied. Surveys found that only 29% of general pediatricians and 65% of allergists fully endorse the 2017 peanut introduction guidelines. Following the 2021 updates, just 17% recommended introduction before seven months.
Understanding allergy development
The study focused on IgE-mediated food allergies, the most common cause of anaphylaxis in children and a factor in impaired quality of life. While peanut allergies have declined, rates of other allergens like egg allergies showed no significant change.
Jeanna Ryan, a physician assistant at University of Utah Health, told The New York Times that the exact cause of food allergies remains unclear. Factors such as higher rates of C-section deliveries, antibiotic use in infancy and increasingly sanitized environments may contribute to the development.
Hill noted that the way infants first encounter allergens influences immune responses. When allergens are first encountered through the skin, it can trigger the immune system to treat those allergens as threats, especially if introduced to broken or inflamed skin. However, if babies are exposed to allergens through the gut, it can teach the immune system tolerance.
“Our findings have relevance from those of us who treat patients to those caring for infants,” Hill said.
“More awareness, education and advocacy could further increase the positive results we observed in this study. Future studies could potentially explore specific feeding practices that help us better understand the timing, frequency and dose of foods that optimize protection against food allergies.”
The current guidelines published in Pediatrics recommend introducing common food allergens — including peanuts, eggs and milk — between 4 to 6 months of age.
Hill emphasized exposure doesn’t have to be large amounts.
“Little tastes of peanut butter, milk-based yogurt, soy-based yogurts and tree butters. These are really good ways to allow the immune system exposure to these allergenic foods in a safe way,” he said.
The study authors also emphasized that infants should be monitored for any signs of an allergic reaction after new foods are introduced, and that parents of infants with eczema or a family history of food allergies should consult health care providers.
The journal also notes that consistent, ongoing exposure may be important and that parents should follow the guidance of their child’s health care professionals while keeping up to date with evolving recommendations.