Early Peanut Introduction Shows Significant Reduction in Childhood Allergies, Study Finds

Early introduction of peanuts to infants could significantly reduce the risk of developing allergies, according to groundbreaking new research published in the medical journal Pediatrics.

The study reveals that exposing children to peanuts between 4 and 11 months of age—rather than waiting until age 3 as previously recommended by the American Academy of Pediatrics—has led to a substantial 43% drop in peanut allergy diagnoses in children under 3 years old.

“New onset peanut allergy dropped by 43% in kids under 3,” said Dr. David Hill from the Division of Allergy and Immunology at the Children’s Hospital of Philadelphia, one of the study’s authors. He noted that new-onset food allergies overall decreased by 36% in that same age group.

Peanut allergies represent one of the primary causes of serious allergic reactions in children. These reactions occur when the immune system overreacts to peanuts by producing immunoglobulin E (IgE), potentially leading to anaphylaxis—a severe and sometimes life-threatening allergic response. Approximately 4% of children are affected by food allergies that can cause immediate and dangerous symptoms including hives, difficulty breathing, swelling and vomiting.

The findings mark a significant shift in understanding how to prevent childhood food allergies. Before 2015, standard medical practice cautioned parents against exposing young children under 3 to peanuts. That guidance changed following the landmark Learning Early About Peanut Allergy (LEAP) trial, which found that exposing high-risk infants with severe eczema or egg allergies to peanuts between 4 and 11 months old could reduce peanut allergy risk by an astonishing 81%.

“It just seems like there’s this window of tolerance during early infancy, so if we introduced the foods during that window, you will prevent food allergy,” explained Dr. Susan Schuval, chief of the Division of Pediatric Allergy and Immunology at Stony Brook Children’s Hospital in New York, who was not involved in the study. “If you wait until after that window, the child will be more predisposed to having a food allergy.”

Based on the LEAP trial results, leading pediatric allergy and immunology organizations revised their clinical practice guidelines in 2015 and 2017, permitting early peanut exposure for children at high risk. In 2021, the guidelines were updated again to encourage introduction of peanut, egg and other major food allergens as early as 4 to 6 months for all children, including those without prior reactions.

Dr. Hill and his research team analyzed electronic health records from multiple clinics across several states to evaluate the effects of the revised 2015 and 2017 guidelines. Their analysis did not include the most recent 2021 revisions. For at least two years after the 2015 guidance change, they documented a 27% decrease in peanut allergies and a 38% decrease in food allergies generally.

Even more promising results followed the 2017 guideline change, with peanut allergies dropping by 43% and overall food allergies decreasing by 36% compared to pre-2015 rates among children observed for at least a year. The study also noted that egg allergies were more common than peanut allergies across the analyzed data.

“Everyone has been wondering whether these landmark public health interventions have had an impact on reducing rates of IgE-mediated food allergies in the United States,” said first author Stanislaw Gabryszewski, an attending physician in the Division of Allergy and Immunology at the Children’s Hospital of Philadelphia. “We now have data that suggest the effect of this landmark public health intervention is occurring.”

While early exposure may not completely eliminate all food allergies, the researchers emphasize that the significant reduction in diagnoses is promising. They stress the importance of consistent early introduction in clinical practice settings to maximize positive outcomes.

Dr. Hill expressed hope that these findings will increase awareness that early allergen introduction is both safe and effective. “Our findings have relevance [for] those of us who treat patients [and] those caring for infants—and more awareness, education and advocacy could further increase the positive results we observed in this study,” he said.

Medical experts acknowledge that not all parents feel comfortable with these revised guidelines. “Not everyone has followed those guidelines, but this is further evidence that this early introduction is effective at preventing food allergies,” Dr. Schuval noted.

Parents are encouraged to consult with their pediatrician before introducing potential allergens to their infants. The researchers indicate that future studies will be needed to investigate how timing, dosage and frequency of exposure might further enhance protection against food allergies.