Early Introduction of Peanuts to Infants Shows Significant Reduction in Food Allergies, Study Finds

In a striking reversal of long-held medical guidance, researchers have confirmed that introducing peanuts to infants as early as 4 months of age can significantly reduce the risk of developing food allergies, according to a comprehensive study published in October 2025.

The research, led by the Children’s Hospital of Philadelphia, analyzed medical records from dozens of pediatric practices across the United States and found that early introduction of peanuts resulted in a 27% decrease in peanut allergy diagnoses among children and a 38% decrease in overall food allergies.

“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, M.D., Ph.D., 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.”

The study, published in Pediatrics, the journal of the American Academy of Pediatrics, examined a two-year period following updated guidance from the National Institute of Allergy and Infectious Diseases, which began advising parents to introduce peanuts earlier in a child’s development.

This recommendation stemmed from a groundbreaking 2015 study—the Learning Early About Peanut Allergy (LEAP) trial—which discovered that exposing infants with severe eczema or egg allergies to peanuts between 4 and 11 months of age could reduce peanut allergy risk by an astonishing 81%.

The guidelines underwent further refinement in 2021, expanding to encourage introduction of peanuts, eggs, and other major food allergens as early as 4 to 6 months for all children, including those without prior allergic reactions.

Interestingly, the research also noted that eggs have now surpassed peanuts as the most common food allergen among the children studied. Other common food allergens include milk and wheat.

“If confirmed, these findings would represent a meaningful public health advance—affirming that clinical research, when coupled with clear guidelines and committed dissemination, can indeed shift the trajectory of childhood food allergy,” the study authors wrote.

This represents a complete paradigm shift from previous medical advice. Historically, parents were told to avoid introducing peanuts and other potential allergens during the first few years of a child’s life, based on the belief that early exposure might increase allergy risk.

The implications of these findings are significant, as peanut allergies can trigger severe, life-threatening reactions in some children, including difficulty breathing, throat swelling, and dangerous drops in blood pressure. These reactions require immediate treatment with epinephrine, a life-saving allergy medication.

Dr. Susan Schuval, chief of the Division of Pediatric Allergy and Immunology at Stony Brook Children’s Hospital in New York, noted that while not all parents have followed the updated guidelines, “this is further evidence that this early introduction is effective at preventing food allergies.”

Despite the promising results, the researchers acknowledged several limitations to their study. It only included data through early 2019, missing the impact of the 2021 guidance that recommended early introduction of multiple allergens regardless of risk. Additionally, the research relied on allergy diagnoses from electronic health records, which may not capture all cases, and didn’t track individual feeding patterns.

The researchers also emphasized that as an observational study, it can only show association rather than definitively proving cause and effect. Other factors may influence allergy development.

Health experts acknowledge that not all parents may feel comfortable with these revised guidelines. Medical professionals encourage parents to discuss any concerns with their pediatrician before introducing potential food allergens to their infants.

The study authors conclude that their findings “are supportive of efforts to increase education and advocacy related to early food introduction practices,” suggesting that proper implementation of these guidelines could significantly reduce the prevalence of food allergies in children nationwide.