According to the latest data released by the Centers for Disease Control and Prevention (CDC) in 2021, nearly 6% of children in the United States are affected by food allergies, with this proportion exhibiting an upward trend as children age: the allergy rate among children aged 0-5 is 4.4%, rising to 5.8% for those aged 6-11, and reaching as high as 7.1% among adolescents aged 12-17.
Despite the ongoing rise in food allergy incidence that has sparked widespread public concern, the scientific community has made numerous encouraging advancements in the field of food allergy prevention in recent years.
Significant changes have been observed in current infant feeding practice guidelines, which now recommend the early introduction of high-allergen foods such as eggs, nuts, and fish. This shift is based on compelling evidence suggesting that delaying the introduction of solid foods beyond 4 to 6 months or avoiding potential allergenic foods may actually increase the risk of food allergies in infants.
Among the various studies, the prevention of peanut allergies has garnered particular attention. Notably, the Learning Early About Peanut Allergy (LEAP) study was a landmark randomized, open-label, controlled trial. This study evaluated the prevalence of peanut allergies in infants aged 4 to 11 months who had existing allergies (such as egg allergy, severe eczema, or both). The results demonstrated that introducing and continuing to consume age-appropriate peanut products during the first year of life significantly reduced the number of high-risk children who developed peanut allergies at age 5.
The findings of the LEAP study prompted the addition of an appendix to the “Guidelines for the Diagnosis and Management of Food Allergies in the United States” published in 2010. Furthermore, in 2017, the National Institute of Allergy and Infectious Diseases (NIAID) released the “Addendum Guidelines for the Prevention of Peanut Allergy.” These guidelines provide specific recommendations or suggestions (depending on the strength of the evidence) for introducing peanut-containing foods, tailored to infants with severe or mild-to-moderate eczema, egg allergies, or both.
For infants with existing egg allergies and/or severe eczema, the guidelines recommend conducting a peanut allergy test before introducing peanut-containing foods. Additionally, infants with higher food allergy risks or existing food allergies may require supervision and guidance in a clinical setting to safely introduce solid foods.
While more evidence is still needed to confirm the association between the introduction of other high-allergen foods and risk reduction, authoritative bodies (including the 2020-2025 Dietary Guidelines for Americans) have reached a consensus: there is no evidence to suggest that delaying the introduction of allergic foods (aside from introducing other complementary foods) helps prevent food allergies. However, to ensure infant safety, it is advisable to introduce other solid foods first and gradually introduce potentially allergic foods.
When deciding the timing for introducing solid foods, close attention should be paid to infants’ developmental readiness signs, with the general recommendation being to start between 4 and 6 months of age. Infant feeding guidelines continue to encourage breastfeeding as the sole source of nutrition for the first 6 months of life, with the timely introduction of complementary foods. However, for some practitioners and parents, the recommendations regarding the introduction of potential allergenic foods are still relatively novel, leading to potential variations in the acceptance and implementation of feeding practices.
For instance, a survey of healthcare practitioners in Canada found that physicians and pediatricians tended to recommend a longer window (between 6 months and 1 year) for introducing allergic foods compared to allergists, who were more likely to suggest an earlier introduction (between 4 and 6 months).
Another survey assessed parents’ attitudes towards feeding habits for infants from birth to 24 months. The results revealed that approximately half of the parents expressed dissatisfaction with the guidance on transitioning to solid foods. They lacked knowledge about where to find reliable advice, which foods to introduce, and when to introduce them, which was deemed a concerning issue. Although the survey communicated the risks of allergic reactions, this information seemed to cause more anxiety among parents of infants under 6 months. Most surveyed parents began introducing solid foods between 6 and 12 months of age; however, mothers were more likely to start feeding infants solid foods at 6 months compared to fathers who waited until 12 months.
During this critical life stage, helping parents and other caregivers correctly introduce nutritious and age-appropriate foods is crucial to minimizing the risk of food allergies. As part of an interdisciplinary team, registered dietitians can play a pivotal role in helping families determine appropriate methods to integrate culturally relevant foods while still ensuring adequate nutrition to support infants’ health and growth. Through scientific feeding guidance and personalized nutrition advice, we can collectively create a safer and healthier dietary environment for infants.
