Early Exposure to Peanuts Can Help Reduce the Risk of Developing Allergies in Children
The current understanding is that exposing young children to peanut protein may reduce the likelihood that they develop peanut allergies as they grow up. The National Institute of Allergy and Infectious Diseases (NIAID) issued guidelines recommending early introduction of peanut-containing foods to infants in 2017.
“Over the past two to three decades, we have learned a lot, and allergists and pediatricians have changed their thinking and recommendations as new evidence and studies point us one way or another,” says Scott Sicherer, MD, Director of the Elliot and Roslyn Jaffe Food Allergy Institute at Mount Sinai Kravis Children’s Hospital, who was also involved in the development of the NIAID 2017 guidelines.
How might peanut allergies—or food allergies in general—develop in people, and how might introducing peanuts at a young age help reduce this allergy risk? How can parents safely introduce peanut products to their young children? Dr. Sicherer explains the science and research behind this topic.
Scott Sicherer, MD, Director of the Elliot and Roslyn Jaffe Food Allergy Institute, and Chief of the Serena and John Liew Division of Pediatric Allergy and Immunology in Mount Sinai’s Department of Pediatrics.
Do we know what causes peanut—or food—allergies in general?
Environment can include diet, the way we live, where we live, what the child and household are doing. Is there a dog in the house? How are we using antibiotics and soaps? Was the baby born by cesarian section? There is evidence that seems to link higher rates of allergies to babies born by C-section. The list could go on and on.
The genetics side has also been extensively studied. We had done studies at Mount Sinai on the role genetics might play in peanut allergies, comparing identical and fraternal twins, and found that genetics has a lot to do with it. We found a lot of heritability of allergies, where having a family history of it is also a risk factor for the baby.
Has the rate of peanut allergies in children increased over time?
In 1997, we found the reported rate for children with a peanut allergy to be 0.4 percent, or1 in 250 children. In adults, that rate was 0.7 percent, or 1 in 150 adults. In 2002, that rate for children doubled to 0.8 percent, or 1 in 125 children, and the rate for adults was roughly the same, at 0.6 percent.
In 2008, we did the survey again, and I was shocked by the number for children, which was 1.4 percent, or 1 in 70 children. That’s almost a tripling from 1997, while the rate for adults in 2008 remained the same.
At first, I wondered if there was an issue with our survey. But it should have been accurate because our method was the same across the years. I was convinced when our 2008 findings were matched with studies coming out of Australia, Canada, and England at that time, which were reporting prevalence rates of more than 1 percent for children as well. So it did seem there was a real increase between 1997 and 2008.
What might have caused this increase?
What if the ground rules changed quickly, and the immune system was faced with relatively sudden changes that made it harder to adapt and attack the right potential dangers entering our body?
The “hygiene hypothesis” posits that our modern, industrialized society could be a cause for the increased allergy rates. Exposure to fewer or different germs, while making us healthy in some ways, could result in the immune system going out of balance and attacking things it should be ignoring, like allergens including pollens, animal dander, and foods. Add to that the many other changes in our modern world, we have a perfect storm for trouble.
Furthermore, back in the 1990s and 2000s, the prevailing understanding—based on early studies—was for mothers, if they had babies who were at high risk of developing allergy, to avoid allergens during pregnancy and breastfeeding. They were also recommended to avoid feeding babies cow milk until age one, eggs until age two, and fish and nuts until age three—these were from the American Academy of Pediatrics (AAP) in the year 2000.
By 2008, there were new studies showing that delayed introduction of allergenic foods might increase the risk of developing allergies. Around that time, I joined the AAP committee to rescind the previous recommendations.
What studies support early introduction of peanuts for reducing allergy risk?
This prompted a landmark clinical trial, substantially funded by NIAID, called the Learning Early About Peanut (LEAP) study. The study assessed how infants ages 4 months to 11 months old with eczema and/or egg allergy—and thus at high risk for developing peanut allergies—would fare if fed peanut snacks until 60 months of age, compared with a group that avoided peanut products. The results, published in The New England Journal of Medicine in 2015, found that the prevalence of peanut allergies among those following the advice was 17.3 percent in the avoidance group, whereas the consumption group’s prevalence was 0.3 percent.
What do medical professionals and organizations recommend now?
When the LEAP study results came out, NIAID updated its guidelines in 2017—Dr. Sampson and I were authors—this time encouraging early peanut introduction, and with instructions about how to do it. There’s a resource called Appendix D that describes how to get peanuts safely into the diet, because peanuts and peanut butter can be a choking hazard for babies. Professional medical organizations, including the AAP and the American Academy of Family Physicians, have since adopted similar recommendations on the early introduction of peanuts. Additional guidelines extrapolate the advice to other common allergens—like milk, egg, and tree nuts—for them to be included in the diet in infant-safe forms on a regular basis, essentially treating solid foods as equivalent whether they are common allergens or not.
How can I begin introducing peanuts early for my child, safely?
The bottom line is: If your baby is otherwise healthy and hasn’t had any problems with food allergies, typical food allergens can be added to a diverse diet, just like any other food in its safe form.
However, if your baby is already showing signs of allergy or problems with various foods, absolutely talk to your pediatrician, who may work with an allergist to fine-tune a path forward. The exciting thing is we do have treatments for food allergy now, and there are many great things happening in the field. Talking to your doctor can help your child lead a healthy, fulfilling life without the overhanging fear of triggering food allergies.
Appendix D instructions for home feeding of peanut protein for a low-risk infant
| General instructions | Feeding instructions |
| 1. Feed your infant only when they are healthy; do not feed if they have a cold, are vomiting, or have diarrhea or other illnesses. | 1. Prepare a full portion of the peanut-containing food. |
| 2. Give the first peanut feeding at home, not at a daycare center or restaurant. | 2. Offer your infant a small part of the peanut serving on the tip of the spoon. |
| 3. Make sure at least one adult is able to pay full attention to the infant, without distractions. | 3. Wait 10 minutes. |
| 4. Make sure to spend at least two hours with the infant after feeding, to watch for any signs of allergic reaction. | 4. If there’s no allergic reaction after the small taste, then slowly give the remainder of the peanut-containing food at the infant’s usual eating speed. |
