Exposing Kids to Peanuts Early May Prevent Allergy Later

But how soon is too soon? Learn the safe way—and the best age—to introduce peanut butter to your baby

father applying peanut butter on toast for a baby boy

When I was growing up, PB & J was a lunch box staple. But due to the increase in peanut allergies (which have quadrupled in recent years), many schools don’t allow children to take peanut products to school anymore for fear of anaphylaxis—a severe, potentially life-threatening allergic reaction. 

But the results from a 2015 study published in the New England Journal of Medicine found that exposure to peanut products may actually help decrease future peanut allergies—and bring PB & J sandwiches back as a lunchtime standard. 

What the research found 

The LEAP (Learning About Peanut Allergy) study released its groundbreaking data showing that introducing peanut butter to babies who were at least 4 months but less than 11 months of age decreased their chance of developing a peanut allergy. In the study, researchers found that kids who avoided peanuts until they were age 5 were up to seven times more likely to wind up with a peanut allergy than kids who ate peanuts at least three times a week. 

This helps shed light on the question of when to introduce peanut butter and peanut products to babies and children. 

Previously it was recommended that parents hold off on giving kids peanuts and peanut products until they reached 1 to 3 years of age. But as the number of cases of peanut allergies in children continued to grow, we doctors began to wonder if we were creating food allergies by holding off on potentially allergic foods. One striking example: In Israel, where babies and young children often eat a peanut snack called Bamba, the prevalence of peanut allergies was low. 

The LEAP study included just over 600 infants at high risk for peanut allergy, determined by whether they were already allergic to eggs or had eczema, which causes skin to become red and itchy. The researchers randomly assigned the children to either receive a peanut protein powder mixed with water three times a week, or to avoid peanut protein completely. They also tested the infants to see if their skin prick test to peanut was negative (not allergic) or mild. 

The results were shocking.  

In the children who were initially negative (did not have a peanut allergy), 13.7 percent of those who avoided peanut protein developed a peanut allergy. But only 1.9 percent of those given peanut protein three times a week developed a peanut allergy. In those children who initially had a mild allergy, 35 percent in the avoidance group developed a peanut allergy, compared to 10.6 percent in a mildly allergic group who ate a peanut protein.  

Introducing peanuts to baby 

This study clearly suggested that introducing peanuts to babies dramatically decreased the risk of developing a peanut allergy. So, in 2017 the National Institute of Allergy and Infectious Diseases came up with a set of guidelines for introducing peanuts to babies, which was endorsed by the American Academy of Pediatrics (AAP). Their recommendations are: 

  • Babies with a known egg allergy or severe eczema should be tested early for a peanut allergy. When they’re between 2 and 4 months old, speak to a pediatrician. Your physician may also request introducing peanuts in a medical office—as early as 4 to 6 months of age, says the AAP. 
  • Parents of babies with mild to moderate eczema should speak with a pediatrician first, but their children can generally try peanuts around 6 months old. 
  • Then there are babies with no eczema or existing food allergy—and who don’t have a raised risk for an allergy. Based on family preference and culture, they can be introduced to peanuts at any time after they’ve had a few other solid foods with no allergic reaction.

What you need to know 

What I tell my patients is this: Introducing peanut products to your baby starting at around age 6 months is a good idea, but you must be extremely careful. Do not give any child under 4 years old whole peanuts, as they can be a choking hazard. In terms of peanut butter, it may be difficult (and dangerous) for an infant or toddler to move a glob of peanut butter around his mouth and swallow.   

But older infants, around 8 or 9 months of age, may be able to handle a thin smear of creamy peanut butter to lick off of a parent’s finger or on a thin piece of soft bread. Alternatively, you could mix peanut butter into a pureed food (such as oatmeal) that you are already feeding your infant, or mix a small amount into muffins. Be sure to ask your pediatrician or pediatric allergist before introducing peanut products to your baby. 

While it’s difficult to know exactly how much to give your child (to replicate the amounts in the study), giving your child a taste is a good idea since peanuts are a healthy food.  

You may be wondering if you can cause your child to become allergic by introducing peanuts at a young age. The answer is no: The study results show that it can actually decrease the possibility. If your child should develop an allergy after this exposure, it would likely have happened anyway. 

And one final note: Allergic reactions can vary from mild—such as dry, itchy skin—to hives, facial or lip swelling or trouble breathing. If there is swelling or trouble breathing seek medical help immediately. 

Meanwhile, I’m mixing some peanut butter into my 6-month-old’s oatmeal. Yum! 

Article sources open article sources

FARE. “Facts and Statistics.” 2021. Accessed March 5, 2021. 
G DuToit, G Roberts, et al. “Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy.” New England Journal of Medicine. February 26, 2015. 372:803-813. 
Sarah DeWeerdt. “The peanut snack that triggered a fresh approach to allergy prevention.” Nature. December 2, 2020. Accessed March 5, 2021. 
Claire McCarthy. “Peanut Allergies: What You Should Know About the Latest Research & Guidelines.” American Academy of Pediatrics. January 17, 2020. 
Amanda Cox. “When can I start giving my baby peanut butter?” American Academy of Pediatrics. March 17, 2019. 
American Academy of Pediatrics. “AAP Clinical Report Highlights Early Introduction of Peanut-based Foods to Prevent Allergies.” March 18, 2019. Accessed March 5, 2021. 

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