After years of recommending that infants not be given peanut products, doctors and other medical experts officially reversed that guidance in 2017. Allergies to the legume have been dropping ever since.
A new study, published in November 2025 in the journal Pediatrics, found that food allergy rates in children under 3 fell dramatically after those guidelines were put in place, with a 36 percent reduction in all food allergies, largely driven by a 43 percent drop in peanut allergies.
Kristin Grunbaum, MSN, APRN, FNP-BC, says that’s exciting news, in part because once you have a peanut allergy, you rarely outgrow it. “A child can outgrow many other food allergies, but you’re usually stuck with a peanut allergy for life,” she says.
Grunbaum says, “A tipping point came in 2015 when research showed that the peanut allergy rate for children in the U.S. was higher than it was for children in Israel, where young children had peanut products added to their diets at an earlier age.
“Now the current national guidelines recommend introducing common food allergens to all infants between 4 and 6 months of age,” explains Grunbaum. “Early introduction to the nine commonly allergenic foods a couple of times a week – like a pea-sized smear of peanut butter – can help train an infant’s immune system.”
Grunbaum says that the link between eczema and peanut allergy is an important one. “Food allergies are more common in children with eczema. The worse the eczema is, the more likely the child is to have them.
“If your child’s eczema is severe, he or she should be tested before you introduce any peanut-based product into the diet to determine if the child has an allergy. Your pediatrician can do the test.”
Food allergies are reactions your body has to a food that it mistakenly thinks is harmful. In trying to protect you, it can cause hives, swelling, an upset stomach and difficulty breathing.
Dr. David Hill, a pediatric allergist at Children’s Hospital of Philadelphia, explains that when food allergens are introduced through the gut, it can build tolerance. He says, “For the past decade, studies have shown that introducing allergenic foods in infancy, as the immune system is developing, can help the body recognize food proteins as harmless.”
Grunbaum says the rate at which food allergies – mainly peanut allergies – had been increasing before the recent decline was amazing. “When I began practicing, if I saw a child with a food allergy once a month it was a lot. Now I routinely do skin tests on a child for up to 70 different foods,” she says.
Grunbaum says that while there may be multiple reasons for the increase, she believes a main one is that we over-sanitize our homes, which can interfere with a baby’s ability to develop a strong and healthy immune system.
This idea is the basis of “The Hygiene Hypothesis,” which suggests that the critical post-natal period of immune response is derailed by extremely clean household environments often found in the developed world. In other words, the young child’s environment can be “too clean” to pose an effective challenge to a maturing immune system.
According to the hygiene hypothesis, the problem with extremely clean environments is that they fail to provide the necessary exposure to germs required to “educate” the immune system so it can learn to launch its defense responses to infectious organisms. Instead, its defense responses end up being so inadequate that they contribute to the development of asthma and allergies (including food allergies).
At the same time, it’s possible to develop a peanut allergy later in your life. According to a 2021 study, approximately 17.5 percent of people with peanut allergies developed the allergy as adults, typically between the ages of 30 and 39.
Though the cause of adult-onset food allergies is not well understood, people with existing allergic conditions, such as eczema or asthma, insect sting allergies or latex allergies, are more likely to develop new allergies as adults.
Genetics may also play a role. If a family member has a peanut allergy, it could raise your risk of developing one later in life. It’s also possible that your peanut allergy was present in your childhood but not recognized or diagnosed until later in life.
Kristin H. Grunbaum, MSN, APRN, FNP-BC, has been specializing in allergy, asthma and immunology for more than 19 years. She has a B.S.N. from Florida State University and an M.S.N. from Florida Atlantic University. She practices in the office of Mark J. Pamer, DO, LLC, 573 NW Lake Whitney Place, #105, St. Lucie West.
