Feeding peanut products to infants was connected with a 43 percent lower association with developing peanut allergies, according to a study published recently in the journal Pediatrics.
Researchers analyzed medical records of about 120,000 children younger than 3, comparing cohorts of children before and after varying guidelines and recommendations that shifted.
The findings come nearly a decade after guidelines began encouraging parents and caregivers to introduce peanut-containing foods earlier in babies' diets.
For decades, medical experts had recommended waiting until children were 3 years old to introduce peanuts. But that started to shift after the 2015 Learning Early About Peanut Allergy study, which showed that letting children as young as 4 months try peanuts earlier reduced the risk of developing allergies.
"This monumental public health effort in food allergies appears to be having an effect," said David Hill, an attending allergist at the Children's Hospital of Philadelphia and senior author of the study. "For every 300 children with food allergies, at least one is being spared from developing a peanut allergy."
About 5.8 percent of children in the United States had a food allergy according to 2021 data from the Centers for Disease Control and Prevention.
And although this recent study is encouraging, Hill said, he does not want parents of children with food allergies -- whether they introduced allergens early or not -- to feel "left behind"; many experts have said allergens and their causes still warrant further investigation.
When and how should I introduce peanuts to my children?
The National Institute of Allergy and Infectious Diseases advises parents to start with a diluted and small amount of peanut-containing food, then wait 10 minutes to watch for an allergic reaction. (Some medical providers recommend options such as peanut butter thinned with breast milk or formula or pureed into a food your child already eats, or a puffed corn snack made with peanuts called Bamba.)
Pediatricians also say infants should be meeting developmental milestones before the introduction of an allergen, including being able to hold their head up and having good oral motor control.
"If they're developmentally ready, that's the time to start introducing allergenic foods like peanuts," said Zachary Rubin, a pediatric allergist in the western suburbs of Chicago.
Babies with eczema have a higher risk of developing a food allergy, so some may benefit from earlier introduction under the guidance of a pediatrician.
"The way I like to describe it to families is that the immune system is plasticky early on, and then it hardens," said Rubin. "If you have a baby that's at risk of developing a food allergy, and you intervene earlier, you may be able to prevent the food allergy from developing, but it's not 100 percent."
Experts say that when a child has food allergies, there is not only a physical toll but a mental one. Studies have found that children with food allergies are more likely to have anxiety and reduced quality of life compared with their peers who do not have allergies.
"Children can't be carefree, and for parents it's very stressful because allergies influence where families can go: from restaurants to sporting events to social activities," said Ruchi Gupta, director of the Center for Food Allergy and Asthma Research at Northwestern University, who also serves on the board of the American Academy of Pediatrics Section on Allergy and Immunology.
What symptoms indicate an allergic reaction?
Most infants will not have a reaction the first time they try peanut products or any other allergens, experts say.
The most common symptoms are hives, redness or a rash that appears within minutes of eating the product. Some babies may vomit or appear uncomfortable. A mild reaction often involves a few scattered hives or mild stomach pain that resolves quickly.
Severe reactions are less common but require immediate attention. Parents should call 911 if a child has trouble breathing, persistent coughing or swelling of the tongue, or if the infant turns pale or blue.
"If you're scared and you feel like you can't manage it at home, don't hesitate to call," said Sara Anvari, director of clinical trials and translational research in the Food Allergy Program at Texas Children's Hospital in Houston.
For mild symptoms, an antihistamine such as diphenhydramine or cetirizine -- commonly known by the brand names Benadryl and Zyrtec -- may help relieve hives or itching, but parents should consult with their pediatricians.
And if more than one part of the body is affected, such as the skin and the respiratory or gastrointestinal system, doctors consider it a severe reaction and recommend using epinephrine if available and seeking out emergency care.