Early and gradual exposure to peanuts under medical supervision curbed infants' allergies, according to a new study.

While researchers had seen that peanut oral immunotherapy was well tolerated by toddlers, this research focused on an even younger age group.

"We've seen how peanut oral immunotherapy is well-tolerated in toddlers, but there is limited real-world evidence available to demonstrate the benefits in babies," said Dr. Sandra Hong, director of the Food Allergy Center of Excellence at the Cleveland Clinic. "We leveraged data from infants in our program to better understand the safety and efficacy of this treatment in children 12 months and younger."

The clinic's Food Allergy Center of Excellence offers oral immunotherapy for babies, toddlers and young children who are allergic to peanuts. There, children under age 4 eat tiny amounts of peanuts in a step-by-step, controlled process.

This study enrolled 22 infants between 7 and 11 months old. With an allergist and parent, the babies started on a daily dose of 18 milligrams of peanut protein in the form of peanut butter or peanut powder. That's roughly twice the weight of a grain of table salt.

Over six months, they were slowly given larger servings to consume until they reached a maintenance dose of 500 milligrams, the equivalent of two peanut kernels.

Each of the 22 babies reached this milestone. More than half experienced mild allergic reactions during treatment that resolved on their own. One required epinephrine. About 27% of the babies had no allergic reactions.

"Safety is paramount. Each time babies were exposed to a larger amount of peanut protein, it was done under the careful supervision of an allergist," Hong said in a clinic news release. "They were monitored for an hour in our office after the higher dose was given."

After finishing immunotherapy, 14 of the 22 babies received an allergy test to check levels of peanut-specific antibodies. All 14 had a reduced sensitivity to peanuts.

After that, 11 of those babies participated in an oral food challenge where they were fed increasing doses of peanut protein up to 2,000 milligrams, (about nine peanuts). In all, 91% of them could tolerate peanuts without triggering any allergic reactions.

"Our study shows that the majority of babies were able to safely consume peanuts after oral immunotherapy," said lead author Dr. Sarah Johnson, a fellow at the Cleveland Clinic.

"Overall, this signals that age is a crucial factor to the success of this treatment," she said in the release. "An infant's immune system is more adaptable, allowing them to develop tolerance to peanuts with less severe reactions and fewer side effects than older children."

About 1.5 million U.S. children have a peanut allergy. Fewer than one-third develop tolerance for peanuts naturally.

This treatment should always be done under the care of a trained allergist, researchers stressed.

"At the end of the day, we want families to be safe," Hong said. "This is not something you try on your own because of the significant risk of triggering allergic reactions. When you have an allergist supervise the process, you are ensuring that any reactions your child experiences are quickly identified and treated."

Study findings were recently published in the Journal of Allergy & Clinical Immunology: In Practice.