Study Finds Daily Peanut Exposure May Help Desensitise Adults with Severe Allergies

A new clinical trial has found that adults with severe peanut allergies may be desensitised through daily exposure to small amounts of peanut protein, offering a potential new treatment path for individuals who currently manage their condition through strict avoidance, the Guardian report.

Conducted by researchers at King’s College London, the trial is the first of its kind focused on adults and suggests that immunotherapy—already used in children—may also benefit older individuals. The study, known as the Grown Up Peanut Immunotherapy (GUPI) trial, included 21 adults between the ages of 18 and 40 who had a clinical diagnosis of peanut allergy.

Participants began with extremely small amounts of peanut flour, less than 1% of a whole peanut, and gradually increased their intake under medical supervision. Over several months, two-thirds of the participants reached a point where they could safely consume 1.4 grams of peanut protein—approximately five peanuts—without experiencing an allergic reaction.

“Although peanut immunotherapy is known to be effective in children, this trial provides preliminary evidence that adults can also be desensitised and that this improves quality of life,” said Professor Stephen Till, who led the research.

The approach, known as oral immunotherapy, involves regularly ingesting controlled amounts of an allergen to build tolerance over time. Participants in the trial eventually maintained a daily dose to remain desensitised. Despite this progress, researchers cautioned that the individuals remained allergic and should continue carrying emergency medication such as an adrenaline auto-injector.

The process took between 8 to 14 months for most participants, although pandemic-related delays extended the trial to nearly two years for some. Hannah Hunter, the trial’s lead author and an allergy dietitian at Guy’s and St Thomas’ NHS Foundation Trust, said many participants reported a significant reduction in anxiety related to accidental exposure.

While the trial’s findings are promising, researchers emphasize that larger, multi-center studies are needed before the treatment can be made widely available.

Professor Adam Fox, chair of the national allergy study group at King’s College London, noted that while oral immunotherapy is often considered most effective in children, the adult-focused trial indicates it can still offer meaningful benefits later in life.

The full findings of the study have been published in the journal Allergy.