New clinical trial finds that adults can outgrow peanut allergies

In a world where a trace of peanut could send some adults to the emergency room, a major breakthrough is offering new hope. A new study has shown that oral immunotherapy—a treatment already helping children—can also work for adults with severe peanut allergies. For the first time, a clinical trial has proved that many adults can build tolerance to peanuts through carefully monitored exposure, changing their lives in powerful ways.

This study, known as the Grown Up Peanut Immunotherapy (GUPI) trial, followed a group of adults who had long lived in fear of accidental exposure. For these participants, the smallest trace of peanut could lead to a medical emergency. But the results of this groundbreaking research offer more than just medical data—they offer peace of mind and a better life.

Peanut oral immunotherapy (OIT) involves eating small amounts of peanut in a controlled and increasing manner. This helps the immune system slowly get used to peanuts, reducing the chance of a serious reaction. While past studies showed strong success in children, this was the first to test the method in an adult-only group.

The GUPI trial involved 21 adults between ages 18 and 40. These volunteers had confirmed peanut allergies diagnosed through a skin prick test, a blood test, and an oral food challenge at Guy’s and St Thomas’ NHS Foundation Trust. Each person had a long history of avoiding peanuts to stay alive.

The trial began with extremely small doses of peanut flour, starting at just 0.8 milligrams—less than one percent of a single peanut. These tiny doses were mixed with food and taken under strict medical supervision. Over time, the doses increased. Participants moved up to 6 milligrams, then gradually to 1 gram—the amount found in about four peanuts.

Once a participant could handle 1 gram daily, they stayed at that level for at least four weeks. Then came the real test: a double-blind, placebo-controlled food challenge. This step measured whether they could safely eat peanuts or if their allergy would still kick in. The participants continued with daily peanut exposure for at least three more months after the challenge.

By the end of the trial, 67% of participants—two-thirds of the group—could safely eat at least 1.4 grams of peanut protein, about five peanuts. This level of desensitization meant they no longer needed to panic about small, accidental exposures.

Professor Stephen Till, who led the study at King’s College London, shared his thoughts on the results. “Constant fear of life-threatening reactions places a huge burden on people with peanut allergy,” he said. “Although peanut immunotherapy is known to be effective in children, this trial provides preliminary evidence that adults can also be desensitized and that this improves quality of life. The average tolerated dose of peanuts increased 100-fold over the course of the trial.”

That means participants went from reacting to less than one percent of a peanut to safely eating several whole ones. They continued to eat peanuts daily to stay desensitized, often using peanut butter or whole peanuts as part of their routine.

For many, the impact of the treatment went beyond numbers and tests. It reached deep into their daily lives, affecting the way they traveled, socialized, and made career decisions.

Allergy dietitian Hannah Hunter, the lead author of the study, explained: “Living with peanut allergy is a huge burden due to the need for constant vigilance and the risk of accidental exposures. Everyday situations such as eating in restaurants and social events are anxiety-provoking, and our patients tell us that the condition also affects travel choices and career options.” She also noted that "quality of life significantly improved after oral immunotherapy and fear of food also decreased."

“I’m so proud to have been part of this trial and so happy to say that I used to be allergic to peanuts but thanks to this trial, this is no longer a concern,” said Chris Brookes Smith, one of the participants. “Me and my family were always anxious that even a trace of peanut could be life-threatening.”

For Chris, the trial changed his relationship with food. “All of my life I had associated the taste and smell of peanuts with fear and death,” he said. “I started with a small amount of peanut flour with yoghurt, and by the end of the trial I could eat four peanuts in one sitting.” He now eats four peanuts with breakfast every day to stay immune. “Before, a tiny mistake could have life-threatening impacts, but now I don’t have the fear that I might collapse and die from eating a takeaway,” he said.

The study’s success is only the beginning. While the trial included just 21 people, its results open the door to future research with larger groups. The hope is to confirm these findings, understand how many adults could benefit, and figure out whether the effects can last long-term without continued daily peanut intake.

Professor Till explained that this small study offers important insights but more work lies ahead. “The next stage of the research will be confirming this in larger trials,” he said, “and also identifying the group of adult patients who would most likely benefit from oral immunotherapy, and see whether it can lead to long-term tolerance in this age group.”

So far, peanut oral immunotherapy has been viewed mostly as a tool for treating children. But this study shows that adults, too, can build up their tolerance and move past the fear that has shaped so much of their lives.

Thanks to the GUPI trial, many adults now have proof that the allergy they believed would always limit them might not be so permanent after all. With further research, the idea of a life without fear of peanuts may become a reality for many more.

Research findings are available online in the journal Allergy.

Note: The article above provided above by The Brighter Side of News.

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