Many children with peanut allergies who were fed small but escalating amounts of peanut flour were eventually able to eat a significant quantity of peanuts with no reaction, a new study has found.

Six months after the treatment started, more than 80% of the children in the trial could safely eat the equivalent of five peanuts a day. That is at least 25 times the quantity of peanut protein that they could tolerate before the therapy.

"We found that in the treatment group, there was a substantial improvement in quality of life," said Andrew Clark, a specialist in pediatric allergies at Cambridge University Hospitals in the U.K. and leader of the study that was published Thursday in the journal Lancet. Dr. Clark noted that the study participants no longer had to scrutinize food labels or suffer allergic reactions during visits to restaurants.

"This is a fantastic study, and it has the best results to date," said Matthew Greenhawt from the University of Michigan Food Allergy Center, who wasn't involved in the research. It had more participants than previous studies—and the data showed fewer serious side effects in the children who enrolled.

Nonetheless, said Dr. Greenhawt, "as great as these results are, we're still at the very early stages" of trying to make the therapy ready for clinical use. The Lancet findings must be validated in larger studies and shown to be long-lasting. Scientists also need to understand how the treatment works biologically.

Peanut allergy, which affects 0.5% to 1.4% of children in high-income countries, is the most common cause of severe and fatal allergic reactions related to food. The only way around the problem is to avoid eating foods containing peanuts. Even then, many people suffer accidental reactions.

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