Can the cure for peanut allergies be… peanuts? Dr. Pamela Ewan discusses a new study she co-authored in which children with allergies were able to safely eat more peanuts prior to treatment. Photo: Associated Press

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.

The treatment reported in Lancet is known as immunotherapy, which has a lasting protective effect when used against grass pollen and wasp-sting allergies.

The Lancet study included 99 children, ages 7 to 16, with varying severity of peanut allergy. Half were randomly assigned to a treatment group. For 26 weeks, they received gradually escalating doses of peanut protein up to 800 milligrams a day. The other half in a control group avoided peanuts.

About a fifth of the children in the treatment group suffered side effects, but most of them were mild, with oral itching being the most common. But significantly, after six months of therapy, 62% of the participants in the treatment group could tolerate a daily dose equivalent to 10 peanuts. No one in the control group could tolerate any significant amount of peanut protein.

"As kids take an increasing amount, their immune systems start to change," said Dr. Clark. "They can tolerate peanuts more robustly."

There are indications that the immunotherapy approach may have lasting effects. A small group of study participants have been able to tolerate the treatment for at least four years, said Dr. Clark. Participants who reduced their intake from five peanuts a day to five a week could tolerate them. However, that data has yet to be published.

Write to Gautam Naik at