A British study provides some of the strongest evidence yet that feeding small amounts of peanut flour to children and teens with peanut allergies can help desensitize them to the nuts.
But the approach remains experimental and much too dangerous for anyone to try without medical supervision, experts say.
For the study, published Thursday in the journal Lancet, researchers divided 99 children into two groups who took turns undergoing the therapy. The patients ate increasing - but small - amounts of the peanut flour under the watchful eyes of doctors.
In both six-month rounds of therapy, more than half of the treated participants ended up able to eat the equivalent of 10 peanuts at a time. More than 80% could eat the equivalent of five peanuts. The initially untreated children showed no such improvement after the first round.
Some of the treated children did get upset stomachs and one child ended up having an allergic reaction severe enough to require an injection of epinephrine.
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The results are "exceptionally promising," but the treatment remains years away from routine use, says an editorial accompanying the study, written by Matthew Greenhawt, a pediatric allergist at the University of Michigan. He also notes that studies have yet to show if patients can develop long-lasting tolerance.
U.S. researchers also are studying the approach - known as oral immunotherapy - for peanuts, walnuts and other allergens, says the non-profit group Food Allergy Research & Education.
For now, the group says, the only proven treatment for peanut allergies is avoidance.
Allergies to peanuts and tree nuts affect 1.4% of U.S. children and rates have been rising, surveys find. Nut allergies are the leading cause of fatal allergic reactions.