It may sound radical, but it works: Eating peanuts slashes the chance of a peanut allergy, at least in children at high risk of developing one, a much-anticipated study finds. The results are likely to catapult a long-standing theory—that ingesting potential food allergens is a way to prevent allergies—into mainstream medicine.
“This is the study,” says Rebecca Gruchalla, a specialist in allergy immunology at the University of Texas Southwestern Medical Center in Dallas, who wasn’t involved in it. The data, she says, are “just mind-blowing.”
The trial, the results of which are published today in The New England Journal of Medicine to coincide with their presentation at a major allergy meeting in Houston, Texas, is by far the largest and longest running of its kind, with 640 children followed over 4 years. It was launched back in 2006, when both the United States and United Kingdom recommended that parents keep peanut products away from high-risk youngsters until they turned 3, advice families in other Western countries often followed, too. But as these children eschewed peanut butter, doctors were increasingly uncertain whether their recommendations were sound. Peanut allergies, which can be fatal, were soaring in the same countries that urged avoidance: In the United States, the prevalence of peanut allergy more than tripled between 1997 and 2008, to 1.4%. In Israel, meanwhile, where the environment is not appreciably different from other industrialized countries, only about 0.17% of schoolchildren were allergic. What was different there? For one, many Israeli babies consume a wildly popular snack of peanut puffs called Bamba by the time they’re 6 months old.
The rationale for avoidance was simple: It’s not possible to become allergic to a food unless exposed to it, and doctors had believed that the guts and immune systems of older children may be better able to tolerate potential allergens, making the body less likely to react badly to new foods. But...