Peanut allergies can cause severe and sometimes deadly allergic reactions. A new study holds out the possibility that peanuts themselves may prevent peanut allergies. An international team asked parents of infants who were prone to a peanut allergy to give their children a peanut-based snack called Bamba or peanut butter three times a week until age five. The parents of another group of peanut allergy-prone infants were asked to make sure their children didn’t eat any peanuts, peanut butter, or other peanut-based products until age five. The results were surprising and dramatic. A peanut allergy developed in 1.9% of children who ate Bamba or peanut butter, compared with 13.7% of those who didn’t eat peanuts. This new work suggests that preventing peanut allergies may be a possibility in the near future.