Peanuts are one of the biggest triggers of food allergies, but the nuts themselves may not be causing the negative reactions. Researchers at Oxford University and University of Pennsylvania have discovered that the dry-roasting process may be what elicits many of the allergic reactions to peanuts. Experiments on mice exposed to dry-roasted peanuts showed they had a stronger immune reaction to both raw and dry-roasted peanuts than mice exposed just to raw peanuts. This evidence suggests that the dry-roasting process alters “physiochemical properties of peanut proteins,” the study’s authors wrote in their study published in the Journal of Allergy and Clinical Immunology. If dry-roasting turns out to be responsible for peanut allergies, it could explain why peanut allergies are so much more common in North America and Europe than East Asia, where dry roasting is used less frequently.