True food allergies are overreactions of the body’s immune system, which mistakes a food component as a sign of invasion by a bacterium or virus and initiates a defense that damages the body. The damage may be mild and manifest itself as discomfort, itchiness, or a rash, or it may be a life-threatening asthma or change in blood pressure or heart rhythm. It’s estimated that about 2% of adults in the United States have one or more food allergies, and up to 8% of young children. Allergic reactions to food cause around 200 deaths per year in the United States. Peanuts, soybeans, and tree nuts are among the most common food allergens. The offending components are usually seed proteins, and cooking does not render them less allergenic. Tiny quantities of nut proteins are sufficient to cause reactions, including the levels sometimes found in mechanically extracted nut oils.