Food allergy is a form of adverse reaction to food in which the cause is an immunological response to a food. Common food triggers are eggs, cow's milk, peanuts and fish. Food allergy is mot common in young infants, most of whom grow out of the allergy by the age of 5 years. The exception is allergy to peanuts, which is life-long. The term food intolerance does not imply any specific type of mechanism, and is defined as a reproducible adverse reaction to a specific food or food ingredient. Mechanisms for food intolerance comprise immunological reactions (i.e. food allergy), enzyme defects, pharmacological effects, irritant effects, and toxic reactions. Despite the popular phobia of food additives and food processing, and the obsession for so-called natural foods, the greatest dangers come from naturally occurring foods and food ingredients.