Food intolerance

Abstract

Food intolerant symptoms can have various causes, including enzyme deficiencies (of lactase or aldehyde dehydrogenase) and pharmacological effects (e.g., caffeine, salicylates). The irritable bowel syndrome can also be associated with intolerance to specific foods in some cases, but the mechanism is unclear. Immunological causes are less common but may explain the small bowel mucosal changes associated with gluten enteropathy, as well as the childhood enteropathy provoked by cow's milk or, rarely, by other foods. Food allergy of the more immediate and classical type is associated with reactions both within and outside the gastrointestinal tract. Where these include urticaria, asthma and eczema, immunoglobulin E antibodies are often demonstrable by skin or radioallergosorbent tests, but pseudo-allergic reactions can produce a similar clinical picture. Diagnosis of food intolerance depends on withdrawing the food concerned and assessing the response to a blind challenge. Objective ways of detecting subclinical reactions are also useful, including the detection of a mediator response involving prostaglandins, histamine or serotonin.