Food Allergies and Intolerances-Post 2
Food intolerance is similar to food allergy in that it produces an unpleasant reaction to food. Unlike food allergies, which involve an immune system response, food intolerances are usually caused by a deficiency or a reaction in the digestive system. Food intolerances can occur shortly after ingesting the problematic food or days later, making it hard to pinpoint the cause of the reaction. Typical intolerance symptoms include nausea, bloating, flatulence and diarrhea. Two common food intolerances are lactose intolerance, caused by a deficiency in the enzyme (lactase) needed to break down the sugar in milk (lactose); and celiac disease, a reaction to the consumption of gluten (found mainly in wheat, rye and barley) that damages the small intestine and results in poor absorption of nutrients.