Food allergy articles
Article pagesThe difference between an allergy and an intolerance is how the body handles the offending food. In a true food allergy, the body's immune system recognizes a reaction-provoking substance, or allergen, in the food--usually a protein--as foreign and produces antibodies to halt the "invasion." As the battle rages, symptoms appear throughout the body. The most common sites are the mouth (swelling of the lips), digestive tract (stomach cramps, vomiting, diarrhea), skin (hives, rashes or eczema), and the airways (wheezing or breathing problems). People with allergies must avoid the offending foods altogether.
Cow's milk, eggs, wheat, and soy are the most common sources of food allergies in children. Allergists believe that infant allergies are the result of immunologic immaturity and, to some extent, intestinal immaturity. Children sometimes outgrow the allergies they had as infants, but an early peanut allergy may be lifelong. Adults are usually most affected by tree nuts, fish, shellfish, and peanuts.
Food intolerance is a much more common problem than allergy. Here, the problem is not with the body's immune system, but, rather, with its metabolism. The body cannot adequately digest a portion of the offending food, usually because of some chemical deficiency. For example, persons who have difficulty digesting milk (lactose intolerance) often are deficient in the intestinal enzyme lactase, which is needed to digest milk sugar (lactose). The deficiency can cause cramps and diarrhea if milk is consumed. Estimates are that about 80 percent of African-Americans have lactose intolerance, as do many people of Mediterranean or Hispanic origin. It is quite different from the true allergic reaction some have to the proteins in milk. Unlike allergies, intolerances generally intensify with age.
