Lactose Intolerance

Lactose intolerance is the inability to digest significant amounts of lactose, the predominate sugar in milk. This inability results from a shortage of the enzyme lactase, which is normally produced by the cells that line the small intestine. Lactase breaks down milk sugar into simpler forms that can then be absorbed into the bloodstream. While not all people deficient in lactase have symptoms, those who do are considered to be lactose intolerant. Common symptoms of lactose intolerance are: nausea, cramps, bloating, gas, diarrhea, which begin about thirty minutes to two hours after eating or drinking foods containing lactose. The severity of symptoms varies depending on the amount of lactose each individual can tolerate.

Some causes of lactose intolerance are well known. For instance certain digestive diseases and injuries to the small intestine can reduce the amount of enzymes produced. In rare cases, children are born without the ability to produce lactase. For most people, lactase deficiency is a condition that develops naturally over time. Certain ethnic and racial populations are more widely affected than others. As many as seventy-five percent of all African Americans and American Indians and ninety percent of Asian Americans are lactose intolerant. The condition is least common among people of northern European descent.

Fortunately, lactose intolerance is relatively easy to treat. No treatment can improve the body's ability to produce lactase, but symptoms can be controlled through diet. Young children with lactase deficiency should not eat any foods containing lactose. Most older children and adults don't have to avoid lactose completely, but people differ in the amounts and types of food they can handle. For those who react to very small amounts of lactose or have trouble limiting their intake of foods that contain it, lactase enzymes are available without a prescription to help people digest foods that contain lactose. A carefully chosen diet, with calcium supplements if the doctor or dietitian recommends them, is the key to reducing symptoms and protecting future health.