Lactose maldigestion is a common health condition, with symptoms that may include mild to severe abdominal discomfort. People who are lactose maldigesters or are lactose intolerant have difficulty digesting lactose, the sugar found in milk and milk products. Although all infants are born with the ability to digest milk properly, this ability declines with age in many people; lactose maldigestion is particularly prevalent among certain ethnic groups, including Native Americans, Asians and African-Americans.
Without sufficient amounts of the enzyme lactase, necessary for breaking down milk sugars in the digestive system, undigested lactose enters the large intestine. There, it becomes fermented by the colon’s bacteria, producing the gases methane, hydrogen and carbon dioxide, which can lead to abdominal discomfort.
Symptoms occur 30 minutes to two hours after eating or drinking milk or milk products, and can include belching, gas, bloating, cramping and diarrhea. Steve Hertzler, professor of human nutrition at Iowa State University, notes that lactose maldigestion occurs on a continuum, with some more sensitive than others. A person who suffers from lactose maldigestion has difficulty digesting milk to some degree, but may exhibit few or no symptoms, whereas a person with lactose intolerance suffers gastrointestinal distress after drinking milk.
The symptoms of lactose maldigestion and lactose intolerance can resemble those of other conditions such as irritable bowel syndrome. Doctors must rely on tests that measure the digestion of lactose to make a definitive diagnosis. In the hydrogen breath test, a person first drinks a beverage containing lactose. His breath is then measured for the hydrogen produced by undigested lactose. A second test, used for infants and young children, measures the amount of acid in the stool.
Foods to Avoid
Depending on the degree of your lactose maldigestion, you may need to avoid milk and milk products, such as cream, ice cream, whipping cream and evaporated and condensed milk. You may also need to limit consumption of food prepared with milk, such as pudding, cream sauces or chowders.
Lactose-free milk -- milk to which lactase enzyme has been added -- is readily available in grocery stores and can substitute for regular milk cup for cup. It contains the same amount of calcium and other nutrients as regular milk. Cultured yogurt, another excellent source of calcium, may be well-tolerated by lactose-intolerant individuals, since the cultures convert lactose to lactic acid, aiding digestion, according to the National Digestive Diseases Information Clearinghouse. Be sure to choose yogurt that contains active and live bacterial cultures.