THE CLINICAL-SIGNIFICANCE OF DISACCHARIDE MALDIGESTION

The prevalence of lactose maldigestion is lowest in Scandinavia and Northwest Europe (3-8%) and close to 100% in most of Southeast Asia. In Europe the frequency increases in the southern and eastern directions, reaching 70% in southern Italy and Turkey. There is also a high prevalence of lactose maldigestion in the people of Africa with the exception of cattle-raising nomads. Lactose maldigestion causes uncharacteristic abdominal symptoms such as bloating, borborygmus, colic, flatulence, and diarrhea. The degree of discomfort depends on the amount of lactose consumed, but also on an individual sensitivity to lactose. The symptoms of irritable bowel syndrome (IBS) and lactose maldigestion are similar. Consequently, most investigations indicate an increased frequency of lactose maldigestion in patients suffering from IBS. Recurrent abdominal pain (RAP) in children corresponds to IBS in adults. Lactose maldigestion is a frequent cause of RAP in regions with a high prevalence of lactose maldigestion in early childhood. Diffuse small-intestinal damage in celiac disease or kwashiorkor leads to a proportional decrease of all disaccharidase activities, with the most pronounced being decrease of lactase. The consumption of milk may then cause abdominal discomfort and increased diarrhea. Several investigations have indicated an increased frequency of lactose maldigestion in patients with osteoporosis. A connection between lactose maldigestion and decreased absorption of calcium has not been proven, however. The increased tendency toward osteoporosis is more likely caused by a lower calcium intake because of milk intolerance. Milk and dairy products with reduced lactose content are better tolerated by patients with lactose maldigestion. Lactose-reduced milk can be produced by adding lactase to the milk, either before consumption or as an additive to be consumed with meals. Among dairy products, unpasteurized yogurt is best tolerated because of the action of its bacteria and lactase in the small intestine. In addition to a high incidence of lactose maldigestion (60%), sucrose maldigestion is also common (5%) among the Inuits in Greenland.