Lactose intolerance and milk consumption

The disaccharide lactose is one of the main components of milk. During the digestion, it is hydrolysed by the enzyme ß-galactosidase into glucose and galactose. With the exception of the Caucasian populations the lactase activity decreases in most people in the age of weaning. After the ingestion of large amounts of lactose, symptoms as bloating, flatulence, abdominal pain and diarrhea can occur due to the lactose reaching the large intestine. This phenomenon is called lactose intolerance or lactose maldigestion. But also in Caucasian populations there are some people who suffer from it. In the past, such populations have used this phenomenon, after weaning, to discourage the consumption of milk. However, nowadays it is recognised that lactose maldigesters can tolerate one cup of milk or two cups of milk a day, when taken over the day with meals. They can also consume cheese that contains no or only small amounts of lactose. Studies performed during the last 15 years have shown that yogurt is very well tolerated by lactose maldigesters. This is attributed to the presence of living lactic acid bacteria in fermented dairy products and to the lactase present in these products.