Many people are unable to consume dairy products due to lactose intolerance, but some are unclear on exactly what this entails. Unlike a milk allergy, which involves an immune reaction to proteins in milk, lactose intolerance involves the interaction between lactose and lactase within the human body. Understanding the function and activity of both lactose and lactase can help you understand lactose intolerance and how the body digests milk and milk products.
Lactose
Lactose is the primary sugar found in milk. It occurs in the milk of all mammals, including cow's milk, goat's milk, sheep's milk and human breast milk. Dairy products such as yogurt, cheese and ice cream also contain lactose, although the levels are lower than in milk. Any product made with even small amounts of milk can contain lactose, including bread, processed foods, salad dressings and candies.
Lactase
The enzyme lactase is produced in cells lining the small intestines, called intestinal epithelial cells. The function of lactase is to break down lactose into two smaller sugars, glucose and galactose. Glucose and galactose can be absorbed into the bloodstream, while undigested lactose cannot. Most people produce lactase as infants unless they have a genetic disorder that prevents lactase production. Babies' bodies are primed to produce lactase in order to break down the lactose in breast milk. The production of lactase gradually decreases with age. The loss of lactase usually begins at about age two for people of African descent and around age five for Caucasians.
Lactose Intolerance
People with lactose intolerance either don't produce any lactase at all or produce too little to efficiently break down the lactose they ingest. It can also be called lactase deficiency. Although lactase production begins to slow in early childhood, symptoms of lactose intolerance, such as bloating and gas after consuming dairy, may not appear until adolescence or even adulthood. Most people with lactose intolerance have a mild version and are able to consume small amounts of dairy. Some people have severe lactose intolerance and cannot handle even the tiny amounts in processed foods made from milk.
Supplemental Lactase
Lactase enzyme is available as a dietary supplement for individuals with lactose intolerance. In some cases, the purified enzyme is added to milk or dairy products to produce lactose-free versions. This addition of lactase destroys the lactose in the milk before it is consumed. Lactase is also available in a tablet or suspended in liquid drops. Taking supplemental lactase before consuming dairy products may help the body digest the lactose.
Member Comments