The human digestive system produces special enzymes to break down lactose.
Lactose is a sugar component in all dairy products. Almost 40 grams of lactose is in every liter of milk. The human body might have difficulty digesting this sugar, making some people lactose intolerant.
How
The human body produces lactase, an enzyme in the small intestine, which can break down lactose. Babies produce large amounts of lactase to digest their mother's milk. However, as a person ages, especially after the age of 2, lactase levels drop. Only when a person continues drinking and consuming dairy products does lactase levels remain constant.
Purpose
Lactose is a complex sugar, made up of glucose and galactose. Those two sugars are easier to digest than lactose itself. Efficient lactase production breaks the lactose down into sugars, allowing simple absorption into the bloodstream through the small intestine.
Considerations
Genetic or outside forces cause a reduction in lactase. People may be inherently intolerant to lactose because lactase is not produced enough, if at all, in the person's small intestine. This reason may be genetic, even if the child consumes dairy past the age of 2. Digestive conditions such as Crohn's disease or medical treatments like chemotherapy may also hinder lactase production.
Tags: small intestine, break down, break down lactose, dairy products, down lactose, human body, lactase levels