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What Is Lactose Intolerance?

Lactose intolerance occurs when the body cannot easily digest lactose, a type of natural sugar found in milk and dairy products.

Lactose is present in almost all dairy products and is normally digested in the small intestine with the help of an enzyme called lactase which splits the disaccharide into two monosaccharides (simple sugars).

Without this enzyme, or enough of this enzyme, the body does not break down all the lactose into smaller parts for digestion and absorption and as a consequence reaches the large intestine. Here there are bacteria that process the lactase and this leads to the production of various gases. When lactose moves through the large intestine (colon) without being properly digested, it can cause uncomfortable symptoms such as gas, belly pain, and bloating.

In principle all mammals have the ability to digest lactose. However, in all mammals the ability to digest lactose decreases or disappears as they get older since there is no reason, from a biological perspective, for a fully grown mammal to drink milk that is intended for babies.

Lactose intolerance is common in adults. It occurs more often in Native Americans and people of Asian, African, and South American descent than among people of European descent. Some people who have lactose intolerance cannot digest any milk products. Others can eat or drink small amounts of milk products or certain types of milk products without problems.

There are three different types of lactose intolerance

Primary lactose intolerance

  This is the most common form of lactose intolerance. Its cause is genetic and it occurs more frequently in warmer and sunny regions 

Secondary lactose intolerance

:In this case there is no genetic defect, but it is caused by a disorder in the intestinal mucosa.

Congenital lactose intolerance

This is an autosomal recessive genetic defect where not even the smallest amount of lactase is produced.. This type of lactose intolerance is very rare and it already affects newborn babies. 

This information has been sourced, in part from the following sources: Net Doctor UK  Dietitians of Canada  Food Intolerence Network  Web MD