What is lactose?

Lactose is the so-called milk sugar and is found in the milk of mammals. The proportion of milk sugar in milk can vary between 2% and 7%. Lactose is a so-called dual sugar, which consists of two different types of sugar.

As a sugar, lactose belongs to the group of carbohydrates and is therefore an energy supplier for the body. In order to be able to utilize lactose, it must first be broken down into the individual sugar molecules after absorption. This is done by the enzyme lactase.

The individual components can then be absorbed into the blood by the intestines and transported to the organs. In infancy, high amounts of lactase are found in the body, as a lot of milk sugar has to be broken down from breast milk. In adulthood, however, lactase is only formed in small quantities as milk consumption decreases.

If the milk sugar can no longer be broken down and absorbed, this is called lactose intolerance. Lactose is not only found in milk, but also in all dairy products, such as yoghurt, buttermilk and cheese. However, the amount of lactose varies. In cream cheese it is more than 2%, whereas hard cheese has a lactose content of less than 0.1%. Even lactose-free products may contain a small amount of lactose.

Lactose intolerance

Lactose intolerance is also known as lactose intolerance. In Germany about one in seven people suffer from it. The reason for this is that the enzyme lactase is not present or only in insufficient quantities.

The lactose ingested with food can therefore not or not completely be broken down into its individual components and as a result cannot be absorbed into the blood by the cells of the intestinal mucosa. The lactose thus remains in the intestine and is digested by bacteria. The bacteria produce gases and acids which can lead to digestive problems.

This is why lactose intolerance often leads to flatulence after eating products containing lactose. In addition, the lactose that remains in the intestine draws water into the bowel and leads to diarrhoea. Often the enzyme lactase is still sufficiently present in childhood, but in advanced age a deficiency and a resulting lactose intolerance occur.

It is noticeable that lactose intolerance occurs with varying frequency in different countries. This is probably due to both genetic causes and dietary habits. Very rarely, lactose intolerance is congenital and already leads to symptoms in infants.