Lactose (also: lactose) is a type of sugar found in the milk of all mammals. It is of great importance in the diet of infants and is broken down in the body with the help of the enzyme lactase. When there is a deficiency of lactase, which can occur after early childhood, severe digestive disorders occur when lactose is ingested in milk or dairy products.
What is lactose?
The term lactose is derived from “lac,” the Latin word for milk, and refers to a sugar naturally present in milk. It is a two-sugar that is broken down into the single sugars galactose and glucose during the digestive process by the body’s enzyme lactase. Because of comparatively poor water solubility, the colorless lactose in milk is present in crystalline form.
Medical and health functions, roles, and meanings.
Lactose is one of the major components of milk and, as such, is essential for feeding the young of all mammalian species. As a type of sugar, it provides the body with energy quickly and also stimulates the appetite due to its sweet taste. At the same time, it promotes the absorption of calcium and thus bone growth. In addition, lactose supports the formation of healthy flora in the intestines of infants by inhibiting the proliferation of putrefactive bacteria and at the same time promoting the colonization of healthy bifidus cultures. In larger quantities, however, lactose has a laxative effect. In order to digest lactose, the enzyme lactase is required. This breaks down the double sugar into the single sugars galactose and glucose, which can then be absorbed by the small intestine. During the breastfeeding period, the body of healthy infants always produces this enzyme in sufficient quantities so that the absorption of lactose does not lead to any digestive problems. With weaning, lactase production can be reduced to as little as five percent of the original amount. As a result, the body can no longer utilize the lactose supplied with food.
Diseases, complaints and disorders
When lactose cannot be properly digested because of a lactase deficiency, it manifests itself with a variety of disease symptoms. Because the lactose contained in dairy products and many other industrially produced foods is not already broken down into simple sugars in the upper part of the digestive organs, it reaches the large intestine unchanged. There it is fermented by intestinal bacteria, which can lead to severe flatulence and diarrhea. Abdominal cramps, nausea and vomiting are also common symptoms of lactose intolerance. Less commonly, non-specific symptoms may include sleep disturbances, chronic fatigue, depression, difficulty concentrating, and headaches and aching limbs. However, the inability to digest lactose is not a disease in the true sense of the word, but is actually the normal state of affairs worldwide. In many countries in Africa and Asia, more than 90 percent of people over the age of infancy do not have the ability to produce lactase and thus break down lactose. The formation of the enzyme necessary for lactose digestion well into adulthood is actually the result of a mutation that is relatively recent in human evolutionary history. Being able to digest lactose offered a decisive advantage with the advent of animal husbandry, so that today this trait is found primarily in the descendants of corresponding cultures. This is particularly true for the inhabitants of Europe and countries settled by Europeans, as well as for some peoples of northern Asia and Africa. Nevertheless, an estimated 20 percent of people in Germany suffer from natural lactose intolerance. In addition, there are still various diseases that can inhibit or permanently disrupt the digestion of lactose. These include in particular various diseases of the gastrointestinal tract, such as gastroenteritis, celiac disease, infestation with giardia, duodenal diverticulum, short bowel syndrome or intestinal lymphoma. Malnutrition or chronic abuse of alcohol can also significantly limit the ability to digest lactose. Surgical removal of parts of the intestine, as well as chemotherapy and radiotherapy associated with cancer treatment, also affect the digestion of lactose.
