Lactose is present in milk and its derivatives. Lactose intolerance is due to a decrease in the enzyme needed for its metabolism and absorption in the walls of the intestine.. This enzyme is called lactase.
The frequency of lactose intolerance is detected differently in different countries. The areas most used to consume milk suffer less cases of lactose intolerance. In Scandinavians and Anglo-Saxons it is approximately 5%, in Spaniards 15-30%, and in Central Africa or China more than 80%.
Lactose intolerance can be permanent (congenital) or temporary (acquired). The permanent form is genetically determined and is maintained throughout life, although it may suffer fluctuations. The temporary (reversible) form occurs in relation to certain diseases, such as infectious gastroenteritis or intestinal inflammations of another type, as well as after taking certain medications (anti-inflammatory drugs, aspirin, antibiotics, etc.).
The symptoms that appear after the ingestion of dairy products in patients with lactose intolerance are very diverse but the most frequent are abdominal distension, pain and diarrhea.. Its severity depends on the amount of lactose ingested, the level of lactase deficiency and the susceptibility of each person.
The most effective and simple test for the diagnosis of lactose malabsorption is the breath test. It consists in obtaining samples of expired air (blowing) after the administration of a known amount of lactose. There are also other methods of detection such as the blood test (blood glucose level is measured), the genetic test (DNA is extracted from the patient to check whether it is intolerant or not) and a small bowel biopsy (determines if there is lactose in the blood). the intestinal mucosa).
The treatment consists of avoiding lactose in the diet and, in certain situations, using supplements of the enzyme (lactase) when consuming dairy products.