Lactose intolerance becomes evident when an organism has a pathologic response to the sugars found in milk and cannot digest the glucose (lactose).
The signs and symptoms of lactose intolerance usually begin 30 minutes to two hours after drinking milk or having dairy products (yogurt, cheese, cream, etc.) or other products containing lactose (pastries, ice cream, chocolate). Some of the most characteristic symptoms of lactose intolerance are: stomachache, nausea, diarrhea and gas and its effects vary from person to person in intensity.
Causes and risks
The causes of lactose intolerance can be several, but in all cases it is due to a lack of the enzyme lactase. There are three types of lactose intolerance. Different factors cause the lactase deficiency underlying each type.
- Innate (primary) lactose intolerance: This is the most common type of lactose intolerance. In this type of inherited intolerance, the small intestine starts producing plenty of lactase but lactase production falls off sharply., Thus, there is very little lactase available and lactose intolerance increases making milk products difficult to digest by adulthood.
- Acquired (secondary) lactose intolerance: Acquired or secondary lactose intolerance is not due to hereditary factors. It can develop during a person´s lifetime after an illness, injury or surgery involving the small intestine. Among the diseases associated with secondary lactose intolerance are celiac disease, bacterial overgrowth and Crohn´s disease.
- Congenital (alactation) lactase deficiency: Congenital lactase deficiency (congenital lactose intolerance) occurs in babies and is caused by a complete absence of lactase activity. This means that in the intestine, there is no lactase enzyme that works correctly. It occurs very rarely but babies afflicted by this deficiency react severely to the most minimum amount of lactose and suffer from severe diarrhea, dehydration and malnutrition in the first weeks of life.
In only one of the three types of lactose intolerance can this disorder be prevented. This can be done by preventing the mentioned diseases, some of which are also congenital. Patients can improve over time with the proper treatment and diet.
GENE OR REGION STUDIED