What is lactose intolerance?
What are the lactose intolerance symptoms?
What are the causes of the lactose intolerance?
How lactose intolerance is diagnosed?
Distribution of the lactose intolerance in the world
Which food and other products represent danger due to the ingestion of lactose?

What is lactose intolerance?

Lactose intolerance is the assembly of gastrointestinal inconveniences that are active when the organism has difficulty in digesting milk and other dairy products. Lactose is the sugar found in a natural form in milk. To digest it, the organism needs lactase,  an enzyme located in the mucous membrane of the small intestine, that transforms lactose in its two smaller units, galactose and glucose, which are well absorbed by the bloodstream. The deficiency of intestinal lactase reduces the capacity to digest the lactose, appearing then the intolerance symptoms to this compound.

Which are the lactose intolerance symptoms?

The most frequent symptoms are: flatulence, abdominal pain, diarrhea, abdominal distension and nauseas. They usually appear 30 minutes after food or medicines that contain lactose intake.  The symptoms disappear between 3 and 6 hours later, although in some cases, they can continue several days. These symptoms are due to the fact that none digested lactose in the small intestine passes to the large intestine and there is transformed by the intestinal flora bacteria, producing hydrogen and other gases.

The intensity of the symptoms changes according to the quantity of lactose ingested and the individual lactase quantity.

What are the causes of the lactose intolerance?

In general the deficiency of intestinal lactase can be classified in two large groups:

1. Primary deficiencies or adult hypo lactase.
2. Secondary deficiency. 

Primary deficiency or adult hypo lactase:

It constitutes the most frequent genetic disorder in the human, affecting more than 50% of the world population. This metabolic disorder appears when the small intestine does not have lactase enough.  It appears in people with normal intestinal lactase who lose this enzyme in a greater or smaller degree as they reach the maturity, therefore, the organism loses capacity to digest lactose. This type of deficiency used to appear along the adult age, but also might appear in the infancy or in the adolescence.

There is another type of primary deficiency which is known as congenital deficiency of intestinal lactase, in which there is a lack of the enzyme since the birth.  This deficiency is very rare, but especially severe, due to the fast dehydration caused in newborn after the ingestion of milk.

Secondary deficiency:

In this case, the reduction of intestinal lactase is not due to genetic causes, but consequence of diverse intestinal illnesses, in which there are a greater or smaller deterioration of the intestinal mucous membrane like the celiac illness, infection or severe wounds in the small intestine, gastrointestinal surgeries, irritable colon, gastrointestinal illnesses caused by malnutrition, patients exposed to chemotherapy treatments, and the like. In these cases, the intolerance is reversible; therefore, when the primary disorders disappear the intestinal lactase is recovered. In the third age is also frequent the deficiency of lactase.

How is lactose intolerance diagnosed?

Generally the withdrawal of milk from the diet is indicated and the consequences are observed. If the patient does not improve he will be indicated the habitual diagnosis that consists mainly in:

Intestinal biopsy:  it is based on the direct measure of the lactase activity in a sample of intestinal mucous membrane extracted by endoscopy.  Up to now, this test is accepted as the most reliable one.

Hydrogen breath test: The patient is orally administered between 25 and 50 grams of lactose and, subsequently, the hydrogen exhaled in the breath is measured for several hours. The level of hydrogen exhaled will depend on the quantity of none digested lactose, as a result of the intestinal lactase deficiency degree.

Inconvenient:

- Invasive technical.
- Non-homogeneous distribution of the intestinal lactase.
- It cannot be carried out in patients with anticoagulants treatments.

Hydrogen breath test

Inconvenient:

- Reduced reliability due to the frequency in false positive and false negative.
- Appearance of intestinal inconvenience, in deficient people during the test.
- Cannot be carried out in patients who are on treatment with antibiotics.
- Equipment not always available.

LACTEST S.L. is installing a new system of diagnosis that will surpass the actual inconvenience of the current systems. 

Distribution of the lactose intolerance in the world

The lactose intolerance incidence has a geographical distribution, depending directly on the ethnic group to which the person belongs, being more frequent in dark skin population, Asian and natives of America. In Spain it is estimated that the incidence of the hypo lactase in adults oscillates between the 19% and 28% of the population. It has been calculated that around the 38% of the western population and the 65% of the world population is lactase deficient.

In the following table are the incidences of this pathology in different countries

Which food and other products represent danger due to the ingestion of lactose?