Lactose intolerance: symptoms, types and foods to avoid

The lactose is a natural sugar present in the milk of mammals, to which it contributes its sweet taste, but not all people digest it correctly. Specifically, lactose is the sugar in milk and It is your most important carbohydrateformed by the union of two simple molecules, glucose and galactose.

Lactose intolerance is not a disease proper. It is a disorder caused by decreased activity of a digestive enzyme called lactase, produced in the small intestine and responsible for breaking down lactose.

What is lactose intolerance?

In order to digest lactose and subsequently absorb it, the action of lactase, which is responsible for breaking down the lactose molecule. When the lactose molecule reaches the large intestine intact, it is fermented and the classic digestive symptoms that define intolerance can appear.

This enzymatic mechanism, vital in newborns, loses effectiveness over the years in a dynamic that presents a certain logic given that, unlike other mammals, the human species is the only one that consumes milk after lactation.

Lactase deficiency, the enzyme necessary for lactose digestion, has a high prevalence in Asian and sub-Saharan populations and is much more frequent in southern Europe than in the Nordic countries. In Spain it is estimated an affectation of between 15 and 20% of the entire adult population.

Lactose intolerance: symptoms

The lactose intolerance it is often underestimated, as its symptoms can go almost unnoticed. The most frequent are

distension abdominal pain flatulence spasms acid and watery diarrhea In certain more or less chronic situations it can cause growth delays, weight disorders, malnutrition, vomiting, nausea.

When do the symptoms of lactose intolerance appear?

Depending on the cases, immediately after ingestion, or after a longer period of time depending on the amount tolerated. It can range from 30 minutes to two hours. There are individuals with intolerance who are asymptomatic for life because they do not exceed their limits.

Types of lactose intolerance

There is no single type of lactose intolerance, but several depending on the tolerance to the ingested dose and the symptoms presented. This intolerance can occur at any age: at birth, during childhood when introducing cow’s milk or as an adult.

The primary intolerance Genetics is progressive and permanent. The secondary, caused by intestinal damage, is reversible if dairy intake is temporarily avoided and the mucosa is regenerated. In congenital, which is extremely rare, lactose cannot be ingested.

Lactose sensitivity varies widely. In primary intolerance, in which lactase activity decreases with ageThere are different categories. There are people who digest up to 12 g of lactose at one time (almost a glass of milk) and others who tolerate lower amounts.

How is lactose intolerance diagnosed?

The lack of specificity of lactose intolerance requires a correct diagnosis. The most used method is the hydrogen breath test. It is based on detecting the level of this gas in the breath, since if lactose is poorly digested, it is fermented by colon bacteria and produces a lot of hydrogen, which passes into the blood and lungs and is eliminated through the breath. .

Other less common tests are the blood test or biopsy.

Foods with more lactose

Foods with a lot of lactose. Whole milk, cream, milk ice creams and béchamel present the higher concentrations.Low lactose foods. Butter, mature cheese (Manchego, Gruyère and Emmental type) or mozzarella contain a small amount. At an intermediate level are goat’s milk, yogurt and fresh cheese.

Even if a person does not consume dairy products out of ethical conviction or health, they may be consuming lactose without knowing it. This is because lactose is not only present in dairy products. It is an additive that is also found in processed foods, candies, beverages, toothpastes, and medicines. About 20% of medicines contain lactose as excipient.