Lactose intolerance: what is lactose intolerance, symptoms, diagnosis, dietary advice and natural advice from


They’ve been telling us since we were born: milk is the most complete food, essential for growth, essential for the well-being of bones. Yet many people, half of the world population, has milk intolerance and dairy intolerance. It is an intolerance that is not easy to diagnose, because the symptoms are varied and not always immediately attributable to the enzymatic deficiency that is the cause.

Lactose intolerance is the most common enzyme intolerance, it is often hereditary and is very common in Asia and some regions of America. In Europe it is more frequent in the Mediterranean areas, including Italy, and less so in the Northern countries (it is curious but intolerance seems more frequent precisely where the sun is more intense and vitamin D for the bones is therefore easier to store thanks to exposure to its rays). It is a kind of intolerance that not only affects children, but often affects adults, since it can also manifest itself in old age.

First of all: what is a food intolerance? intolerances include the set of disorders of different nature, localized in various organs, resulting from the ingestion of certain foods. They differ from allergies in that they are not due to immune-type mechanisms and regress with the suspension of the responsible food. The manifestations are variable from subject to subject and can change over time in the same individual.

Symptoms encountered during a food intolerance

  • respiratory system (rhinitis, sinusitis, in some cases also dry, irritating cough, asthma syndrome),
  • gastro-enteric system (colitis, irritable bowel, swelling, meteorism, constipation, diarrhea, pain abdominal, gastritis, anal itching),
  • genitourinary system (decreased libido, dysuria, recurrent cystitis, recurrent vaginitis, recurrent candidiasis),
  • skin system (eczema, acne, pruritus, seborrhea),
  • musculoskeletal system (cramps , spasms, bone pain, muscle pain),
  • cardio-circulatory system (arrhythmias, extrasystole palpitations).

Lactose: what it is and where it is found

Lactose is a sugar composed of a unit of beta galactose and glucose linked in β 1 → 4. Constituent of milk, lactose is synthesized by the mammary gland starting from blood glucose according to the following scheme: glucose, glucose phosphate, UDP glucose, UDP galactose, galactose, lactose.
Lactose is the main sugar in cow’s milk, it constitutes 8% of mammalian milk, but in addition to milk and derivatives, it is also used as a diluent for tablets but also in various industrial food processing (but must be indicated among the ingredients).

Lactose intolerance: what it is and what it is

Before being absorbed and used by the body, lactose must be broken down into glucose and galactose, two simple sugars. To do this, you need an enzyme, lactase, present on the surface of the intestinal villi. Lactose intolerance is caused by lacks of enzyme lactase, that make milk digestion impossible.

There are three forms of lactose intolerance:

  • the genetic form also called primary lactose intolerance, due to a deficit in the production of lactase. It can manifest itself in the child during weaning or later in the adult person;
  • the acquired form, called secondary, a consequence of other pathologies, such as inflammation of the intestine, enteritis, Crohn’s disease, celiac disease. It is a transient form that disappears when the disease heals (except for Crohn’s disease and celiac disease, which are chronic disorders);
  • the form of genetic and congenital origin, with the total absence of the lactase enzyme and the permanent inability to transform lactose into simple sugars.

The older we become, the more we lose the ability to digest milk. The enzyme lactase is present at its maximum from the twenty-third week of gestation, and its activity increases until birth. The supply of milk is physiological in the first phase of the individual’s life, which doubles its weight in about 6 months, after which milk production in the mother is spontaneously reduced. After weaning, the activity of the lactase enzyme begins to decrease with a genetically programmed reduction, but variable from individual to individual. The progressive decrease of intestinal lactase causes a malabsorption of this disaccharide.
It should also be remembered that each species creates milk to satisfy the needs of its species. We, on the other hand, are the only species in nature that continues to consume milk even after weaning, or rather “stealing” the milk from other mammals that are nursing the puppies of their species.

A large percentage of individuals are intolerant already at birth, because nature has not endowed them with the lactase enzyme, so from weaning the mother will notice this deficit, which in the newborn often causes bloating, meteorism, dysentery and abdominal colic.

The difficulty of digesting lactose

As early as 1965, researchers at the John Hopkins Medical School discovered that a large number of subjects with gastro-duodenal and colitis disorders did not tolerate milk, or rather could not metabolize lactose, a complex sugar found in milk and its derivatives. .
It was first observed that under normal conditions, the mucous membrane of the small intestine is unable to absorb the voluminous molecules of lactose and is therefore forced to transform them into monosaccharides, or simple sugars, glucose and galactose, in order to be able to disassemble them and convert them into energy, through the indispensable chemical action of an enzyme called lactase (or β galactosidase); the cleavage of lactose by β galactosidase takes place in the outer surface of the epithelial cells found on the lining of the small intestine.
However, this enzyme can be deficient in many individuals and sluggish in the majority of humanity. In practice, if individuals with severe deficiency of the lactase enzyme drink a cup of milk, eat an ice cream, a dessert made with milk or even drink the “sacrosanct” cappuccino in the morning, not being able to metabolize lactose, they will accumulate it. in abnormal quantities in the intestine, causing fermentation, meteorism, flatulence: this is because in the absence of beta galactosidase the lactose is processed and fermented by the bacterial flora contained in the intestine, resulting in the production of gas and pain.

Lactose intolerance: symptoms and clinical picture

If not enough lactase is produced, or not at all, some of the lactose is not broken down; therefore it arrives undigested in the colon, and due to the osmotic effect it draws a quantity of water into the intestinal lumen, consequently causing a fermentation process by the bacterial flora. In particular, the bacterial flora of the caecum hydrolyzes food lactose and partially converts it to lactic acid, which in turn can give rise to the formation of organic acids (propionic, acetic, butyric); the final degradation takes place in the colon, where hydrogen, methane or carbon dioxide is produced, and water is recalled.

Lactose intolerance, symptoms. Symptoms are dose-dependent: the greater the amount of lactose ingested, the more evident the symptoms, which can include flatulence, diarrhea, bloating, bloating and abdominal pain. These disorders can be confused with those resulting from irritable bowel syndrome, ulcerative colitis or other intestinal diseases. Among the extra intestinal symptoms, on the other hand, there are: headache, asthenia, loss of concentration, but also not uncommon a reaction on the skin, such as eczema.

The clinical picture is characterized by abdominal swelling and distension, diarrhea, cramp-like abdominal pain, flatulence. A heavy consumption of lactose tends to cause diarrheal disorders due to the degradation carried out by the flora and the resulting intestinal acidification. The assimilated lactose as it is is not metabolized and is found in the urine (lactosuria).

Lactose intolerance: the diagnosis

The simplest and most reliable test for diagnosing lactose intolerance is the H2 breath test, which evaluates the presence of hydrogen in the exhaled air before and after lactose administration. In case of lactose malabsorption resulting from the absence of the enzyme responsible for its metabolism (lactase), fermentation processes occur in the intestine, with increased production of hydrogen, which is absorbed into the circulation and eliminated through the lungs with the breath. Under normal conditions, a minimum quantity of hydrogen is produced in the intestine, therefore its increase in the breath after the intake of lactose demonstrates malabsorption of various degrees: from mild to moderate to severe.

Lactose intolerance foods to avoid and tips of

In the event of a diagnosis of lactose intolerance, the therapy is almost exclusively dietary, with total or partial exclusion (obviously in the latter case being careful not to exceed the quantity of lactose that can be assimilated by one’s body!) Of milk and derivatives, especially cheeses fresh, ice cream, milkshakes, pastry creams and cream. If the intolerance is mild, it is possible to control the symptoms by drinking milk low in lactose and replacing fresh cheeses with hard cheeses, which are better tolerated in non-severe forms as with aging the quantity of lactose is drastically reduced. Yogurt can also be tolerated, due to the presence of bacterial lactase, that is, enzymes produced by ferments (bacteria) that transform lactose into glucose and galactose. Otherwise, if the intolerance is serious, it is essential to completely eliminate milk, cheese, derivatives (béchamel, cream, chocolate, …) and everything that may contain traces of lactose: read the ingredients of the food is important to check that lactose is not present. Lactose can in fact be present in various food products, to avoid, also if it is present in small quantities, such as:

  • packaged sweets (biscuits, chocolate, candies, shortcrust pastry, brioches, snacks, mixes for cakes, crackers, muesli, special breads, bread rolls);
  • cured meats and sausages (cooked ham, mortadella, sausage, wurstel, stuffed pasta, ready-made hamburgers);
  • prepackaged foods, where milk is used as a preservative;
  • products for children (biscuits, pastries, homogenized, freeze-dried);
  • many supplements, dietary and protein products;
  • lactose can be found as an excipient in drugs.

Those who are lactose intolerant do not necessarily have to give up yogurt, butter and mozzarella, as long as they are “lactose free”; as for the alternatives to milk there are rice, almond, oat, walnut, soy milk, and many others, but the consumption of these products must be carefully evaluated because they have a high glycemic index. Homemade desserts, on the other hand, can be prepared for example by replacing sunflower oil instead of butter. However, it should be noted that those who avoid milk and dairy products should check to take or supplement vitamin D if necessary, for the benefit of their bones.

On you can also find Intolerance digest: a naturally lactose and gluten free supplement, based on alpha galactosidase, beta galactosidase and titrated fennel dry extract. Specifically, for 2 capsules here is the nutritional information: Beta-galactosidase 90 mg (equal to 9000 ALU) Alpha-galactosidase 20 mg (equal to 600 GalU) Fennel E.S. tit. 0.9-1.1% in essential oil 200 mg equal to essential oil 2 mg. It is advisable to take 1-2 capsules of intolerance digest before main meals or in any case with food containing lactose or non-digestible carbohydrates (intolerance digest is also useful for those who are sensitive to gluten!). It can also be used during breastfeeding and pregnancy.

As we explained a little while ago, galactosidase is the specific enzyme that hydrolyzes lactose into galactose and glucose and administered to subjects who have a low lactase activity serves to favor the splitting of lactose, which is very difficult for them. The dry extract of fennel instead helps the physiological elimination of gases.

The Intolerance digest supplement, made thanks to Italian phytopreparators, can also be accompanied by Erboflora Intolerancethe first synbiotic (probiotic and prebiotic, therefore more than classic lactic ferments!) Without sugar suitable for regenerating the bacterial flora of those with the intestine sensitive or some intolerance that strains your intestines (intestinal dysbiosis).

Dr. Laura Comollo

For any clarification or for more information Contact us.

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