We have previously explained the difference between allergy and intolerance, now let's go into the details of the most widespread intolerances in the population and their causes.

What is lactose intolerance? Because the body cannot metabolize it?

Lactose is a disaccharide, that is, a compound sugar present in dairy products and all its derivatives, formed by two simpler sugars: glucose and galactose. Normally the body metabolizes it through lactase, an enzyme produced by some bacteria such as lactobacilli and bifidobacteria. Lactase breaks the bond between glucose and galactose and allows their digestion.

When the enzyme is reduced or absent in the body, this cannot break it down and digest it so it accumulates in the intestine where it is fermented and produces gas, causing intolerance that manifests itself with various symptoms: abdominal cramps, constipation, nausea, diarrhea, meteorism, swelling, tiredness or headache. The diagnosis is made with a specific test called the H2-Breath Test, also known as a breath test because after drinking a substance containing 20-30 grams of lactose the patient will blow into a bag at regular intervals, circa 30 minutes for 3-4 ore, to evaluate the presence of hydrogen (H2). Depending on the result, a mild or severe intolerance can be identified, but to understand whether it is a congenital or acquired form, genetic testing is necessary.

About the 50% of the Italian population suffer from lactose intolerance, but gluten intolerance also affects many people, increasing every year.

What is gluten intolerance? How it differs from celiac disease?

Celiac disease and gluten intolerance are disorders associated with the same protein that can often be confused with each other, but actually very different. In fact, celiac disease is a chronic autoimmune inflammation of the small intestine triggered by the ingestion of gluten which reduces intestinal villi; it interferes with the absorption of nutrients and can affect not only the intestine, but also other organs. Intolerance, on the other hand, does not depend on immunity but is a phenomenon of hypersensitivity to gluten present in some cereals such as wheat, rye, barley and spelled, due to an accumulation that manifests itself with intestinal symptoms.

The diagnosis is carried out by exclusion! First, celiac disease is excluded by blood analysis and biopsy carried out after a gastroscopy and later, we proceed with a gluten-free diet to reintroduce it after a certain period of time. If symptoms reappear after reintroducing it and celiac disease has been ruled out, it's about intolerance.

But be careful! A gluten-free diet does not always solve the problem because sometimes it is not the fault of gluten but of fructan: a sugar found in barley, rice and wheat or some vegetables and legumes, as our popularizer Irene explains in this article. (https://www.noidiminerva.it/celiachia-o-problemi-con-il-fruttosio/)