Gluten-free diet: what you need to know

What is gluten?

Gliadins and glutenins are the gluten constituent proteins. They are also indicated with the name of prolamines, wanting to refer to their high content in proline and glutamine.

Gluten was first described by Beccari in 1745 as a set of protein substances which separate from the starch when kneading the flour under a fine jet of water. As we have all experienced, gluten comes in the form of whitish, rubbery mass. Soft wheat (the one from which we make bread and baked goods) generally contains 8 to 12% of it. The durum wheat, with which we make pasta, can contain up to 15% gluten.

Gluten is essential for the purposes of baking and pasta making. The ability of gluten proteins to bind to each other by means of chemical bonds is the basis of the rheological properties (i.e. characteristics such as viscosity, elasticity and cohesion) of wheat flour and other flours derived from gluten cereals.

Bread, pasta and gluten

Gluten when baking gives extensibility and elasticity to the dough that swells thanks to the carbon dioxide developed by the fermentation action of yeasts. On the package of flour, lbread-making index it is indicated with the letter W and is associated with a high gluten content. Flour with a high W value is able to absorb a lot of water giving rise to a resistant dough and tenacious. In this case the leavening will be slow because the gluten network is dense and resistant. On the contrary, a low W indicates a flour that needs little water and that rises quickly. The bread that will be obtained from this dough will be light and not very consistent.

Digest gluten

Gluten it is not an easy protein to digest. This was also stated by Alessio Fasano (professor of pediatrics, gastroenterology and nutrition at the Massachusetts General Hospital for Children). After specializing at the Federico II University of Naples, Fasano dedicated his career as a doctor to study of celiac disease and in America he founded the Center for Celiac Research. It is in this center that the most in-depth research on celiac disease is carried out.

In his beautiful book entitled “Gluten free” Fasano states that if we put gluten in a laboratory beaker together with our digestive enzymes we will not be able to digest it completely. Instead, large undigested protein fragments (called peptides) will remain. Among the various peptides that are formed there is one composed of 33 amino acids and therefore known as 33-mer which is considered one of the main factors triggering celiac disease.

Is eliminating gluten a healthy choice?

Prescribing a gluten-free diet is a medical act in all respects. It should never be adopted without first consulting a gastroenterologist. The cases in which a gluten-free diet should be prescribed are the following:

• Celiac disease
• Non-celiac gluten sensitivity
• Gluten ataxia
• Allergy to gluten

Celiac disease

There celiac disease is an autoimmune disease characterized by the production of autoantibodies and the flattening of intestinal villi in genetically predisposed subjects. In this case, the gluten-free diet is a must. For the purpose of diagnosis, the following should be sought:

• specific serological markers (anti-tissue transglutaminase or anti-tTG antibodies, anti-endomysium or EMA antibodies, anti-deaminated gliadin or AGA II antibodies);
• damage to the intestinal mucosa with flattening of the villi (this is assessed by esophagastroduodenoscopy with duodenal biopsies);
• the onset of signs and symptoms involving the gastrointestinal system;
• the presence of other autoimmune diseases, such as type I diabetes mellitus or Hashimoto’s thyroiditis.

Non-celiac gluten sensitivity

There gluten sensitivity non-celiac is a different condition from celiac disease. Recent studies document that while the Adaptive Immune System (T lymphocytes and B lymphocytes) is involved in celiac disease, non-celiac gluten sensitivity is controlled by the oldest part of our immune system, the one that governs the innate immune response.

Although in gluten sensitivity i gastrointestinal symptoms very closely resemble those associated with celiac disease, there is no presence of auto-antibodies directed against our intestinal structures. If in the case of celiac disease there is a diagnostic and therapeutic protocol widely shared by the scientific community, in the case of gluten sensitivity the diagnosis is made by exclusion. To confirm the suspicion formulated on the basis of the clinic, a elimination diet followed by a provocation test in which the supervised reintroduction of the offending foods is carried out.

Confirmation occurs when i symptoms disappear with the elimination of gluten and appear again with its reintroduction.

Gluten ataxia

L’gluten-related ataxia it is an autoimmune disease just like celiac disease. In this case the damage is not at the level of the intestinal villi. IS instead the cerebellum is involved and the clinical manifestation is ataxia, a term used to indicate the lack of muscle coordination resulting in difficulty in performing voluntary movements.

Allergy to gluten

L’wheat allergy it is an allergy caused by the proteins present in the flour. Amylase inhibitors, for example, are particularly allergenic. Between children the prevalence rate fluctuates between 3 and 4%. The prevalence decreases with age so much so that in the general population it is affected only 0.4% of individuals.

Like all food allergies, wheat allergies also trigger one more immediate immune response compared to that induced by celiac disease or gluten sensitivity. The reactions are different depending on whether the flour is inhaled or ingested.

The allergic reaction toinhalation of wheat flour it affects bakers and manifests itself with breathlessness, hives and skin rash. It is considered a ffootprint of occupational asthma. Those who are allergic to wheat are generally also allergic to barley, rye and oats since these grains contain similar proteins.

Aside from baker’s asthma, wheat allergies can affect several districts: the skin, intestines and lungs. They range from an annoying skin itch to anaphylactic shock. Among the most common symptoms should be mentioned

• nasal congestion;
• itching and swelling in the mouth and throat;
• watery and itchy eyes;
• stomach cramps;
• diarrhea;
• nausea and vomit;
• urticaria.

While in celiac disease the auto-antibodies belong mainly to the IgA class, in wheat allergy immunoglobulins of class E or IgE are involved.

There diagnosis it is based on the skin prick test, on the search for specific antibodies in the blood, on the adoption of a diet that excludes wheat and on its reintroduction under medical supervision (challenge test) in search of symptoms that confirm the presence of an allergic reaction. There therapy consists in the exclusion of wheat together with the precaution of carrying with you a dose of self-injectable adrenaline to be used when needed.

Conclusions

Celiac disease, non-celiac gluten intolerance, gluten-related ataxia and gluten allergy are the only clinical conditions in which gluten must be eliminated from the diet.

In the case of non-celiac gluten intolerance this is only a temporary exclusion since the symptoms are significantly attenuated when modern grains are replaced with ancient grains (see Senator Cappelli and Tuminia).

Gluten free diet: what to eat and what to avoid

The foods allowed on a gluten-free diet are:

• Fruits and vegetables
• Legumes (lentils, beans, peas, chickpeas …)
• Oily fruit (walnuts, almonds, pistachios, cashews …)
• Meat and fish
• Milk and dairy products

All pseudo-cereals naturally gluten-free such as:

• Amaranth
• Corn
• Rice
• Mile
• Buckwheat
• Quinoa

Instead, they must be eliminated:

• Wheat (also referred to as wheat)
• Spelled
• Barley
• Rye
• Einkorn
• Kamut
• Triticale
• Bulgur
• Oats
• All products made from these derivatives: seitan, semolina, semolina, bread, rusks, baked goods, couscous, muesli, porridge.

Does the gluten-free diet make you lose weight?

The gluten-free diet was also adopted by those who do not need it: on the shelves of supermarkets, in fact, gluten-free foods are indicated as diet foods, an expression erroneously interpreted as foods suitable for those on a diet for slimming purposes. In fact, dietary foods mean all those products to which dietary properties are conferred and intended for a specific diet for people who are in particular physiological or pathological conditions. In the case of foods intended for celiac subjects, the characteristic is the total absence of gluten. Therefore, the caloric value of a gluten-free snack is not inferior to that of a snack containing gluten: indeed, the opposite may be true.

The gluten-free diet it does not make you lose weight by itself. Weight loss is made possible when the energies introduced with food are lower than those spent throughout the day (negative energy balance). In other words, to lose weight we have only two strategies: the calorie restriction and theincrease in energy expenditure.

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