Gluten
Gluten is a group of small proteins, contained exclusively in the seeds of dry cereals, mainly wheat, but also barley and rye, as well as any of their varieties and hybrids (such as spelt, spelled, kamut, triticale, and farro), and some varieties of oats.
Gluten is made up of gliadins and glutenins. It represents 80-90% of the total wheat proteins. It is appreciated for its unique viscoelastic qualities, which provide elasticity to the flour dough, allowing it to be combined with fermentation the bread obtains volume, as well as the elastic and spongy consistency of breads and baked doughs.
Gluten is not essential for humans. It is a mixture of proteins of low nutritional and biological value, with low quality due to deficiencies in essential amino acids, so from the point of view of nutrition its exclusion from food does not represent any problem and can easily be replaced by other animal or vegetable proteins when a gluten-free diet is necessary. Only celiacs and people with non-celiac gluten sensitivity experience symptoms and various health disorders if they do not strictly adhere to the gluten-free diet for life. As an alternative, these people should choose gluten-free cereals (minor cereals and pseudocereals), whose nutritional quality is also superior to that of wheat, both due to the essential amino acid composition and bioavailability or digestibility.
The number of people affected by the various gluten-related disorders is steadily increasing. However, due to the limited knowledge about these disorders among health professionals, which tends to be perpetuated, and despite Although the number of diagnoses has increased compared to previous years, today practically all real cases remain unrecognized, undiagnosed and untreated. The figures of children who remain undiagnosed range between 80% and 90%. Most of the affected people, especially from two years of age, only present mild, intermittent or even absent digestive symptoms, probably due to to the opioid effect of gluten, which masks intestinal damage, although they do develop other associated disorders that can affect practically any organ. After a long history of various health complaints and a long pilgrimage through a multitude of consultations with various specialists for years, without receiving adequate medical support, most people affected end up resorting to a gluten-free diet and self-diagnosis, while many others are people who have become used to living with a state of chronic ill health as if it were normal.
Gluten can also affect people with celiac disease when inhaled.
Neurological disorders caused by gluten consumption are called neurogluten. The chances of physicians suspecting a gluten relationship are very low, especially when there are no digestive symptoms or intestinal injury. Despite evidence-based in documented cases and studies with small series of patients, the number of neurologists who take gluten neurotoxicity into consideration in people with celiac disease or non-celiac gluten sensitivity is very small. According to neurologist Marios Hadjivassiliou, a world pioneer in the study of gluten ataxia, "That gluten sensitivity is considered primarily a disease of the small intestine is a historical error (...) it may be primarily, and sometimes exclusively, a neurological disease".
Composition
Wheat gluten is made up of proteins called glutenins and gliadins (90%), lipids (8%), and carbohydrates (2%). Gliadin is the alcohol-soluble fraction of gluten and contains most of the products that are toxic to people with a genetic predisposition; it also causes increased intestinal permeability (involved in the development of autoimmune diseases, cancer, infections and allergies) regardless of genetic predisposition, that is, both in celiac and non-celiac patients. Other cereals, due to their taxonomic proximity, contain homologous toxic peptides: barley (hordeins), rye (secalins), oats (oats) and their varieties and hybrids, such as kamut and triticale. All of these proteins are collectively referred to as gluten.
Gluten is responsible for making wheat flour bread-making, since it contains a large amount. Glutenins give bread dough elasticity, so that when it is stretched it tends to recover its original shape. Gliadins are stabilized by intramolecular disulfide bonds and provide stickiness to the dough, at the same time that they are responsible for its extensibility, that is, it extends without breaking. Throughout the 19th and 20th centuries, active genetic selection and direct genetic manipulation have greatly modified the original wheat varieties (Triticacee), from a few grains with low gluten content to large wheat harvests highly enriched with gluten, with the aim of facilitating the preparation of the doughs and obtaining attractive products for the consumer from the gastronomic point of view. The current criteria for the selection of wheat do not take into account its nutritional value, but its qualities from the functional point of view demanded by the food industry (determined by a high gluten content) and the low economic cost.
Currently, gluten represents 80-90% of the total protein in wheat. This situation may have been the trigger for the large increase in the frequency of celiac disease, especially in populations whose genetic inheritance is derived from groups very ancient that did not successfully adapt to tolerate this protein.
Nutritional properties
Gluten proteins are of low quality, with low nutritional and biological value.
The ability of gluten to supply amino acids that the body can use is very limited, according to the results of the new method for measuring protein quality promoted by the Food and Agriculture Organization of the United Nations (amino acid score Digestible Indispensables, or DIAAS), well below the scores obtained by other proteins of animal (such as milk) or vegetable (such as peas) origin.
Gluten is deficient in the essential amino acid lysine. There are ten amino acids that are considered essential, since animals cannot synthesize them and must obtain them through food. If the levels of at least one of these essential amino acids is deficient, the others are broken down and excreted, which limits growth in children and causes nitrogen to be lost from the diet. To compensate for this deficiency, it is It is necessary to supplement with proteins from other foods, such as legumes.
Use
Gluten is in high demand all over the world, mainly by the food industry but also by other types, due to its low economic cost and its unique viscoelastic and adhesive properties.
Food industry
The physical characteristics of gluten facilitate the production of processed foods, fast food and food additives, whose consumption has increased dramatically due to the process of global industrialization and the westernization of the diet. As an additive, it is used to confer viscosity, thickness or volume to a large number of food products, which causes the presence of toxic proteins for a part of the population in less suspicious products. More than half of the foods currently on the market contain wheat gluten, barley, rye or oats as a thickener or binder, in the form of cross-contamination or even adulteration. They pose a serious risk to the health of celiac patients and people with non-celiac gluten sensitivity, which is why a rigorous control of the gluten content is necessary for their certification as foods suitable for consumption by celiac patients.
Gluten is also present in the communion wafers that are offered during the Eucharist or Christian mass, since they are unleavened bread (without yeast) made with wheat flour.
Biodegradable plastics
Gluten has been used for years in research to make biodegradable plastics for food preservation and various other uses, as an alternative to petroleum-based plastics. Its impact on people with gluten-related disorders Gluten, as well as its use in a large and growing number of food and other products, is a cause for concern that needs to be assessed and regulated.
Other uses
Gluten is also used in the manufacture of pharmaceuticals (including prescription and over-the-counter drugs, gargles and mouthwashes, vitamin and mineral supplements, herbal products, dietary supplements, adhesive bandages, tapes, and sanitary adhesive strips).), all kinds of cosmetic and personal care products (lipsticks, lip balms and glosses, toothpaste, mouthwashes, skin and hair care products, etc.), feed and feed for farm animals and pets, dog shampoos and children's modeling paste (such as Play-Doh), among others.
Gluten-Related Disorders
Since the first decade of the 21st century it has become clear that, along with celiac disease, there are other diseases caused by gluten ingestion. “Gluten-related disorders” is the currently accepted term for them. It is not recommended to use the term "gluten intolerance", due to its lack of precision.
The London (February 2011) and Oslo (June 2011) consensus recognize three main forms of gluten-related disorders:
- wheat allergy,
- autoimmune form (including celiac disease, herpetiform dermatitis and gluten ataxia)
- sensitivity to non-Celiac gluten.
Wheat allergy (AT)
It is the least frequent. It is an adverse immune reaction to wheat proteins, mediated by IgE-type antibodies against various protein components of the wheat grain. Its manifestations include classic food allergy, gastrointestinal, skin, and respiratory symptoms; wheat-dependent exercise-induced anaphylaxis (AIEDT); occupational asthma (baker's asthma) and contact urticaria. The diagnosis is made through skin prick tests or by blood determination of antibodies against IgE class wheat proteins. Challenge tests are often necessary.
The autoimmune form, including celiac disease, dermatitis herpetiformis, and gluten ataxia
Celiac Disease (CD)
Celiac disease has traditionally been considered a digestive disorder only, but it is now known that it is really a chronic, multi-organ, autoimmune disease that affects the intestine and can damage virtually any organ or tissue. It is induced by the ingestion of gluten, in people with a genetic predisposition. Although there is a "permanent intolerance" to gluten, it is not a simple food intolerance, much less an allergy. Without strict and sustained treatment for life, it can cause very serious health complications, including various types of cancer (both digestive system, with an increased risk of 60%, like other organs), neurological and psychiatric disorders, other autoimmune diseases and osteoporosis.
Celiac disease can cause very varied symptoms and/or associated diseases. A large part of celiac patients are completely asymptomatic at the digestive level, for long periods of time. The multiple associated diseases usually precede the appearance of celiac disease, although they can also manifest simultaneously and even after diagnosis. Cases with a classic presentation, which include manifestations of a severe malabsorption syndrome with steatorrhea and signs of malnutrition, have positive serology. (transglutaminase greater than 2-3 U/ml) and villous atrophy, are practically exceptional, especially from the age of 2 years.
This is one of the most frequent genetically based diseases, with an average prevalence of 2% in the general population, and it can appear at any age in life. The advances made in recent years in the identification of the multiple manifestations of celiac disease and the reform of diagnostic protocols have not yet reached the majority of professionals to whom the patient goes to consult for the varied and diverse discomforts that presents. The average delay between the onset of symptoms and the time of diagnosis is, on average, about 20 years. Approximately 83% of cases remain undiagnosed today.
The only treatment currently available consists of following a strict gluten-free diet and maintaining it for life, whose continued compliance produces an improvement in symptoms and prevents or reduces the appearance of numerous associated diseases and complications. Likewise, the delay in the diagnosis of celiac disease increases the probability of developing cancers. The protective effect of a gluten-free diet is especially effective when started during the first year of life.
Dermatitis Herpetiformis (DH)
Dermatitis herpetiformis is the skin manifestation of celiac disease. It occurs in about 25% of patients with celiac disease, and can appear at any age in life. It is so characteristic that it is considered "celiac skin disease", as well as the "visiting card" of the celiac patient, since its finding appears only in celiac individuals.
Exposure to ultraviolet rays from sunlight and repeated skin microtraumas are external factors that favor the appearance and maintenance of the typical skin lesions of DH.
Dermatitis herpetiformis disappears completely with the gluten-free diet (GFD), which is its best and only treatment. It can reappear in patients who appear to be following the GFD well, due to both voluntary and inadvertent violations of the diet.
Gluten Ataxia (GA)
Gluten ataxia is an autoimmune disease characterized by irreversible damage to the cerebellum, due to the fact that the immune system itself mistakenly attacks and destroys neurons called Purkinje cells. It manifests as progressive cerebellar ataxia (balance disturbance, clumsiness, loss of coordination), or more rarely in combination with myoclonus and palatal tremor, all regardless of the presence or absence of intestinal involvement.
As with dermatitis herpetiformis, less than 10% of patients experience digestive symptoms, but approximately one-third show varying degrees of intestinal involvement. It can occur in patients of all ages, including children.
The current recommendation is that patients with progressive cerebellar ataxia should be evaluated for celiac disease.
Treatment consists of a gluten-free diet in all cases, even if there is no intestinal involvement (both celiac and non-celiac). The response to treatment depends on the duration of ataxia before diagnosis. cerebellar neurons is the result of prolonged exposure to gluten and is irreversible. Early diagnosis is essential, at the first symptoms and before the death of neurons is complete. Early diagnosis and treatment achieve the arrest of autoimmune process and symptomatic recovery of the patient. Conversely, if the diagnosis is made late, when a considerable number of neurons have already been destroyed, the response to the gluten-free diet is poor or absent. The main cause of lack of improvement on the gluten-free diet is due to transgressions, both willful and inadvertent (light diet).
Non-celiac gluten sensitivity (NSG)
Non-celiac gluten sensitivity is possibly immune-mediated. It is currently the most common form of gluten-related disorder, with an estimated prevalence 6-10 times that of celiac disease (up to 13% of the population). It is referred to by some as sensitivity to gluten (SG), or better as non-celiac gluten sensitivity (SGNC), a term accepted by most authorities on this matter.
An increasing number of people suffer from a collection of gastrointestinal (some attributed to irritable bowel syndrome, or IBS) or other symptoms (which can affect virtually any organ) that improve or disappear completely after removing gluten from the diet and reappear when eating it again. The diagnostic process is usually based on the exclusion of celiac disease and wheat allergy, as more related conditions, and on the response to a gluten-free diet. However, patients usually remain in a "no man's land". ", without recognizing or diagnosing by specialists, "orphans" of adequate medical care and treatment. This lack of support from health professionals is the reason why most of these people end up resorting to the gluten-free diet and the "self-diagnosis" of gluten sensitivity, after a long and unsuccessful pilgrimage through numerous consultations with various specialists.
As with celiac disease, non-celiac gluten sensitivity can develop both digestive and non-digestive symptoms.
Non-digestive symptoms may include any of the following: headache or migraine, brain fog, chronic fatigue, fibromyalgia, joint or muscle pain, numbness in legs or arms, tingling on the extremities, dermatitis (eczema or skin rash), atopic disorders, asthma, rhinitis, allergy to one or more inhalants, foods or metals (such as dust mites, grasses, parietaria, hair of dogs or cats, shellfish or nickel), associated food intolerances (mainly lactose intolerance), depression, anxiety, anemia, iron deficiency, folic acid deficiency, eating disorders, other neurological disorders and psychiatric (such as schizophrenia, autism, peripheral neuropathy, ataxia, attention deficit hyperactivity disorder, hallucinations, which some authors have called "gluten psychosis").
Currently, the only therapy that exists for celiac patients or patients with non-celiac gluten sensitivity consists of establishing a strict gluten-free diet for life.
Neurological disorders: neurogluten
Neurogluten is the term used to refer to the various neurological disorders caused by gluten consumption, that is, those that affect some organ or tissue of the nervous system. They can develop regardless of whether the person has digestive symptoms or injury intestine, or the presence of antibodies in the blood. In other words, both in celiac and non-celiac patients, the disease recognized since 2010 called non-celiac gluten sensitivity, in which all tests for celiac disease are negative and it is diagnosed by improvement when gluten is strictly removed from the diet.
Gluten is able to cross both the intestinal barrier and the blood-brain barrier, as demonstrated in studies in rodents and by the presence of anti-transglutaminase 6 antibodies in the brains of people with gluten ataxia.
The first descriptions of neurogluten date back to 1966, with gluten ataxia being the best known and most studied disorder. Other neurological or psychiatric disorders that are currently being associated in some cases with neurogluten include peripheral neuropathy, epilepsy, multiple sclerosis, dementia, Alzheimer's, parkinsonism, schizophrenia, autism, hyperactivity, obsessive-compulsive disorder, Tourette syndrome, hallucinations ("gluten psychosis"), cerebral palsy, chorea (involuntary abnormal movements of the feet and hands), Huntington's disease (also called Huntington's chorea), opsoclonus (involuntary eye movements), dysarthria (impaired articulation of words), sensorineural hearing loss, hemiparesis (decreased motor strength or partial paralysis of one arm and one leg on the same side of the body), mononeuritis multiplex (damage to at least two separate areas of the nervous system), amyotrophic lateral sclerosis (progressive muscle paralysis), other neuromuscular diseases (polymyositis, dermatomyositis, and inclusion body myositis), sleep disorders, and cerebral venous sinus thrombosis (blood clot in an area at the base of the brain.)
The chances that doctors suspect a relationship with gluten are very low, especially when there are no digestive symptoms or intestinal damage, having a certain advantage of being recognized and diagnosed in patients who do experience digestive discomfort. Despite the Evidence based on documented cases and studies with small series of patients, the number of neurologists that consider gluten neurotoxicity in people with celiac disease or non-celiac gluten sensitivity is very small. This is due to the fact that in medicine, action is based on more solid scientific demonstrations.
Nervous system regeneration on a gluten-free diet is slow, and improvement in neurological symptoms takes time to be noticed, in contrast to severe digestive symptoms, which usually improve almost immediately. Sometimes recovery of the nervous system is not achieved or it is only partial, as occurs when the diagnosis is delayed in gluten ataxia, but the strict withdrawal of gluten prevents the progression of neurological damage.
Tiny amounts of gluten, such as those found in most products labeled "Gluten-Free," can keep the immune system response activated i responsible for neuronal damage.
Although when talking about "Gluten Free" is thought to be completely gluten-free, with current detection methods it is impossible to test a zero level of gluten in food. Consequently, "gluten-free" is not synonymous with "zero gluten". Laws generally allow up to 20 ppm, i.e. 20 parts per million or 20 milligrams of gluten per kilogram of product. This means that a minimal level of gluten contamination is present in the daily diet.
Increased intestinal permeability
Gluten and certain intestinal bacteria are the two most potent factors that cause increased intestinal permeability, regardless of genetic predisposition, that is, both in celiac and non-celiac patients. This increase in intestinal permeability Intestinal permeability causes substances to pass into the blood that should not pass (toxins, chemicals, microorganisms and incompletely digested food) and that, depending on the person's genetic predisposition, various health disorders can develop.
Currently, there is evidence that impaired intestinal permeability is involved in the development of the following diseases:
- Autoimmune diseases, such as celiac disease, type 1 diabetes, rheumatoid arthritis, ankylosing spondylitis, intestinal inflammatory disease (Crohn's disease), systemic erythematous lupus and primary sclerosing colangitis.
- Cancers, such as glioma (brain cancer or spinal cord), breast cancer, lung adenocarcinoma, ovarian cancer, pancreatic cancer, prostate cancer, hepatocellular carcinoma (liver cancer) with infection from hepatitis C virus, acute lymphocytic non-leukemia, acute lymphocytic lymphocytic lymphocytic disease
- Nervous system diseases, such as multiple sclerosis, schizophrenia, chronic inflammatory demylinizing polyradiculoneuropathy and optic neuromyelitis.
- Inflammatory diseases.
- Infections.
- Allergies.
- Asma.
Introduction of gluten into the diet
It has currently been shown that neither early exposure to gluten nor duration of breastfeeding prevents the risk of developing celiac disease, although delayed gluten introduction is associated with delayed disease onset This contradicts the recommendations issued in 2008 by the European Society for Pediatric Gastroenterology (ESPGHAN for its acronym in English) for families of children at risk of developing celiac disease, which consisted of gradually introducing small amounts of gluten into the diet during the period between the first 4 to 7 months of life, while breastfeeding was maintained, with the hypothetical objective of teaching the immune system to tolerate gluten so that it would not mistakenly attack the body.
Risk genetics (presence of the HLA-DQ2, HLA-DQ8 haplotypes or one of their alleles) is an important factor that predicts the possibility of developing celiac disease.
High levels of non-degraded gliadin have been confirmed in breast milk (higher in colostrum) in women fed a normal diet.
Classification of cereals and seeds by their gluten content
The following chart shows which grains contain gluten and which do not. Spelled, kamut, and triticale are forms or hybrids of wheat. Flour from gluten-free grains must be certified gluten-free for consumption by people with celiac disease or those with non-celiac gluten sensitivity. It must be ground in mills independent of cereals with gluten, otherwise it would not be suitable, due to the presence of cross contamination.
| Grains with gluten | Gluten-free grains |
|---|---|
| Trigo | Trigo sarracene |
| Spelta | Sweet maize |
| Hundred | Mijo |
| Cebada | Maíz |
| Avena | Arroz |
| Kamut | Quinua |
| Triticale | Love |
| Scanda |
The main protein in rye gluten is secalin and that of barley is hordein, although both contain some gliadin. Rice itself does not contain gluten, but substances are often added when processed or refined. that contain it. Brown rice, which keeps its shell and is not processed, has no gluten residues.
Since the first decade of the XXI century, the cultivation of species rich in gluten has been promoted through hybridization, and at the same time GM crops are being investigated to produce gluten-free wheat.
Safety of oats on a gluten-free diet
The introduction of oats in the gluten-free diet is a matter of debate.
Current studies show that different varieties of oats have different degrees of toxicity for people with celiac disease or those with non-celiac gluten sensitivity.
Some varieties of pure oats (without contamination with other gluten-containing cereals) seem theoretically to have a low degree of toxicity and some experts believe that they could be included in a gluten-free diet, but it would be essential to know exactly the variety used and not there is currently no regulation in this regard. or "gluten-free oats" It does not refer to these varieties, which have not yet been identified, there have not been enough studies, nor is the long-term effect of consuming pure oats known on celiacs, so firm recommendations cannot yet be made about it. whether or not it is possible to include "pure oats" on the gluten-free diet.
Corn prolamines and their effect on celiac disease
Although corn has traditionally been considered a safe cereal in a gluten-free diet, some people with celiac disease or those sensitive to gluten may be intolerant to corn prolamins (horceins), in which case they should suppress their consumption, as can be deduced of some recent studies, carried out in Mexico in 2012.
Removing corn from the diet in some cases that do not respond to a gluten-free diet allows control of the disease, with disappearance of symptoms and recovery of damage to the intestinal mucosa.
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