If you put a piece of raw bread dough in your mouth and chew it slowly, you will notice how it acquires consistency until it reaches an elasticity similar to that of chewing gum. It is because wheat flour , the most consumed cereal in the world, contains gluten , or what the Chinese very graphically nickname as flour muscle . This component consists, above all, of gliadins and glutenins, the largest protein molecules in nature . They are the ones who are in charge of maintaining a certain tension in the loaves, as do the muscle fibers of our arms. While they are dry inside the flour sack, both proteins remain immobile, but as soon as they are moistened with water, the dance begins : they move, change shape, come closer to each other, establish links between them and, finally, they are arranged forming a spiral with many turns. If the dough is stretched, these curves straighten, and if it relaxes, the spirals re-form and the raw material shrinks .
Although bakers handle the chemistry of gluten with absolute naturalness in their bakeries on a daily basis, if we stop to analyze it thoroughly, it must be recognized that it is out of the ordinary. On the one hand, the yeasts in bread generate gas – carbon dioxide – from the fermentation of sugars , and the dough expands like a balloon. But simultaneously, our protagonist forms a mesh with the necessary resistance so that the walls of the internal bubbles never break. Thus, when the loaf or bakery products are baked , the puffed gluten dries and forms a structure that is flexible and consistent at the same time, leaving multiple voids inside.
Mindless reaction
In short, that we can enjoy a tender porous crumb or a fluffy and light bun is possible thanks to the singularities of this molecule, which has made human beings tireless panivores for at least the last 10,000 years of history. However, it should be remembered that not everyone can take a bite out of toast or traditional pizza. The immune system of those affected by the so-called celiac disease – one in a hundred people suffers it, approximately – considers gluten as a very dangerous foreign body that must be defended with nails and teeth. This defensive error leads to an aggressive reaction in the small intestine that inflames and destroys the digestive epithelium after eating bread, pasta or cookies. The immediate consequence is that the finger-shaped villi that cover the intestinal mucosa , called enterocytes, atrophy.
With such damage, it is impossible to adequately absorb nutrients from food. Since there is currently no treatment for this intolerance , the only way to avoid anemia, chronic diarrhea, severe osteoporosis, or the delayed growth it brings is to follow a strict , gluten-free diet for life . That means giving up all food that contains four types of grain: wheat, rye, barley and oats . Hybrids or derivatives thereof, such as kamet, spelled and triticale, are also prohibited. The concern of health experts about celiac disease is more than understandable if we consider that there are currently four times more affected than fifty years ago, as revealed by the US Mayo Clinic in a study published by the journal Gastroenterology . “Something has changed in our environment that makes the disease more common,” warns gastroenterologist Joseph Murray, co-author of the research, although at the moment he admits not knowing what that change lies in.
A telltale protein
According to a study by the Swedish universities of Umea and Uppsala, the explanation could be found in the –bad– health of babies. Their data indicates that suffering three or more infections during the first six months of life would increase the chances of being celiac by no less than 50%. And when the condition that recurs over and over again is gastroenteritis , the probability skyrockets to 80%. The research also revealed that if breastfeeding is stopped early , before gluten is introduced into the child’s diet, the danger of intolerance reappears.
In Finland, scientists have tightened their grip on viruses. According to studies of the DNA of patients, the genes that predispose to developing celiac disease are related to the defenses of the immune system against the invasion of these pathogens. “This raises the suspicion that viral infections are somehow connected with gluten intolerance ,” says Päivi Saavalainen, co-author of the research.
In any case, the genetics related to celiac disease is more complex than it seems, as shown by a multidisciplinary research aimed at reconstructing the history of the evolution of Europeans, and in which Spanish experts have participated. “A series of genes have been detected that increase the risk of contracting the disease: some belong to the autoimmune system and others, like those we found in our prehistoric selection study, are more related to the prevention of vitamin deficiencies – specifically, ergothionein– in diets almost exclusively based on cereals ”, points out Carles Lalueza-Fox, researcher at the Paleogenomics Laboratory of the Institute of Evolutionary Biology, in Barcelona.
These genes are two and are called SLC22A4 and ATXN2 / SH2B3. Everything points to the fact that they arose to protect us from the vitamin deficiency derived from the transition from a highly protein diet – that of the Mesolithic – to a more agricultural one , the one we adopted from the Neolithic, about 10,500 years ago. The problem is that, secondarily, some of the variants of this pair of genes predispose to celiac disease. “They would be beneficial for the survival of Neolithic populations, but nowadays, when our diets are no longer so based on cereals, they have become a disadvantage”, clarifies Lalueza-Fox.
Diagnosing whether or not a person is celiac is another of the headaches for today’s medicine. In fact, as Murray emphasizes, “some studies suggest that for every person diagnosed there are no less than thirty who suffer it without knowing it .” And since mortality from silent celiac disease has also quadrupled, it is urgent to take the problem seriously.
A recent work by the Human and Animal Molecular Genetics group of the University of Jaén could contribute to dispel the doubts, which has unmasked the involvement of a molecule of our defensive system, interleukin-33, in the inflammatory process that occurs in the celiacs when ingesting gluten. The mission of this protein is to regulate possible errors in the activation or proliferation of immune cells, which makes it a good candidate to become a precise marker of the disease, according to experts. “Today, many doctors have trouble differentiating celiac disease from other inflammatory bowel diseases, such as irritable bowel syndrome. The aforementioned interleukin could come to their aid, because if a patient presents it at high levels, it could put the doctor on the track of the disease “, underlines Maribel Torres, head of the investigation.
An indoor pharmacy
Another hopeful news for those affected is that their gluten-free diet could have its days numbered if research such as that carried out by Thomas JD Jørgensen and his colleagues at the University of Southern Denmark is successful. Like many other scientists, they also do not give up their efforts to find an effective drug to cure this intolerance . To do this, they look for clues that help them understand the reaction of the antibodies produced by the celiac defense system in contact with the tissue transglutaminase enzyme (tTG), to which they direct their friendly fire attack.
If the activity or structure of tTG could be modified, the medicine could prevent the destructive autoimmune reaction. Another study from the University Hospital of Tampere, in Finland, focuses its hopes on the enzyme ALV003, which if ingested with food reduces exposure to gluten. Taking a KumaMax pill would have a better chance of success. This is how a modified enzyme has been named that, according to scientists at the Howard Hughes Medical Institute in the United States, is capable of shattering practically 100% of the proteins that cause the immune reaction, even in conditions of extreme acidity of the stomach . The defenses would thus have no target to attack and the symptoms would disappear at a stroke, even if the patient had a hypothetical oatmeal sandwich for lunch accompanied by a refreshing beer brimming with barley.
For their part, French experts from the National Institute for Agronomic Research (INRA) and the National Institute of Health (INSERM) are betting on elafin , a protein with anti-inflammatory properties that is less abundant in celiacs than in healthy people. This molecule prevents the destruction of the digestive system and interacts with enzymes linked to autoimmune disease. In other words, a shot of elafin would reduce the toxicity of gluten. Instead of prescribing it to be ingested orally, the researchers are opting to administer a harmless lactic acid bacteria that is usually present in food: Lactococcus lactis . This would be modified to manufacture the antidote within the digestive system in industrial quantities. INRA has already patented such a promising therapeutic strategy in this line.
Until these initiatives are successful, chronic intolerant sufferers have no choice but to continue restricting their diet to gluten-free foods. But what if you are not celiac? Is it healthier to avoid the protein molecule, an idea popularized by celebrities like Lady Gaga, Victoria Beckham and Novak Djokovic? Most experts say no. Despite the recent trend to view gluten as one of the nutrition villains, the truth is that there is no scientific proof that it is harmful to health. On the contrary: we know that whole grains such as wheat are a recommended source of fiber, vitamins, iron, calcium, folic acid and several minerals .
Taking into account that this cereal has been part of the Mediterranean diet since time immemorial, and that it has been shown that this dietary pattern lengthens life, helps prevent cancer and reduces the risk of suffering from cardiovascular diseases, give it up without suffering problems of intolerance does not seem the most sensible thing to do. This is how Marta Cuervo, a nutritionist at the University of Navarra, maintains it. According to this expert, “possibly we are facing one more miracle diet. It will take a while and other types of food trends will appear that will unseat her. I do not see the point of demonizing gluten in people who do not suffer from celiac disease, nor do I see the point in avoiding lactose if we digest it perfectly ”, concludes Dr. Cuervo.
