The gluten-free lifestyle is on the rise but scientists say don’t bite that FUD

After several years since gluten-free became the trendy diet, it continues to get adepts and the number of products available for them is on the increase. In spite of this, scientific studies don’t support any health benefits for those without sensitivity.

Photo via Max Pixel (CC0) illustrated by Author

With only 0.7 % of the population affected by celiac disease and up to 13% by non-celiac gluten sensitivity (NCGS), one-third of American adults avoid gluten as part of a healthy lifestyle. As opposed to those who present gluten as a dietary enemy, others just see a fad in their phobia. The latter argue that humans have been eating gluten for thousands of years and that just recently it has been demonized as a health risk. Looking at the scientific data so far, they may be right — at least in part.

Gluten is a set of proteins present in some cereals, consisting mainly of prolamins and glutenins. When mixing the flour with water, prolamins — which in the case of wheat are called gliadins — give the dough the properties of slime — viscosity and extensibility — while glutenins make it behave like chewing gum, adding elasticity and strength. The variety of the cereal, the technological processes to which it is subjected as well as the growing conditions of the plant, determine the amount of gluten, its composition — size of gliadins and glutenins, type, ratio — and structure — how they are linked together — what ultimately define the properties of the dough. Depending on the food product different gluten characteristics are needed. For example, for bread-making, the dough should have a balance of extensibility and strength, to trap the gas produced in the fermentation without tearing up, and be elastic, to form the desired shape. Whereas dough for pasta should be elastic and strong to keep its structure after cooking and not become a sticky mess.

Food containing gluten — such as bread and pasta — not only has been in our diet throughout the ages but it has also been a major source of daily energy requirements, without causing any damage. The question about its health implications might be on how different today’s gluten is from the one our ancestor ate. It especially changed with the 1960s green revolution. The agricultural industry selected more productive cereal varieties and with the gluten characteristics that the food industry demanded, affecting its quality rather than its quantity, and, as a consequence, its digestibility — responsible for most health problems associated with gluten intake. For example, the wheat varieties selected to produce bread of higher quality, contain a gluten network hard to break down by humans’ digestive system. The incomplete digestion of gluten in the stomach generates oligopeptides — small chains of peptides produced from the metabolism of proteins — that remain in the lumen of the small intestine. Some of them are responsible for the development of the inflammatory process associated with celiac disease.

Dr Fardet, a researcher at the National Institute of Agricultural Research (INRA), in France, points out two additional reasons to explain why gluten has become so harmful for some: the large quantities we ingest and the technological processes to which cereals and gluten are subjected.

The amount of gluten we eat has increased not only due to the introduction of many foods that contain cereals, but because it is used as an additive to many processed foods. In particular, a frequent practice in the preparation of bread is to add extra gluten — known as “vital gluten” in the trade — to the flour. For example, it is added to those with higher fiber content to improve their bread-making characteristics. But bread is not the only product where gluten is added. Its stability at high temperatures, extensible properties and ability to act as a binding agent, make it an ideal additive for food that is not easily associated with sources of gluten. Ice cream, butter, sauces, processed meats, and vegetarian meat substitutes are some examples of them.

Regarding the processing of cereals, a usual practice consists on the one hand to refine them, and on the other to add the necessary ingredients to obtain the desired results, which usually does not provide a health benefit but the opposite. With the refining of cereals, fiber, as well as antioxidant and anti-inflammatory compounds, are eliminated. This fact, together with the addition of ingredients — such as sugars, fats, and salts — can induce the appearance of inflammatory processes, a cause that underlies many chronic diseases.

The current bread-making process also plays a fundamental role. Specifically, the replacement of sourdough by yeasts has allowed producing bread more quickly but leading to gluten more difficult to metabolize. This is because of two reasons. The proteases — enzymes that help to break down proteins — contained in the sourdough are eliminated and the yeasts generate gluten almost intact. As if this was not enough, the extra gluten added to many products is more difficult to digest than that found naturally in the cereal because it lacks the enzymes that wheat contains for the degradation of gliadins.

In spite of the changes that gluten has undergone not all of us have the same chances to be celiac or NCGS, genetic predisposition and feeding play a very important role. Those affected by these diseases have to avoid gluten, however, some lifestyle gurus promote it also to cure a range of health issues. Even for some athletes not eating gluten is the way to increase sports performance, such top one tennis player Novak Djokovic, who believes that be under a gluten-free diet is the secret of his success in the grass game. Unlike him, Roger Federer, arguably the best tennis player of all time, eats a plate of pasta before every match. This controversy is found even among nutritionists and medical doctors. The truth is, that none of the clinical trials carried out so far justify a clear benefit of a gluten-free diet for any health condition out of celiac or NCGS. Neither it has been demonstrated that it improves the sports performance.

The question for those who don’t eat gluten without a medical condition that forces them to do it is what they eat instead. The reason why they feel better might be in the substitution of food containing gluten — highly processed in some cases — by fruits, vegetables, and gluten-free whole grains.

The good news, based on what we know today, is that if you are a gluten lover you don’t need to quit on it. Just stay away from processed food as much as possible, and when craving a sandwich, pasta or any other food containing gluten make sure that your suppliers work with whole grains, use sourdough as starters and don’t add vital gluten. Of course, the safest option is to make it from scratch.

PhD in Food Science & Nutrition, Gema has published over 60 scientific papers and is a former researcher at Columbia, Reading, CUNY, and the CSIC

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