What is Gluten and Why Would Anyone Stop Eating It?

Many people are adopting 'gluten-free' diets. STACK's Brandon Hall explores the reasons why and whether they need to.


That word is flying around in conversation much more than it was a decade ago. You've probably heard about certain people trying to cut gluten out of their diet. Many who have tried gluten-free diets have reported positive results, such as increased energy and improved body composition.



That word is flying around in conversation much more than it was a decade ago. You've probably heard about certain people trying to cut gluten out of their diet. Many who have tried gluten-free diets have reported positive results, such as increased energy and improved body composition.

Some professional athletes—like Mark Teixeira and Stephen Jackson—have adopted gluten-free diets in the belief that it will help them feel and play better. But why? What exactly is gluten, and what are people trying to gain by giving it up? Here's everything you need to know about gluten.

What is Gluten?

What is Gluten?

Gluten is a naturally occurring protein found in cereal grains. It's a composite of two sub-proteins—gliadin and glutenin.

The function of gluten is to help foods maintain their shape and hold everything together. When you see a chef tossing pizza dough around, the dough can stretch and change shape with elasticity without falling apart because of gluten. Gluten basically acts as the "glue" that holds food together.

Where is Gluten Found?

Where is Gluten Found?

Gluten is found in cereal grains. The big three gluten-containing grains are wheat, barley and rye. Triticale, a rye-wheat hybrid grain, also contains gluten. People have been eating gluten for thousands of years, since barley, rye and especially wheat have been used in food products for a very long time.

RELATED: The Grain Guide: How and Why to Use 8 Healthy Whole Grains

Of course, gluten still plays a big role in our food. Any product that contains those grains contains gluten.

Since innumerable products are made with those grains, gluten can be almost anywhere. The Celiac Disease Foundation publishes a long list of products that contain gluten. It may not surprise you that breads, pastas, crackers, cereals, beer and tortillas contain gluten, but what about other sources of gluten such as soups, salad dressings, lunch meats, potato chips, vitamins and even play-dough?

Some of those products might contain just a trace of gluten, but that can be a big deal for an individual who suffers from celiac disease.

What is Celiac Disease?

What is Celiac Disease?

According to the Celiac Disease Foundation, celiac disease is "an autoimmune disorder that can occur in genetically predisposed people where the ingestion of gluten leads to damage in the small intestine."

When someone with celiac disease eats gluten, "their body mounts an immune response that attacks the small intestine." This attack damages the villi, small projections lining the inside of the small intestine that promote nutrient absorption. When the villi get damaged, nutrients cannot be properly absorbed into the body.

Although celiac disease is hereditary, it can develop at any age. Short-term symptoms include diarrhea, abdominal pain, excessive gas, irritability, difficulty focusing and fatigue. If celiac disease is left untreated, it can lead to more serious conditions, such as multiple sclerosis, diabetes, anemia, infertility, epilepsy and intestinal cancers.

The only known current treatment for celiac disease is strict adherence to a gluten-free diet.

RELATED: How Athletes with Celiac Disease Can Eat Healthy and Stay Gluten-Free

Celiac disease affects roughly one percent of Americans. But it certainly feels like a lot more people than that are trying to avoid gluten, right? They certainly are, and it's likely because many of them believe they suffer from gluten sensitivity.

What is Gluten Sensitivity?

What is Gluten Sensitivity?

According to the Celiac Disease Foundation, gluten sensitivity is "a condition with symptoms similar to those of celiac disease that improve when gluten is eliminated from the diet."

These symptoms include bloating, abdominal pain, diarrhea, headaches, bone or joint pain, depression and fatigue. Individuals with gluten sensitivity do not test positive for celiac disease, and they don't suffer small intestine damage like those with celiac disease do when they consume gluten.

Like celiac disease, the only known treatment for gluten sensitivity is adherence to a gluten-free diet.

To be diagnosed with gluten sensitivity, you must first find out if you have celiac disease (or possibly wheat allergy, a much rarer condition). This typically involves a blood test followed by an endoscopic biopsy. If the biopsy comes back negative for celiac disease, you must then begin a gluten-free diet. If you feel better after an extended period of following a gluten-free diet, you must then return gluten back into your diet to confirm that gluten consumption is indeed the cause of your symptoms.

That's a lot to go through for a diagnosis.

According to the National Foundation for Celiac Awareness, roughly 18 million Americans suffer from gluten sensitivity—approximately 6 percent of the population. But even when you combine that number with the number of people who suffer from celiac disease, you only get 7 percent of all Americans. Again, doesn't that number seem low compared to the growing popularity of the "gluten-free" lifestyle?

There's a reason for that. Most people who think they have gluten sensitivity probably do not—at least not medically speaking. However, getting an official diagnosis is so cumbersome that many people are unlikely to go through the process, leaving them believing they really do have gluten sensitivity.

Not Everyone Has Gluten Sensitivity

Not Everyone Has Gluten Sensitivity

A recent study published in the journal Digestion took a look at 392 patients who were complaining of gluten-related symptoms. The participants perceived their symptoms as being caused by gluten sensitivity.

The aim of the study was to determine how many people who believe they suffer from gluten sensitivity are correct in their self-diagnosis.

Initially, patients were tested for celiac disease and wheat allergy to rule those conditions out.

Participants who had neither celiac disease nor wheat allergy were tested for non-celiac gluten sensitivity (NCGS). To confirm a diagnosis of NCGS, their symptoms had to disappear within 6 months of starting a gluten-free diet and  subsequently reappear when gluten was reintroduced into their diet for 1 month.

The study found that of the 392 patients who believed their symptoms were related to gluten, 26 of them (6.63%) had celiac disease, two of them (.51%) had a wheat allergy and 27 of them (6.88%) had NGCS. So out of 392 patients who believed they were sensitive to gluten, 86% could tolerate it without adverse affects.

The study concluded that "self-perceived gluten-related symptoms are rarely indicative of the presence of NCGS (non-celiac gluten sensitivity)."

RELATED: 4 Nutrition Myths Demystified


A lot of people who think they're sensitive to gluten might not be. This has been the source of much recent controversy. Most people who think they are sensitive to gluten really do feel better when they get off it. There's a chance that these people have celiac disease or a legitimate gluten sensitivity, but there's a greater chance that their improvements might be due to the nature of a gluten-free diet.

The "Benefits" of Going Gluten-Free

For many people, feeling better when they switch to a gluten-free diet might have nothing to do with gluten.

Many highly processed foods contain gluten—such as candies, cookies, cakes, pies, processed lunch meats and seasoned snack foods. "Highly processed foods typically have fewer vitamins, minerals, phytochemicals, antioxidants, and nutrients like fiber and protein than lower processed foods. They also usually contain more low-quality fat, sugar, sodium, calories and refined carbohydrates," says Brian St. Pierre, a nutrition coach at Precision Nutrition.

Highly processed foods play a major role in the average American diet—making up 61% of our daily calories.

RELATED: New Study Says Half your Daily Calories Come from Highly Processed Foods

Since many highly-processed foods contain gluten, they would be cut out of a gluten-free diet, replaced by gluten-free foods such as fruits and vegetables, fresh meat and fish (un-breaded), beans, legumes, nuts, seeds and fresh eggs. Eating more of these healthier foods instead of highly processed foods could be one big reason why someone feels better on a gluten-free diet (regardless of whether they're actually sensitive to gluten).

On the Cleveland Clinic's official website, STACK Expert Kristin Kirkpatrick, registered dietitian, writes, "Eating gluten-free often may cause you to eat more whole, unprocessed foods such as fruits, vegetables, legumes and lean meats. These diet changes are often healthier and lower in calories. People eating gluten-free also tend to make healthier food choices because they are more aware of the need to read food labels."

This type of nutritional behavior will help anyone feel better in a multitude of ways. Since the gluten-free diet is helping many people feel (and often look) better, it's becoming more trendy and more popular. The gluten-free food industry is booming, experiencing an average 34 percent increase in sales in each of the last five years. By 2019, total sales of gluten-free products are expected to reach $2.34 billion. Most gluten-free products are more expensive than their gluten-containing alternatives, but hordes of customers are happily plopping down money in the belief that it will pay off with better health and wellness.

However, there seems to be little evidence that removing gluten from your diet will improve your health if you don't suffer from a legitimate gluten sensitivity.

According to The University of Chicago Celiac Disease Center, "although popular culture promotes a gluten-free diet as a healthier way to eat, there is no scientific evidence that proves such a claim to be true. In fact, studies have shown the risk of essential nutrient deficiency in those that do not have a medical reason for following a gluten-free diet."

According to the Harvard Medical School, people on a gluten-free diet could be at risk of deficiencies in B vitamins and fiber. But taking a varied approach that includes lots of fruits, veggies and legumes can help avoid such deficiencies.

The Verdict

Gluten Free

A small percentage of population benefit biologically by cutting all gluten out of their diets—people with celiac disease and gluten sensitivity. For  everyone else who claim that abolishing gluten turned their life around, it was probably a combination of other factors. New research could prove that everyone would be better off by giving up gluten, but for now the best approach is to eat more natural, plant-based foods, pay attention to nutrition labels and exercise regularly.

If you want to try going gluten-free—even if you don't believe you suffer from celiac disease or diagnosable gluten sensitivity—you can. The only real risk is nutrient deficiencies, which can be avoided with a varied diet. Giving up gluten is not necessary to live a healthier life, and it can often make eating more of a burden, but the discipline has helped some people achieve their eating goals.

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