A Complete Academic Breakdown of Gluten

Gluten is something all of us have heard of.

Maybe the ever-growing gluten-free section at the grocery-store has caught your eye, or you know someone who avoids it at all costs. You may have also heard about it causing fat gain, or the term being negatively associated with bread and other wheat products.

But what is it?

Is gluten really something we should all be avoiding? How much evidence is there to suggest that gluten-free diets improve our health?

In this article, we analyse what gluten is, where it is found, and whether there is any evidence to support avoiding it in our daily nutrition.

Gluten: A Common Group of Proteins

Contrary to what you might think, gluten actually refers to a group of proteins. It is an umbrella term to describe certain storage proteins contained in wheat, rye and barley. Storage proteins promote the growth and survival of the plant, with gluten serving to nourish it during its development.

Gluten is formed from two specific amino acids: Glutamine and Proline (see our article ‘Protein and Muscle Protein Synthesis Explained’ for more on amino acids).

Once a crop is harvested, it’s gluten that results in the varying textures of wheat, rye, and barley products. 

Different types of gluten have different effects. The glue-like stickiness that occurs when adding water to wheat flour, for example, is caused by Gliadins and Glutenins.

Secalin, a different type of Gluten, results in the denser structure of rye bread compared to wheat bread.

If you’ve ever tried gluten-free bread, you’ll know the difference immediately: gluten gives the fluffy, springy texture and divine taste of a freshly baked dough, something noticeably absent from its gluten-free counterpart.

The list above focuses mostly on carbohydrates as these are types of foods associated with gluten. Protein and fat based foods (meats, fish, legumes, nuts, seeds, oils etc.) are naturally gluten-free, but do be aware of any added seasoning which may contain gluten; this should be listed on the label. 

Gluten & The Digestive System

After gluten is consumed and chemically digested by our stomach, what remains enters the small intestine. 

In an optimally functioning digestive system, by the time food reaches the small intestine, it is mostly broken down into its component macronutrients (protein, fats, and carbs) and micronutrients (vitamins and minerals). These are then absorbed by the Villi and microvilli - tiny, hairlike protrusions which deliver the nutrients into the bloodstream.

The potential problem with gluten lies in the fact that Gliadins and Glutenins are tightly bound.

They don’t digest very well in the stomach, meaning that what enters the small intestine are larger peptides (strings of amino acids) — this is a mostly undigested product.

Celiac Disease

For some people the small intestine is intolerant to the presence of these large gluten peptides. People on the most serious side of the spectrum have a condition known as Celiac disease (also spelt Coeliac). It happens when gluten causes the body to attack itself with an auto-immune response. 

The villi and microvilli of the small intestine become severely damaged as a result. 

While Celiac disease can often go undiagnosed for a long period, associated symptoms include severe abdominal pain, diarrhea, and malnourishment. The pain results from the severe inflammation, while the damage to the villi and microvilli causes a significantly decreased rate of nutrient absorption.

The only proven treatment for celiac disease thus far is the complete avoidance of gluten.

The disease affects up to 1.4% of the global population. While not usually fatal, if left untreated it can result in an early death. 

Non-Celiac Gluten Sensitivity 

Non-Celiac gluten sensitivity (NCGS) is the name given to gluten-related issues that are not caused by celiac disease.

People suffering from NCGS may experience similar symptoms to those with celiac. NCGS sufferers, however, do not present with the auto-immunity associated with the latter. It is, therefore, a far less serious disorder.

Where things get a little complicated is that symptoms can be wide ranging; people might get abdominal pain or diarrhea for a wide variety of other reasons, in the same way that having anxiety or brain fog - other non-GI related symptoms of NCGS - are not necessarily related to gluten consumption.

There’s also no way to test for NCGS. Once celiac disease and wheat sensitivity have been ruled out, the advice is to simply omit gluten from the diet and see if it helps. The cause of non-celiac related gluten sensitivity remains unknown, and muddying the water further is that a growing body of research is suggesting that gluten alone isn’t the problem.

FODMAPs - Fermentable Oligosaccharides, Disaccharides, Monosaccharides, And Polyols - represent a group of carbohydrates the small intestine has trouble digesting. The grouping does encompass gluten containing foods, but research suggests that it may be FODMAPs in general which cause the symptoms associated with NCGS.

FODMAP carbs encompass wheat, rye and legumes as well as some fruits and vegetables, though this is a topic for another article. 

Then there’s irritable bowel syndrome (IBS) - a condition which may also mimic the symptoms described above, but is related to the large intestine as opposed to the small. 

As you can see, it is difficult to pin down exactly what is going on with someone experiencing these sorts of symptoms, and there is still a lot of research to be done before any concrete statements can be made regarding NCGS and other GI irritability.

Wheat Sensitivity & Wheat allergy 

Wheat can also cause GI symptoms irrespective of its ties to gluten. Cramps, bloating, and diarrhea can be caused by a sensitivity to wheat itself.

This isn’t to be confused with a wheat allergy, though. An individual with a wheat allergy displays an allergic reaction within minutes or hours of consumption of a wheat product. The immune system reaction may even cause a potentially fatal allergic reaction called anaphylaxis.

Common Myths Surrounding Gluten

Before we sum-up, let's breakdown the most common myths and misconceptions surrounding the topic of gluten. 

Gluten-free diets aid weight loss

While many gluten containing foods are high in calories such as cakes and other baked goods, there’s no evidence to suggest that omitting gluten from daily nutrition actively promotes weight loss.

This is an important distinction to make; many diets purport to aid weight loss, when in actuality, their effects can be chalked up to the basics - calories in vs calories out.

Gluten causes fatigue

Gluten consumption is commonly associated with fatigue. While fatigue is experienced in people with a gluten sensitivity, that doesn’t mean that gluten causes it in those without one.

For people without celiac disease or a sensitivity, there’s no evidence that gluten acutely causes fatigue or lack of energy.

Gluten isn’t good for you

Gluten can cause a lot of problems for some people, sure, but that doesn’t necessarily mean you should avoid it. 

It’s got a lot of bad press, but there’s nothing inherently unhealthy about gluten. Whole grains are good for you due to their high fibre content - a food-component essential for a healthy gut. If gluten isn’t causing you any issues, then there’s no logical reason to avoid it.

Should you try a gluten-free diet?

We’ve discussed above the complexities involving gluten’s potential negative effects on the body. It’s a lot to take in, encompassing many disorders that weave into one another, with mechanism still somewhat a mystery to modern science.

With symptoms overlapping, it’s difficult to know whether stomach cramps and bloating, for example, are indicative of celiac disease, NCGS, wheat sensitivity or something else entirely.

Symptoms associated with the above disorders are wide ranging. They cover a broad spectrum of both gastro-intestinal symptoms as well as those that aren't’ related to the digestive tract at all. 

Thankfully, there are a lot of great resources to help you decide whether you should get tested for celiac disease. 

Celiac.org provides a questionnaire which helps you determine if you may be at risk.

Beyond celiac is another great resource for both celiac disease and non-celiac gluten sensitivity; check out their comprehensive breakdown of NCGS here.

If Celiac, NCGS, or wheat sensitivity are found to be a problem for you, the solution for each is to omit the offending foods from your diet. If you think you may have celiac disease, though, it's important to get tested first before trying a gluten free diet.

Again, there’s no specific test for NCGS. Once other conditions have been ruled out, you’ll be required to try a gluten-free diet to see if it relieves your symptoms.

There’s nothing inherently wrong with a gluten-free or wheat-free diet, but there are a few things you should consider.

Watch what you replace gluten containing foods with. Gluten containing foods cover a pretty large group, many of which have positive health benefits like being high in fibre or providing micronutrients. 

Just be sure that if you cut bread out of your diet, for example, that you’re not skimping on your high fibre foods. Be extra vigilant regarding your consumption of fruits and vegetables to ensure you’re getting the nutrients you need.

There’s a lot we don’t know about gluten intolerance and sensitivity, and science has only scratched the surface in deciphering gluten-related disorders.

Gluten-free diets are essential for some and potentially beneficial for others. Once you’ve determined that you don’t have a disorder related to gluten, however, there’s no scientific evidence to suggest benefit in omitting it from your diet.

Linden Garcia Pepworth is a Sports Nutritionist (BSc Sports Nutrition) and YMCA Accredited Instructor. He is currently working on a review comparing the anabolic differences between plant and animal proteins.