Is Gluten Bad for You? A Critical Look

A gluten-free diet is necessary for celiac disease, wheat intolerance, or non-celiac gluten sensitivity. Autoimmune and digestive conditions may also benefit. Research isn’t conclusive about the general health benefits of it.

Going gluten-free may be the biggest health trend of the past decade, but there’s confusion over whether gluten is problematic for everyone or just those with certain medical conditions.

It’s clear that some people must avoid it for health reasons, such as those with celiac disease or an intolerance.

However, many in the health and wellness world suggest that everyone should follow a gluten-free diet — regardless of whether they’re intolerant or not.

This has led millions of people to give up gluten in hopes of losing weight, improving mood, and getting healthier.

Still, you may wonder whether these methods are backed by science.

This article tells you whether gluten really is bad for you.

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What Is Gluten?

Though often thought of as a single compound, gluten is a collective term that refers to many different types of proteins (prolamins) found in wheat, barley, rye, and triticale (a cross between wheat and rye) (1).

Various prolamins exist, but all are related and have similar structures and properties. The main prolamins in wheat include gliadin and glutenin, while the primary one in barley is hordein (2).

Gluten proteins — such as glutenin and gliadin — are highly elastic, which is why gluten-containing grains are suited for making bread and other baked goods.

In fact, extra gluten in the form of a powdered product called vital wheat gluten is often added to baked goods to increase the strength, rise, and shelf life of the finished product.

Gluten-containing grains and foods make up a large portion of modern-day diets, with estimated intake in Western diets around 5–20 grams per day (1).

Gluten proteins are highly resistant to protease enzymes that break down proteins in your digestive tract.

The incomplete digestion of proteins allows for peptides — large units of amino acids, which are the building blocks of proteins — to cross over through the wall of your small intestine into the rest of your body.

This can trigger immune responses that have been indicated in a number of gluten-related conditions, such as celiac disease (3).

Gluten is an umbrella term that refers to a family of proteins known as prolamins. These proteins are resistant to human digestion.

Gluten Intolerance

The term gluten intolerance refers to three types of conditions (4).

Although the following conditions do have some similarities, they differ greatly in terms of origin, development, and severity.

Celiac Disease

Celiac disease is an inflammatory autoimmune disease caused by both genetic and environmental factors. It impacts around 1% of the world’s population.

However, in countries like Finland, Mexico, and specific populations in North Africa, the prevalence is estimated to be much higher — about 2–5% (5, 6).

It’s a chronic condition associated with the consumption of gluten-containing grains in susceptible people. Though celiac disease involves many systems in your body, it’s considered an inflammatory disorder of the small intestine.

The ingestion of these grains in those with celiac disease causes damage to enterocytes, which are cells lining your small intestine. This leads to intestinal damage, nutrient malabsorption, and symptoms like weight loss and diarrhea (7).

Other symptoms or presentations of celiac disease include anemia, osteoporosis, neurological disorders, and skin diseases, such as dermatitis. Still, many people with celiac disease may have no symptoms at all (8, 9).

The condition is diagnosed by intestinal biopsy — considered the “gold standard” for diagnosing celiac disease — or blood testing for specific genotypes or antibodies. Currently, the only cure for the disease is total avoidance of gluten (9).

Wheat Allergy

Wheat allergy is more common in children but can impact adults as well. Those who are allergic to wheat have an abnormal immune response to specific proteins in wheat and wheat products (4).

Symptoms can range from mild nausea to severe, life-threatening anaphylaxis — an allergic reaction that can cause difficulty breathing — after ingesting wheat or inhaling wheat flour.

Wheat allergy is different from celiac disease, and it’s possible to have both conditions.

Wheat allergies are usually diagnosed by allergists using blood or skin-prick testing.

Non-Celiac Gluten Sensitivity

A large population of people reports symptoms after eating gluten, even though they don’t have celiac disease or an allergy to wheat (10).

Non-celiac gluten sensitivity (NCGS) is diagnosed when a person does not have either of the above conditions yet still experiences intestinal symptoms and other symptoms — such as headache, fatigue, and joint pain — when they consume gluten (11).

Celiac disease and wheat allergy must be ruled out to diagnose NCGS since symptoms overlap in all of these conditions.

Like those with celiac disease or an allergy to wheat, people with NCGS report improvement of symptoms when following a gluten-free diet.

Gluten intolerance refers to celiac disease, wheat allergy, and NCGS. Although some symptoms overlap, these conditions have significant differences.

Other Populations That May Benefit From a Gluten-Free Diet

Research has shown that following a gluten-free diet is effective in reducing symptoms related to several conditions. Some experts have linked it to the prevention of certain diseases as well.

Autoimmune Disease

There are several theories as to why gluten may cause or worsen autoimmune conditions, such as Hashimoto’s thyroiditis, type 1 diabetes, Grave’s disease, and rheumatoid arthritis.

Research shows that autoimmune diseases share common genes and immune pathways with celiac disease.

Molecular mimicry is a mechanism that has been suggested as a way in which gluten initiates or worsens autoimmune disease. This is when a foreign antigen — a substance that promotes an immune response — shares similarities with your body’s antigens (12).

Eating foods that contain these similar antigens can lead to the production of antibodies that react with both the ingested antigen and your body’s own tissues (13).

In fact, celiac disease is associated with a higher risk of having additional autoimmune diseases and is more prevalent in people with other autoimmune conditions (14).

For example, the prevalence of celiac disease is estimated to be up to four times higher in those with Hashimoto’s thyroiditis — an autoimmune thyroid condition — than in the general public (15).

Therefore, numerous studies find that a gluten-free diet benefits many people with autoimmune diseases (16).

Other Conditions

Gluten has also been tied to bowel diseases, such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis (17).

Plus, it’s been shown to alter gut bacteria and increase intestinal permeability in people with IBD and IBS (18).

Lastly, research indicates that gluten-free diets benefit people with other conditions, such as fibromyalgia, endometriosis, and schizophrenia (2).

Many studies link gluten to the initiation and progression of autoimmune diseases and show that avoiding it may benefit other conditions, including IBD and IBS.

Should Everyone Avoid Gluten?

It’s clear that many people, such as those with celiac disease, NCGS, and autoimmune diseases, benefit from following a gluten-free diet.

Nevertheless, it’s unclear whether everyone — regardless of health status — should change their eating habits.

Several theories have developed as to why human bodies may not be able to handle gluten. Some research suggests that human digestive systems have not evolved to digest the kind or amount of grain proteins that are common in modern diets.

Plus, some studies show a possible role in other wheat proteins, such as FODMAPs (specific types of carbs), amylase trypsin inhibitors, and wheat germ agglutinins, in contributing to symptoms related to NCGS.

This suggests a more complicated biological response to wheat (19).

The number of people who avoid gluten has risen dramatically. For example, U.S. data from the National Health and Nutrition Examination Survey (NHANES) shows that the prevalence of avoidance more than tripled from 2009 to 2014 (2).

In people with reported NCGS who undergo controlled testing, the diagnosis is confirmed in only approximately 16–30% (20, 21).

Still, since the reasons behind NCGS symptoms are largely unknown and testing for NCGS has not yet been perfected, the number of people who may react negatively to gluten remains unknown (22).

While there is an obvious push in the health and wellness world to avoid gluten for overall health — which impacts the popularity of gluten-free diets — there’s also increasing evidence that the prevalence of NCGS is on the rise.

Currently, the only way to know if you would personally benefit from a gluten-free diet after ruling out celiac disease and wheat allergy is to avoid gluten and monitor your symptoms.

Currently, reliable testing for NCGS is unavailable. The only way to see if you would benefit from a gluten-free diet is to avoid gluten and monitor your symptoms.

Why Many People Feel Better

There are several reasons why most people feel better on a gluten-free diet.

First, avoiding gluten usually involves cutting back on processed foods, as it’s found in a wide array of highly processed foods, such as fast food, baked goods, and sugary cereals.

These foods not only contain gluten but are typically also high in calories, sugar, and unhealthy fats.

Many people say that they lose weight, feel less fatigued, and have less joint pain on a gluten-free diet. It’s likely that these benefits are attributed to the exclusion of unhealthy foods.

For example, diets high in refined carbs and sugars have been linked to weight gain, fatigue, joint pain, poor mood, and digestive issues — all symptoms related to NCGS (23, 24, 25, 26).

What’s more, people often replace gluten-containing foods with healthier options, such as vegetables, fruits, healthy fats, and proteins — which can promote health and well-being.

Additionally, digestive symptoms may improve as a result of reducing intake of other common ingredients, such as FODMAPs (carbs that commonly cause digestive issues like bloating and gas) (27).

Although improved symptoms on a gluten-free diet may be related to NCGS, these improvements could also be due to the reasons listed above or a combination of the two.

Cutting out gluten-containing foods may improve health for several reasons, some of which may be unrelated to gluten.

Is This Diet Safe?

Though many health professionals suggest otherwise, it’s safe to follow a gluten-free diet — even for people who don’t necessarily need to do so.

Cutting out wheat and other gluten-containing grains or products will not cause adverse health effects — as long as these products are replaced with nutritious foods.

All of the nutrients in gluten-containing grains, such as B vitamins, fiber, zinc, iron, and potassium, can easily be replaced by following a well-rounded, whole-foods-based diet consisting of vegetables, fruits, healthy fats, and nutritious protein sources.

Are Gluten-Free Products Healthier?

It’s important to note that just because an item is gluten-free doesn’t mean that it’s healthy.

Many companies market gluten-free cookies, cakes, and other highly processed foods as healthier than their gluten-containing counterparts.

In fact, one study found that 65% of Americans believe gluten-free foods are healthier, and 27% choose to eat them to promote weight loss (28).

Although gluten-free products are proven to be beneficial for those who need them, they’re not any healthier than those that contain gluten.

And while following a gluten-free diet is safe, keep in mind that any diet that relies heavily on processed foods is unlikely to result in any health benefits.

Plus, it’s still debated whether adopting this diet benefits the health of those without an intolerance.

As research in this area evolves, it’s likely that the relationship between gluten and its impact on overall health will be better understood. Until then, only you can decide whether avoiding it is beneficial for your personal needs.

While it’s safe to follow a gluten-free diet, it’s important to know that processed gluten-free products are not any healthier than gluten-containing ones.

The Bottom Line

Following a gluten-free diet is a necessity for some and a choice for others.

The relationship between gluten and overall health is complicated, and research is ongoing.

Gluten has been linked to autoimmune, digestive, and other health conditions. While people with these disorders must or should avoid gluten, it’s still unclear whether a gluten-free diet benefits those without an intolerance.

Since currently there’s no accurate testing for intolerance and avoiding gluten poses no health risks, you can try it to see whether it makes you feel better.