Is gluten bad for you?

For individuals with the right (or wrong) mix of genetic, diet and microbiome characteristics, gluten can be toxic — but for the rest of us, rice and granola aren’t the enemy.

Have you ever wondered why Betty Crocker sells gluten-free versions of your favorite flavor of boxed cake mix? Is it because Madonna and tennis star Djokovic went gluten-free that your favorite grocery store now has a whole aisle dedicated to gluten-free everything? While celebrities and top athletes do influence mainstream attitudes toward health trends, there are certain groups of people (mainly those with medical conditions such as celiac disease, wheat allergy or non-celiac gluten sensitivity) that do react badly to gluten and experience a higher quality of life when they avoid it. So what is gluten, and is gluten bad for you? If people with certain diseases do better without it, couldn’t everyone experience better health without it? Or could eliminating gluten actually be dangerous for you? We’ll answer these questions and more. 

What is gluten?

Gluten is a peptide macromolecule found in grains such as wheat. This macromolecule, in the plant’s natural state, provides the plant with structure and rigidity. In the production of food, gluten also provides important structural properties. Gluten provides bread dough elasticity, a feature that is required to produce bread with the taste and texture normally expected by a consumer.

Common sources of gluten include:

  • Wheat
  • Barley
  • Rye 
  • Triticale 
  • Malt
  • Brewer’s yeast
  • Wheat starch 
  • Wheat derivatives like semolina and durum

Gluten is made up of various sized versions of two types of proteins called gliadins and glutenins. These proteins are made up of a large number of the amino acids proline and glutamine, and are collectively referred to as prolamins. Accumulation of prolamins in the gastrointestinal (GI) tract compromises the intestinal epithelial barrier via various mechanisms, which can lead to inflammation and the onset of certain GI diseases — particularly in people who are genetically at risk. Studies have shown that breaking down prolamins through oral treatments can actually relieve disease symptoms, emphasizing the role that gluten plays in these cases.  

Can gluten make you sick?

The consumption of gluten and wheat products are overarching risk factors for many GI diseases. Usually, disease onset results from a complex interplay between diet, the gut microbiome and genetic risk factors. The genetic factors that are associated with these types of diseases are involved in eliciting a hyperactive immune response against gluten proteins or in reducing the body’s ability to break down gluten. There are three main GI conditions associated with gluten consumption:

  • Celiac disease (CD) is a multifactorial disease characterized by chronic intestinal inflammation in response to gluten consumption, causing symptoms such as bloating, diarrhea and gas. People who suffer from CD have genetic mutations in genes that cause a hypersensitive response to gluten and transglutaminase, the enzyme that breaks down prolamine proteins. About 30-40% of the population have the genes associated with CD, but only about 1% actually get CD — suggesting that other genetic factors and diet play a role in development of the disease.

  • Wheat allergy is often confused with CD but is a different condition, as the allergy is not specific to gluten but rather to wheat proteins in general. Symptoms typical of this condition include swelling or itchiness of the throat, hives, nasal congestion, difficulty breathing, GI symptoms and anaphylaxis. Development of this disease is caused by the activation of helper T cells — a type of immune cell in your body — which causes your body to have an immune response to wheat. Immune cells then infiltrate the GI tract, causing inflammation and the destruction of GI tissue. 
  • Non-celiac gluten sensitivity (NCGS) is a disease with symptoms and pathology similar to those found in CD and wheat allergy, but without any of the genetic predispositions associated with those diseases. The common thread between the group of diseases is the association with the consumption of wheat products. NCGS has also been linked to non-wheat food products containing milk proteins, lactose and fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs). 

The microbiome and gluten

While genetics can play an important role in the development of gluten-related diseases such as CD, evidence points to a role for the microbiome as well. In fact, many of the genetic factors that put an individual at risk for CD also disrupt the intestinal environment in a way that can impact the balance of the microbes that live there. Several studies have shown that such an imbalance — called microbiome dysbiosis — is a condition that by itself can disrupt GI tissue and contribute to disease. The impact that the GI microbiome has on the development of CD is an important topic of ongoing investigation. Studies examining the dynamics between diet, the GI microbiome and gluten-associated disease describe an interdependence between each factor:

  • Bioaccumulation of prolamins in the gut cause gluten toxicity.  
  • The presence of gluten initiates an immune response that leads to inflammation. 
  • Inflammation restructures the intestinal lumen-epithelial environment and promotes the loss of healthy bacterial species and the enrichment of species that induce inflammation. 
  • A gluten-free diet (GFD) reduces the presence of prolamins.
  • Reductions in prolamins in the gut are sufficient to reduce or eliminate GI symptoms and the restoration of a GI microbiome that promotes health. 

Can eliminating gluten improve health?

Diet and the microbiome play a critical role in the progression, prevention and treatment of gluten-associated symptoms and disease. People diagnosed with CD typically follow diets restricted in the consumption of foods made from grain. In fact, a gluten-free diet (GFD) is a necessary intervention for people who suffer from CD. Continued gluten consumption by individuals with CD leads to long-term chronic GI tissue inflammation and increased risk for the development of other diseases such as small intestinal adenocarcinoma, esophageal cancer, melanoma and non-Hodgkin’s lymphoma. The development of processed gluten-free foods and clear labeling of naturally gluten-free foods is expanding the dietary options and ease of dietary adherence to the GFD lifestyle. 

There are several common foods that individuals with CD should avoid:

  • Pasta/noodles 
  • Breads, pastries, crackers and tortillas 
  • Cereals and granola 
  • Pancakes, waffles and french toast
  • Cooking ingredients such as croutons, stuffing, sauces and gravies (thickening agents such as flour usually contain gluten)
  • Beer 

Fortunately, you can still enjoy many good types of food if you have CD, such as:

  • Fruits and vegetables 
  • Meat, poultry and seafood 
  • Dairy products
  • Beans, legumes and nuts 
  • Most wines and spirits 
  • Processed foods certified as gluten-free 

Additionally, as we alluded to in the introduction, several companies are making gluten-free versions of cake, waffle and pancake mixes — and even pastas are made with alternative flours (such as lentil or beans).

A GFD has also been used to treat many other diseases. The diet has been successfully tested for treating conditions like NCGS, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), gluten ataxia, cognitive Impairment and psychiatric disorders

Should everyone consider a diet restricted in gluten intake? 

Given the many health benefits offered by a GFD for individuals suffering from CD and other conditions, it can be tempting to consider going gluten-free even if you don’t have the genetic, dietary and microbiome factors representative of such diseases. However, a GFD diet is not recommended for healthy individuals. Researchers have found that a GFD in healthy individuals induces a microbiome dysbiosis characterized by the loss of healthy species. The diet also leads to deficiencies in nutrients such as fiber, iron, calcium and vitamin D. It is only recommended when medically necessary and under the supervision of a physician who can provide supplements to avoid deficiencies in important vitamins and minerals. In this regard, celebrities and others may have (unknowingly) misled the general public about the benefits (or risks) of a GFD, which has helped fuel the gluten-free food industry — potentially putting people at risk. 

On the bright side, the popularity of the GFD, together with its success in helping those individuals with gluten-associated GI conditions or gluten sensitivity, has boosted an industry that provides expanded food options to those groups. So those suffering from unexplained GI symptoms may want to consult with a healthcare provider about reducing gluten consumption, since gluten sensitivity may be a more wide-spread issue than it used to be.

Key takeaways

Is gluten bad for you? The short answer is no. In people with specific conditions such as CD, wheat allergy and NCGS, gluten becomes toxic due to abnormally high levels and autoimmune responses against gluten proteins. Eliminating gluten from the diet can be extremely beneficial for (or, in the case of CD, necessary) individuals with these conditions. However, research shows that healthy individuals should not eliminate gluten, as doing so can lead to deficiencies in important vitamins and minerals and a dysbiotic gut microbiome. The general consensus among the medical community is that while “going gluten-free” sounds cool, this shift should only be undertaken after you have been evaluated by your medical provider.

Related Articles

Get insights
in your
inbox too.

Sign up for our newsletter to read
the latest in metabolic health.

Decode your metabolic health through personalized data

January’s virtual CGM analyzes your blood sugar to help you learn which foods to eat and avoid.