What Is Gluten?

Gluten is an umbrella term used to describe a group of proteins called prolamins and glutelins found in grains such as wheat, barley, and rye.1

Gluten is highly elastic and gives baked goods, like bread, their chewy texture. In addition to being found in many grains and bread products, gluten is added to a variety of foods and beverages like ketchup, ice cream, and soy sauce.

Most people consume gluten on a daily basis; the average American eats about 10 to 20 grams of gluten per day.2 Although most people can have gluten without issue, it can trigger symptoms and health issues in people with certain medical conditions or in people who are sensitive to gluten.

What Foods Contain Gluten?

Gluten is found in a number of grains and grain products as well as in other foods and drinks. The following foods contain gluten and should be avoided by people on gluten-free diets:3

Gluten-containing grains

• Wheat
• Rye
• Triticale 
• Farina
• Spelt
• Kamut
• Wheat berries
• Barley
• Faro
• Couscous

Keep in mind that although oats are naturally gluten-free, they are easily contaminated with gluten during processing. For this reason, people who need to avoid gluten for medical reasons should purchase certified gluten-free oats. 

Baked Goods Made With Gluten-Containing Grains 

• Breads like white bread, sourdough, rye bread, and whole-wheat bread
• Wheat-based crackers
• Flour tortillas
• Flatbreads
• Pancakes and waffles  
• Pastries, cookies, and cakes 

Pasta 

• Noodles like ramen, udon, or soba
• Spaghetti
• Dumplings
• Ravioli
• Gnocchi

Snack Foods and Sweets

• Pretzels
• Flour-based tortilla chips 
• Cheese crackers 
• Certain candies and candy bars
• Some ice creams 
• Some cereal, energy, and granola bars 

Some Condiments 

• Soy sauce
• Some salad dressings and ketchups 
• Marinades made with flour 
• Barbecue sauce
• Cream sauces 
• Gravy mixes 
• Malt vinegar

Certain Drinks

• Beer
• Malt beverages 
• Bottled wine coolers
• Some chocolate milk products 

Other Foods and Ingredients 

• Bread crumbs and croutons 
• Brewer's yeast 
• Cream-based soups and soup mixes 
• Brown rice syrup made with barley 
• Meat substitutes like seitan

What About Gluten-Free Foods?

Many foods, like fruits, vegetables, eggs, and legumes are naturally free from gluten and are safe to consume for people who need to follow gluten-free diets.4

People following gluten-free diets should look for food products that carry a certified gluten-free label, particularly when shopping for breads, pastas, and snack foods.5

Products with labels like "gluten-free," "no gluten," "free of gluten," or "without gluten" must have less than 20 parts per million of gluten. This is considered a safe level for people with conditions like celiac disease.5

Is Gluten Bad For You?

Gluten isn’t inherently bad or unhealthy, and most people don’t need to avoid gluten. However, gluten can cause health issues in people with certain conditions, like celiac disease, non-celiac gluten sensitivity (NCGS), and some autoimmune diseases.

Some experts say even people without gluten-related medical issues should avoid gluten. This is because certain plant proteins called prolamins found in wheat and other grains are highly resistant to being broken down in the body.6

Normally, the body breaks down proteins into singular amino acids—commonly referred to as the building blocks of protein—and uses them to build new proteins. When the body does not completely digest prolamins, they can form larger chains of amino acids called peptides that cross through the intestines into the rest of the body.7

These peptides have been found to negatively interact with the gut and immune system. They have also been shown to appear in non-celiac autoimmune diseases like inflammatory bowel disease (IBD).7

It’s also important to note that gluten may not be the only problematic compound found in wheat and wheat-based products. Some research indicates other wheat proteins, such as FODMAPs, may also contribute to symptoms in people who are sensitive to wheat and wheat products.8

Keep in mind that research in this area is ongoing. More studies are needed to fully understand how gluten impacts overall health and whether restricting gluten is appropriate for everyone. 

Who Should Avoid Gluten?

People with gluten-related conditions need to avoid gluten to control symptoms and protect their body from damage. Additionally, some evidence suggests other populations may also benefit from a gluten-free or low-gluten diet.

People following gluten-free diets may be more prone to developing one or more nutrient deficiencies. It’s important to choose foods that cover your nutritional needs and supplement with vitamins and minerals when necessary.9

People With Celiac Disease

Celiac disease is an autoimmune disease, meaning the immune system malfunctions and attacks healthy cells in the body. In celiac disease, the ingestion of gluten triggers a response from the adaptive immune system, a part of the immune system that protects the body from specific pathogens, or disease-causing organisms.10

In people with celiac disease, the consumption of gluten causes damage to cells lining the small intestine, which leads to nutrient malabsorption, digestive symptoms like diarrhea, and weight loss. Additionally, this disease can cause a number of other serious health issues including poor growth in children, anemia, osteopenia or osteoporosis, migraines, miscarriages, anxiety, and depression.10 

Celiac disease impacts around 1% of the world’s population, but the number of people being diagnosed with celiac disease seems to be rising. People with other autoimmune diseases, like type 1 diabetes, people who have a first degree relative who has celiac disease, and people assigned female at birth are more likely to develop this condition in their lifetimes.10

The only currently recommended treatment for celiac disease is a strict gluten-free diet. Most people with celiac disease find that their symptoms resolve within days or weeks of transitioning to a gluten-free eating pattern.10

People With Non-Celiac Gluten Sensitivity

NCGS is a term used to describe people who are intolerant to gluten and do not have celiac disease or a wheat allergy.11  

NSGS is much more common than celiac disease and wheat allergy. Although the worldwide prevalence of NSGS is still unknown, study findings suggest that between 0.49 to 14.9% of the population may be intolerant to gluten. Like celiac disease, NCGS is more common in women and in people with autoimmune diseases like type 1 diabetes.11

Although NCGS differs from celiac disease, it’s also considered an immune-related condition. In people with NCGS, ingesting gluten triggers a response from the innate or nonspecific immune system, which is your body’s first line of defense against pathogens. This causes symptoms such as abdominal pain, bloating, diarrhea, nausea, acid reflux, headaches, and joint pain.11

People with NCGS should avoid gluten and gluten-containing products, though some people with NCGS may be able to tolerate small amounts of gluten without experiencing significant symptoms. 

People With Wheat Allergy

Some children and adults are allergic to specific proteins found in wheat and wheat-containing products. Wheat allergy differs from celiac disease as it involves a different immune response. Celiac disease is an autoimmune disease, not a food allergy. Food allergies result in a rapid onset of symptoms like nausea and even anaphylaxis, a potentially life-threatening condition that can cause breathing difficulties.12

Wheat allergy is more common in children than adults. Around 65% of children outgrow their wheat allergy by age 12. It’s currently estimated that between 0.2 to 1% of the population is allergic to wheat.12

Children and adults with wheat allergy must follow a wheat-free diet by avoiding wheat and all wheat-containing products. People with wheat allergies must also avoid inhaling wheat, which can occur when handling wheat-containing products.12

Other Populations That May Benefit from a Gluten-Free Diet

Some evidence suggests a gluten-free diet may benefit people with certain health conditions, like autoimmune diseases and some mental health disorders.

For example, studies show following a gluten-free diet may improve symptoms in people with conditions like:131415

• Hashimoto’s thyroiditis
• IBD
• Psoriasis
• Multiple sclerosis
• Schizophrenia

However, researchers note there is currently not enough evidence to justify recommending a gluten-free diet to all people living with these health conditions.14

If you have a health condition that may benefit from a gluten-free diet, it’s best to work with a healthcare provider or a registered dietitian to develop a safe and balanced gluten-free eating plan.

A Quick Review

Gluten is a collective name for a group of proteins naturally found in foods like wheat and barley. It's also commonly added to foods like candy and salad dressings. 

Gluten isn’t inherently bad for health, but people with celiac disease, wheat allergy, and NCGS need to follow a diet free from gluten to avoid symptoms, which can range in severity.

If you think you might have celiac disease, NCGS, or another condition that might benefit from following a gluten-free diet, talk to your healthcare provider. They can offer guidance on how to follow a gluten-free diet in a safe and healthy way.