What Is Gluten?

The popularity of gluten-free diets, even among people without gluten sensitivity or celiac disease, may lead you to wonder if gluten is bad for you. But what is gluten, anyway?

Gluten is a collection of proteins in wheat. It’s used like glue to help food and other products keep their shape. Gluten can cause negative reactions in some people, with symptoms and complications.

The Science of Gluten

The proteins in wheat, barley, and rye are sources of gluten. Oats and corn don’t have the same proteins, but because they come into contact with other grains during harvests, they can be contaminated.

When wheat flour (or flour with gluten proteins) is mixed with water, it becomes gluten. The proteins become flexible, sticky, and elastic. This makes it ideal for batters and doughs.

Celiac Disease, Gluten Sensitivity, and Wheat Allergies

Gluten-free diets are important for people with celiac disease and gluten sensitivity.

Celiac disease. One in 100 people around the world has celiac disease. It’s a genetic autoimmune disorder that makes you sensitive to gluten. When you eat it, a reaction in the small intestine leads to an attack on the villi, finger-like projections that help your body absorb nutrients. Celiac disease can lead to long-term complications.

Symptoms of celiac disease include:

  • Diarrhea
  • Bloating or gas
  • Fatigue
  • Belly discomfort
  • Constipation
  • Nausea
  • Vomiting
  • Anemia
  • Loss of bone density (osteoporosis) and softened bones (osteomalacia)
  • Itchy or rashy skin
  • Mouth ulcers
  • Joint pain

Your symptoms will be different from others’. For example, children are more likely to have digestive problems than adults.

Gluten sensitivity. Also known as gluten intolerance, gluten sensitivity causes symptoms similar to celiac disease, without the damage to the small intestine.

People with gluten sensitivity are likely to have symptoms unrelated to their digestive system, such as:

  • Headache
  • Joint pain
  • Numbness in limbs
  • Cloudy mind

As with celiac disease, there aren’t many treatment options for gluten sensitivity. The best option is to stick with a gluten-free diet.

Wheat allergy. Wheat allergies are different from celiac disease and gluten sensitivity. Someone with a wheat allergy is allergic to wheat proteins, which may be gluten. The symptoms of a wheat allergy may be digestive or may include:

  • Irritation, itching, and swelling around your mouth and throat
  • Itching and swelling of your skin
  • Congestion
  • Trouble breathing

If you have a wheat allergy, you will need to stick to a wheat-free diet.


Gluten Sources and Alternatives

Many foods and drinks have gluten. But you can avoid certain types of food and ingredients on a gluten-free diet.

Avoid foods and drinks with these grains:

  • Wheat (including durum, einkorn, emmer, Kamut, and spelt)
  • Barley
  • Rye
  • Triticale

Oats are gluten-free, but they can come in contact with gluten during production. Oats labeled gluten-free are usually safe, but some people with celiac disease may still be sensitive to them.

Common foods. There are many gluten-free alternatives for common foods with gluten, such as:

  • Pasta and noodles
  • Crackers and croutons
  • Bread
  • Pastries and baked goods
  • Breading and breadcrumb mixes
  • Sauces and gravies
  • Flour tortillas
  • Beer and malt beverages

Check food labels and nutrition facts, or ask the person preparing your food to see if these things have gluten:

  • Granola bars
  • French fries and potato chips
  • Lunch meats
  • Candy
  • Soup
  • Tortilla chips
  • Salad dressings, sauces, and marinades
  • Meat substitutes
  • Restaurant eggs (some use pancake batter as a thickener for scrambled eggs)

Because gluten is a bonding agent, it’s also used in some non-food products:

  • Cosmetics such as lipstick, lip gloss, and lip balm
  • Dental products
  • Vitamins and nutritional supplements
  • Drugs and medications
  • Toy dough

Alternatives for typical ingredients with gluten include:

  • Flour: almond meal flour, coconut flour, cornstarch, millet, pea flour, potato flour, soy flour
  • Oats: amaranth, buckwheat, sorghum
  • Thickening agent: Guar gum
  • Grains: brown rice, white rice, wild rice, quinoa
  • Other: corn, potatoes

Complications of Going Gluten-Free

Gluten-free diets have become popular with people who don’t have gluten sensitivity or celiac disease. They may believe that:

  • A gluten-free diet will help you lose weight.
  • Your overall health improves.
  • You’ll have better gastrointestinal health.
  • Your athletic performance will improve.

But there’s no research to support these claims.

Fewer nutrients. You may wonder whether gluten-free alternatives are healthier. Some studies have found that people who are on a gluten-free diet tend to gain weight. These foods also often have fewer nutrients such as iron, calcium, and fiber, and more sugar and fat.

Higher costs. Before committing to gluten-free foods, think about the cost. Most gluten-free foods have a higher price tag than what they replace. The expenses of a gluten-free diet can be significant.

WebMD Medical Reference Reviewed by Poonam Sachdev on June 22, 2021



Beyond Celiac: “What Is Gluten?” “What Is Non-Celiac Gluten Sensitivity?”
Celiac Disease Foundation: “Sources of Gluten,” “What is Celiac Disease?” “What is Gluten?”
Celiac Kids Connection: “What Is Gluten?”
Gluten Intolerance Group: “Gluten Sensitivity.”
Harvard Health Publishing: “Ditch the Gluten, Improve Your Health?”

Mayo Clinic: “Celiac disease,” “Gluten-free diet,” “Wheat allergy.”

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