What is Gluten?

Gluten is the main storage protein found in wheat and comprises a mixture of hundreds of related proteins. Wheat is not the only type of grain that contains gluten. Other gluten-containing grains include:1

  • Barley
  • Rye
  • Triticale
  • Malt
  • Spelt
  • Kamut

Oats contain proteins similar to gluten, and they can also be contaminated with gluten from other grains during the harvesting and packing process.2

When consumed, the gluten found in all of these different grains is capable of causing the autoimmune response seen in celiac disease.1 An autoimmune response is where your immune system attacks and damages your own tissues, like your gut and skin.3 


Should I avoid gluten?

Although celiac disease is a common condition, it’s important to make sure that you’ve received a definitive diagnosis from your healthcare provider before starting a gluten-free diet.4 This is because:4

  • Celiac disease can only be diagnosed whilst you are still eating gluten.
  • If you need to start a gluten-free diet, advice from a dietitian will be required. 
    • This is because a poorly planned diet could be difficult to maintain and may even result in malnutrition.
  • A gluten-free diet can be expensive.

What foods contain gluten?

Gluten is an important component of many different foods, where it’s used to improve texture, flavor, and moisture retention. Many people realize that grain-based products contain gluten, but gluten may also be used as an additive in processed foods.1

Some common foods, drinks, and sauces that may contain gluten and trigger an autoimmune response if you have celiac disease include:

It’s important to read the food product label or seek information before eating certain foods. If an ingredient containing gluten has been used, it must be highlighted in the ingredients list. Some more surprising examples of where you might find gluten include:

Gluten can also be found in non-food items, such as:

  • Herbal or nutritional supplements
  • Over-the-counter medications, vitamins, and supplements
The gluten-containing products mentioned on this page are just examples, and don’t form a complete list of food and non-food items that may contain gluten. If you’ve been diagnosed with celiac disease or another gluten-related disorder and are considering a gluten-free diet, it’s important to consult a dietitian to ensure your diet is appropriate.4  

1. Biesiekierski J R. What is gluten? J Gastroenterol Hepatol 2017;32(S1):78-81

2. Fric P, Gabrovska D, Nevoral J. Celiac disease, gluten-free diet, and oats. Nutr Rev 2011;69(2):107-115

3. Gujral N, Freeman H J, Thomson A B. Celiac disease: prevalence, diagnosis, pathogenesis and treatment. World J Gastroenterol 2012;18(42):6036-6059

4. Al-Toma A, Volta U et al. European Society for the Study of Coeliac Disease (ESsCD) guideline for coeliac disease and other gluten-related disorders. United European Gastroenterol J 2019;7(5):583-613