Healthy Living

Are Oats Gluten Free?

Our oldest daughter was in preschool when she was diagnosed with celiac disease. 

Unfortunately, like so many Americans that receive a celiac diagnosis, there was no information provided to us. We were on our own to figure it out. 

What is celiac disease?

It was an exhausting and overwhelming time in our lives.

This meant a lot of self-education and trial-and-error, largely at our daughter’s expense. (Sorry, Peanut!) And that led us to the problem of oats.

They’re easy, fast, cheap, and healthy. What’s not to love, right?

Well, for anyone with celiac disease or a wheat allergy, oats are complicated.

What’s the problem with oats?

Our daughter’s first source of accidental gluten contamination was Play-Doh (it’s made with wheat flour). Her second, was contaminated oats.

While inherently gluten free, oats are a potential source of gluten due to the manufacturing process in the US and many other areas of the world.

Most of the mills that process oats also handle wheat and other gluten-containing grains. This results in cross contamination of the oats by those grains.

If you have celiac disease or a wheat allergy, then contaminated oats are not safe for you.

Any package of oats that does not have a “Gluten Free” or “GF” label on it should be assumed to be contaminated.

What are Gluten Free Oats?

To be labeled gluten free, oats must either be:

  1. grown, harvested, and processed in a way that keeps them away from gluten-containing grains OR
  2. mechanically cleaned and separated to eliminate gluten.

The threshold for gluten on any packaged item, including those made with oats, must be below 20 parts per million (ppm) in order to include a gluten free label. This is true for most areas of the world.

The US, Canada, and Europe include gluten free oats as a healthy part of a gluten free diet for people with celiac disease.

The same is not true in either Australia or New Zealand.

GF Oats in AUS and NZ

The reasoning behind why Australia and New Zealand do not include oats as part of a safe gluten free diet gets a little scientifically technical. I am going to give the simplified version of this here.

Gluten is made up of two proteins: prolamins and glutelins.

They are found in the endosperm of grains. Their job is to store the plant’s proteins, which provide it nutrients so it can grow.

The prolamins and glutelins from each grain are called something different:

  • Wheat: Gliadin (prolamin), Glutenin (glutelin)
  • Barley: Hordein (prolamin), Hordenin (glutelin)
  • Rye: Secalin (prolamin), Secalinin (glutelin)
  • Oats: Avenin (prolamin), Avenalin (glutelin)

Collectively, these prolamins and glutelins are referred to as gluten. 

Medical studies consistently show that these proteins in wheat, barley, and rye trigger the autoimmune response in patients with celiac disease.

What happens when a celiac eats gluten?

Rice, corn, quinoa, peanuts, soy, etc. also contain prolamins and glutelins. However, they have been shown NOT to trigger the celiac autoimmune response.

These foods are generally considered a healthy and safe choice for celiac patients unless an allergy or some other medical contraindication exists.

Reactions to Oats?

Now, back to oats. Studies show that most patients with celiac disease can safely tolerate uncontaminated oats, i.e., gluten free oats.

Unfortunately, some people with celiac disease are unable to tolerate oats, even when they are certified gluten free. It may be that this group of people are intolerant or allergic to avenin.

Additionally, the structure of the avenin protein is similar to the structure of gluten. This may confuse some people’s bodies and trigger what’s called cross-reactivity.

This means that even though they didn’t actually eat gluten, their body thinks they did and reacts in the same way. This immune response to avenin may occur in as many as 1 in 12 people with celiac disease.

According to Coeliac Australia, the current tests for gluten can measure gliadin (wheat), hordein (barley), and secalin (rye).

Avenin (oats) is a slightly different protein. Currently, no test exists that can measure avenin quantity.

Australia and New Zealand have the most stringent gluten free labeling requirements in the world. In order to label a product as gluten free, it must contain “no detectable gluten” which means less than 3 ppm.

For these reasons, the Australian Food Standards Code prohibits the use of the “gluten free” label on oat-contain products. This applies to all oats, even those labeled as uncontaminated (i.e., wheat/gluten free). The same reasoning is applied in New Zealand.

What This Means for You

If you have been recently diagnosed with celiac disease, then it may be beneficial to remove oats from your diet along with all gluten-containing grains.

You may choose to test if your body can tolerate gluten free oats once your symptoms have fully resolved.

Follow these tips for reintroducing oats into your diet:

  • Introduce gluten free oats slowly to your diet and look for possible reactions. If you think you are reacting, remove oats from your diet. Wait 3-6 months before reintroducing them again.
  • Do not add gluten free oats to your diet if you are experiencing any gastrointestinal symptoms.
  • Choose certified gluten free oats.
  • Adults: Eat no more than 1 cup cooked or 2/3 cup raw oats per day.
  • Children: Eat no more than 1/2 cup cooked or 1/3 cup raw oats per day.

Keep in mind, an absence of symptoms does not necessarily indicate that oats are safe for you. Intestinal damage may still be occurring.

Regular celiac testing is the only way to confirm that you are successfully following a gluten free diet and not still experiencing damage.

This would typically be done yearly via serum antibodies blood work. These labs can be added to your routine physical with your family doctor or through a specialist.

An endoscopy-biopsy, which is done by a gastroenterologist, may also be used to check for signs of intestinal damage.

Layered Living is here to support you!

Dietary transition can be challenging. Having guidance and support during this process makes life easier.

Layered Living supports individuals and families that need help transitioning to a gluten free diet. Contact me of you have questions about getting tested for celiac disease.

Schedule a Consultation to learn more!


Ballantyne, S., PhD. (2020, April 26). How gluten (and OTHER Prolamins) damage the Gut. Retrieved April 13, 2021, from

Battye, O. J. (n.d.). Are oats safe for coeliacs on a gluten free dietyum. gluten free. Retrieved April 13, 2021, from

Beyond Celiac. (2020, August 17). Are oats gluten-free? Retrieved April 13, 2021, from

Celiac Disease Foundation. (2016, August 11). Oats and the gluten-free diet. Retrieved April 13, 2021, from

Celiac Kids Connection. (2020, March 24). What is gluten? Retrieved April 13, 2021, from

Coeliac Australia. (n.d.). Oats and the gluten free diet. Retrieved April 13, 2021, from

Intermountain Primary Children’s Hospital. (n.d.). Living gluten-free: A guide for kids, adults, and families. Retrieved April 12, 2021, from

Velji, B. (2014, February 17). Why gluten-free isn’t good enough (part 1). Retrieved April 13, 2021, from

Disclaimer: I am not a doctor. This blog post is general information only and is not to be substituted for medical advice, diagnosis, or treatment.

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