Oats - commonly asked questions

There is no standard way that oat tolerance should be monitored, and internationally the approach varies. An individual approach tailored to your needs in collaboration with your medical team is important. 

What we do know: 

Antibody blood tests/ serology are not a useful tool when monitoring the immune response to oats.

Symptoms    

Overseas, symptoms (or lack thereof) are commonly used as a marker of pure oat tolerance. While this seems applicable for many, further studies are required to determine whether this is an appropriate means of monitoring tolerance for all people with coeliac disease who wish to try oats. Planning is underway for further research to investigate this very area. 

Biopsy   

A biopsy may be recommended by your specialist; it is important to discuss the best approach for you with your doctor. 

It is important that the entire clinical picture be examined in context; there may not be one single approach that suits every person. Importantly, you should receive relevant monitoring and follow-up care to help manage your coeliac disease. 

Many international guidelines do not specify the quantity of oats that should be used when first introducing them to a gluten-free diet. In research studies there is evidence to support the general safety of 50-70g of pure oats (approx. 1/2-3/4 cup of uncooked rolled oats) for the majority of adults with coeliac disease (25g for children). 

The suggestion to start with smaller amounts of pure oats and gradually increase the quantity consumed is a sensible approach. This approach (along with drinking adequate water) will also help to counteract the confounding symptoms that some may experience due to an increase in fibre intake. 

Should your medical team recommend you undertake an oats challenge – note that symptoms may occur at the start, but some people report these symptoms fade in a few weeks if you keep eating small amounts of oats, and symptom tolerance to oats can sometimes be established. 

If it is decided that a biopsy monitored oat challenge is appropriate, this would involve:  

• pre-challenge biopsy to obtain baseline data (this can be the biopsy done as part of normal follow-up care, or a separate biopsy done specifically for the oat challenge)
• a challenge period with pure oats (approximately 50-70g most days) for 3 months or longer
• a subsequent biopsy to confirm there is no evidence of bowel damage. 

When we talk about ‘reacting’ to oats, this can refer to symptoms, subtle markers of inflammation in the blood, raised inflammatory cells and less commonly villous atrophy. The significance of some of these ‘reactions’ is not clear, hence the need for an individual approach in collaboration with your medical team.  Recent studies show, the symptoms in many fade with time, as the body gets used to the new grain again, and the villi remain unharmed. Medical research continues to better understand people’s oat tolerance.

While overseas you will find uncontaminated oats labelled as ‘gluten free’, there is no legislation in Australia mandating what uncontaminated or pure oats should be called. This can make it difficult to confidently identify oats that have been specially produced to be free of wheat, rye and barley contamination (pure oats).

Some terminology that is used includes ‘wheat free’, ‘uncontaminated’, ‘low gluten’, and ‘pure’, but the terminology is used inconsistently leading to ambiguity and confusion. For example, ‘wheat free’ may be used on a product where rye and/or barley contamination may still be an issue.  Please check the ‘May Contain’ statements on the oat packets. There should be no “may Contain” statement for wheat, rye or barley. Check the brand websites, or contact manufacturers, to determine if they test for gluten cross contact and if this is below 3-5 ppm or the international standard of 20ppm.

If an oat is labelled ‘organic’ does that mean it is suitable?   

No, an ‘organic’ claim indicates the oats have been grown without pesticides; this in no way ensures they have been grown to be free of wheat, rye or barley contamination.

How is oat avenin different to the prolamins in wheat, rye and barley?   

The term ‘gluten’ is used to describe the grain storage proteins from wheat, rye and barley that are toxic to people with coeliac disease. There is a similar protein in oats called avenin. However, oats are less toxic to people with coeliac disease because there is not much avenin in oats, and the avenin present is less likely to trigger harmful immune responses compared to wheat, rye and barley. 

What does it mean when oats are labelled ‘gluten free’   

This terminology is used overseas. The Australian food code differs to the regulations in Europe, UK and the USA, where oats can be marketed as ‘gluten free’.  

These oats have been grown under specific conditions to reduce the cross-contact with wheat, rye and barley grains. The current enzyme-linked immunosorbent assay (ELISA) used to test for ‘gluten’ in food can measure gliadin, hordein, and secalin, found in wheat, barley and rye. This test can determine if any grains from wheat, barley or rye have been mixed in with the oat grains.   To be labelled gluten free overseas, the contamination with wheat, rye or barley grains must measure less than 20ppm (parts per million). 

FSANZ prohibits the use of a ‘gluten-free’ claim on oat-containing products. There is no suggestion that the current food code be amended to allow oats to be labelled ‘gluten free’ in Australia.

Is gluten-friendly allowed?   

No, due to its ambiguity, gluten-friendly is not a permitted term on oats or any food product per the food code. Only ‘gluten-free’ or ‘low gluten’ claims are permitted on food products. FSANZ Products containing oats cannot be labelled ‘gluten free’ in Australia and New Zealand. 

 What is the latest Australian research into oats?   

The long-awaited study at WEHI into oat safety has now been completed, and the results were published in February of 2025   https://pubmed.ncbi.nlm.nih.gov/39961645/  

The study concluded that “gluten-contamination-free oats can trigger acute dose-dependent immune and symptoms responses, but usually at a level insufficient to cause sustained symptoms or enteropathy (abnormality). In 1 of 29 (3%) participants, oat avenin triggered a pro-inflammatory wheat-like response, highlighting that a minority of CD patients may need to exclude oats. Informed choice regarding oats ingestion in coeliac disease is important”.

A study is also being mapped out to review and guide future approaches for the introduction and monitoring of those with coeliac disease who wish to trial pure oats. With this study, we hope to find answers to some of the questions that remain and guide standard practice in this space.