Are Oats Gluten-Free? Oats and Coeliac Disease

Oats are botanically a different cereal from wheat, barley and rye, and in the narrow sense they contain no gluten, but ordinary oats are very often contaminated with those grains during growing, transport and milling. People with coeliac disease should therefore choose only oat products that are explicitly labelled "gluten-free". In addition, some people with coeliac disease may react to avenin, a protein in oats, so adding oats to the diet should always be discussed with a doctor.

Do oats contain gluten?

Gluten in the narrow sense is made up of proteins from wheat, rye and barley. Oats contain a related protein called avenin. In the list of 14 allergens, oats are listed among the "cereals containing gluten", together with wheat, rye, barley, spelt and khorasan wheat. They must therefore be highlighted as an allergen in the ingredients list. More about the list is in the 14 EU allergens.

In practice this means two things:

Oat products are not considered gluten-free by default.
Oats can be labelled "gluten-free" only if they meet special conditions.

Why ordinary oats are a problem: contamination

The biggest risk for people with coeliac disease is not the oat itself, but what gets mixed in on the way from field to plate.

Growing. Oats are often grown in rotation with wheat or barley, so grains from the previous crop of other cereals may remain in the field.
Harvest and transport. The same combine harvester, store or lorry may carry different cereals.
Milling and processing. Shared mills and production lines can carry over residues of wheat.
Preparing food. In the kitchen, rolled oats can be mixed with other cereals, for example in muesli or in a bakery.

That is why "ordinary" rolled oats from a regular shop are not recommended for coeliac disease unless they are labelled gluten-free.

Gluten-free oats under Regulation 828/2014

In the EU a food can carry the "gluten-free" label if it contains no more than 20 mg of gluten per kilogram. The conditions are set by Implementing Regulation (EU) No 828/2014. For oats, they can be labelled "gluten-free" only if they were produced, prepared or processed in a way that prevents contamination by wheat, rye, barley or their crossbreeds, and the gluten content does not exceed the limit of 20 mg/kg.

In practice such oats are called "pure" or "gluten-free" oats. Producers grow them in separate fields, use their own machinery, and sort and test the grain after harvest.

What to look for when shopping:

Look for the explicit "gluten-free" label (often with the crossed-grain symbol).
Do not assume that flakes are gluten-free just because they are "organic", "wholegrain" or "natural". Such wording says nothing about contamination.
Check the other ingredients too. Muesli, bars and porridge mixes can contain other cereals.
Check whether the product carries a warning about traces of gluten. More in May contain traces.

Avenin: why some people react even to pure oats

Avenin is a protein from oats with a structure similar to the proteins in gluten. Most people with coeliac disease tolerate pure oats well, but a small proportion can react to avenin too, with symptoms or damage to the lining of the gut.

You cannot reliably tell from symptoms who reacts to avenin. That is why adding oats to a gluten-free diet is recommended only after agreement with a doctor and under their supervision:

after the diagnosis has been made and your condition has improved on a gluten-free diet,
usually in small amounts,
with monitoring of symptoms and, on your doctor's instructions, laboratory results.

The exact procedure is decided by your doctor, especially a gastroenterologist.

Oats in children and during diagnosis

If you suspect coeliac disease, do not start a gluten-free diet on your own, as it can distort the test results. Talk to a doctor. For children, the doctor decides whether oats go into the diet. More about the differences between allergy, intolerance and coeliac disease is in Allergy, intolerance and coeliac disease.

Oats in everyday food: where you will find them

Oats are not only in porridge. They appear in muesli and granola, oat biscuits, bars, some bakery products, oat drinks, ready-made foods, protein products and as a thickener. On a gluten-free diet, each such product is judged separately by its label and ingredients list.

Be careful with gluten-free products that contain oats, too. If your doctor has decided that you should not eat oats, you need to read the ingredients of gluten-free products as well. A "gluten-free" label on its own does not mean the product contains no oats.

How to approach introducing oats

A typical procedure recommended by doctors looks like this, but always follow your individual instructions:

First, your health is stabilised on a strict gluten-free diet.
Only then, in agreement with your doctor, are pure gluten-free oats introduced, usually in small amounts.
You watch for symptoms and, on your doctor's instructions, have follow-up tests.
If symptoms appear, oats are left out and the doctor decides what happens next.

When shopping, prefer products with oats labelled "gluten-free" and stick to one tried-and-tested brand until your doctor tells you otherwise.

Oats in a restaurant

The biggest problem is verifying where the oats come from and how they are prepared. In restaurants and bakeries that are not gluten-free, oats are often contaminated or prepared on shared surfaces. With porridge, granola, oat cakes or bread, ask:

Are the oats labelled gluten-free?
Are they prepared with separate utensils?
Does the dish contain other cereals (wheat, barley, rye)?

More questions are in How to ask about allergens in a restaurant and Hidden gluten. You can also find gluten-free breakfasts and baked goods in Gluten-free breakfast and Gluten-free bakeries.

Oat milk and drinks

Plant-based oat "milk" is another common question. It is made from oats, so unless it is explicitly labelled "gluten-free", it may not be suitable for people with coeliac disease. For each product, follow the label on the pack.

How AvoiDino can help

In AvoiDino you can set gluten as your allergen and narrow down dishes and restaurants. The app helps you find your way around, but it does not replace asking the staff, and with oats it certainly does not replace your doctor's advice.

Frequently asked questions

Are oats gluten-free?

Oats are botanically a different cereal from wheat, barley and rye, and in the narrow sense they contain no gluten, but ordinary oats are often contaminated with gluten from those cereals. You can treat them as gluten-free only if they are explicitly labelled "gluten-free".

Can people with coeliac disease eat oats?

Most people with coeliac disease tolerate pure gluten-free oats, but not all do. Talk to your doctor about adding oats to your diet.

What is avenin?

Avenin is a protein found in oats that is similar to gluten. Some people with coeliac disease react to it even when the oats are pure.

Which oats can be labelled "gluten-free"?

Oats that were produced and processed in a way that prevents contamination by wheat, rye or barley, and that contain no more than 20 mg of gluten per kilogram.

Are rolled oats from an ordinary shop suitable for coeliac disease?

Not unless they are labelled "gluten-free". The risk of contamination is high, so with coeliac disease only flakes labelled "gluten-free" are recommended.

Sources

Commission Implementing Regulation (EU) No 828/2014 on the requirements for the provision of information to consumers on the absence or reduced presence of gluten in food.
Regulation (EU) No 1169/2011 of the European Parliament and of the Council, Annex II.
Husby S. et al.: ESPGHAN Guidelines for Diagnosing Coeliac Disease 2020. Journal of Pediatric Gastroenterology and Nutrition, 2020.

This information is general and does not replace medical advice. If you have an allergy, always check the ingredients with the staff.