By Amy Burkhart MD, RD

Are oats gluten-free? It’s a question that leaves many scratching their heads, especially when it comes to the conflicting online information. While oats themselves don’t contain gluten, the answer to ” Are oats gluten-free?” isn’t a simple yes or no. It’s no wonder the topic remains confusing.

It gets even more murky when you have to decipher the terms associated with oats. Is there a difference between purity protocol oats, regular oats, certified gluten-free oats, or organic oats regarding safety on a gluten-free diet?  Is it different if you have celiac disease vs. gluten sensitivity?  What about the gluten-free Cheerios and Oreo controversies? Let’s dive into the details and clear up the confusion surrounding oats, their place in a gluten-free diet, and what you should do about oats if you follow a gluten-free diet.

Oats do not naturally contain gluten. Oats in the United States are cross-contaminated during farming and production.

While oats don’t naturally contain gluten, they are often cross-contaminated with wheat during growing, harvesting, and processing. For people with celiac disease or severe gluten sensitivity, even small amounts of gluten from cross-contaminated oats can cause serious health issues. So, it’s important to choose oats carefully. Let’s explore how to find oats that are as safe as possible for anyone following a strict gluten-free diet.

It’s crucial to understand that not all gluten-free oats are created equal. You will see labels saying one of the following: oats, gluten-free oats, certified gluten-free oats, organic oats, or purity protocol oats. What is the difference? Let’s start with  “certified gluten-free oats”.

Are “certified gluten-free oats” safe?

Certified gluten-free oats have gone through one of the gluten-free certification programs for testing of their products. Products are certified gluten-free to <20ppm gluten, the standard to meet the legal definition of “gluten-free”. Some certification programs test for lesser amounts, but that is not legally required.

Gluten-free certified oats are sometimes produced using traditional farming methods. This means oats may be grown in fields alongside gluten-containing grains, rotated in the same fields or use the same storage silos as gluten grains. All this can cause cross contamination of the oats with wheat.

After harvest, a mechanical or optical sorting method may be used to “remove” the gluten. However, this process doesn’t always ensure complete elimination of rogue wheat grains, which means there’s still theoretically a risk of cross-contamination. Certification testing minimizes this risk, but typically a company does not test every batch of their oats.

So, while this process decreases the odds of gluten contamination, it is not zero. Many gluten-free oats on the market are gluten-free certified, so the decision is personal about whether you choose to eat these oats.

Purity protocol oats are the safest oats for people on a gluten-free diet.

In contrast to certified gluten free oats,  “purity protocol oats”  are grown in dedicated fields, separate from gluten-containing crops. They undergo strict handling procedures to ensure no cross-contamination occurs during growing, harvesting, or processing. These oats are specifically designed to meet the needs of individuals with celiac disease or severe gluten sensitivity.

While purity protocol oats are the safest option, they can be hard to find and often come with a higher price tag. If these aren’t available, the next best choice is certified gluten-free oat products.

Oats without any labeling of “gluten-free” or “purity protocol” are not recommended on a gluten-free diet

The first study in the New England Journal of Medicine on the amount of gluten in oats found that most oats in the US ( McCann’s, Quaker, Country Choice) contained gluten in some batches of each brand. This is Russian roulette for someone with celiac disease or severe gluten sensitivity. This type of oats are not recommended on a strict gluten-free diet.

Organic oats are not always gluten-free.

Organic oats are not necessarily gluten-free. If they do not say “gluten-free” organic oats, “purity protocol gluten-free oats,” or “certified gluten-free oats,” assume they are cross-contaminated and avoid them.

This wording won’t be on the label but is used by General Mills, the makers of gluten-free Cheerios & Chex.

Some companies, such as General Mills, the makers of gluten-free Cheerios, and gluten-free Chex, use a mechanical sorting method to “find” the wheat kernels amongst the oats. If you think this sounds difficult and a bit dicey, it is. The makers of GF Oreos may also use this process, but have refused to answer questions about the sourcing of their oats.

In her report on gluten contamination levels of oat products, Gluten Free Watchdog mentioned that five products using mechanically sorted oats tested above 20 ppm, meaning they do not qualify as gluten-free.

I do not recommend that anyone with celiac disease use these products due to the questionable methods and numerous reports of illness with these products. Many people on a gluten-free diet  will still choose to eat these products, but others avoid them due to severe reactions. If you are still experiencing symptoms and use these products, I recommend you stop using them.

Oats, Including GF Oats,  Act Like Gluten In Some People With Celiac Disease

Oats themselves do not contain gluten, but they do contain a protein that closely resembles gluten. For some individuals, particularly those with celiac disease, this protein can trigger symptoms similar to a gluten reaction.

Research shows that about 8% of people with celiac disease react to oats, even if the oats are certified gluten-free or purity protocol. In these individuals, consuming oats can lead to a range of symptoms that vary from mild to severe, cause intestinal damage, and elevate celiac antibody tests. Based on my clinical experience, this reaction feels slightly different from a person’s typical gluten response, though it can still be quite debilitating.

Symptoms of an oat reaction differ from person to person, much like a ‘gluten reaction’. Some of the most common symptoms include muscle pain, headaches, digestive distress, neurological issues (such as anxiety, depression, or muscle spasms), flu-like symptoms, and more. In some cases, these effects can last for days or even weeks.

For those with celiac disease or gluten sensitivity, it is essential to monitor how your body reacts to oats, even if they are labeled gluten-free.

If someone is newly diagnosed with celiac disease, it is recommended that they avoid oats until symptoms resolve. This may be 6 months or longer. Then, they can introduce 1/4 cup of oats every 4 days to assess tolerance and increase amount and frequency as tolerated. There is no test to determine if someone is in the 8% of people with oat intolerance if they have celiac disease. Elimination and reintroduction are the only ways to determine this.

For the gluten-intolerant person, oats may or may not be problematic.

There are no studies on this issue. Some gluten-intolerant people state they can not tolerate oats, even GF oats. An elimination of oats for 3-4 weeks followed by reintroduction of oats is the best way to uncover a reaction to oats.

This reaction may be due to undiagnosed celiac disease, since many people start a gluten-free diet without testing for celiac disease or perhaps have a sensitivity to other components of oats. Many people with gluten sensitivity have  FODMAP intolerance and are not sensitive to the gluten in wheat. They are reacting to the sugar component of the grain, not the gluten. A person with  FODMAP intolerance can typically tolerate oats in small amounts.

The oat milk market has experienced significant growth recently. In 2024, the global market for oat milk was valued at approximately $717.8 million and is projected to reach $1.845 billion by 2033. While some companies, cafes, and dining establishments choose gluten-free oats and oat milk for their products, this isn’t universal.

It’s essential to verify whether the oat milk used by an establishment is certified gluten-free. If you have gluten intolerance or celiac disease, always ask the barista or server about the gluten-free status of the oat milk before consumption. For individuals with oat intolerance or oat allergy, it’s advisable to avoid all products and drinks containing oat milk, regardless of their gluten-free certification.

If The Establishment Uses GF Oatmilk

If you do not react to oats, you can decide if you want to have it or not based on the above information.

If You React To Oats Or The Establishment Does Not Use GF Oat Milk

Because oat milk is so popular, if the establishment uses oat milk that is not gluten-free, the equipment can be cross-contaminated. This may affect someone with celiac or severe gluten allergy.

• Request a Clean Pitcher – Ask the barista to use a clean pitcher and steam the spout with water before making your drink with a different type of milk.

• Mention an “Allergy” – While celiac disease is not technically an allergy, using that term helps staff understand the seriousness of cross-contact.

• Choose an Iced Coffee – Opt for an iced coffee drink that doesn’t require steaming milk, avoiding the risk of cross-contamination.

• Go Without Steamed Milk – Select a coffee drink that doesn’t include steamed milk at all, such as an Americano or black coffee.

• Ask for Milk on the Side – Order your espresso drink with your preferred milk served separately. While the milk won’t be steamed, this eliminates the risk of contamination.

• Enjoy the Social Outing – If coffee feels risky, don’t skip the occasion! Choose a different beverage and still enjoy the experience of going out.

Ask, Ask, Ask

• Many gluten-free products now contain oat flour. However, not everyone, even those making the baked products, realizes the specifics about oats and gluten.
• Always ask. If the staff seems unsure or confused about whether the oat flour is gluten-free—or you cannot tolerate oats—it’s best to avoid the product.

Read Labels

• Because of the desirable properties oat milk/oat flour adds to products, many favorite GF products now contain oats. ALWAYS read labels, even if you have used a product for years.
• If the label doesn’t specifically say “GF oats,” contact the company for confirmation.
• Even if the product has a “certified gluten-free” label but doesn’t mention GF oats, it’s best to contact the manufacturer for clarification.
• If it is a General Mills product, the decision is yours, but understand the risks. Do not eat it if you experience any symptoms.

Stay Informed and Speak Up!

• Only Eat Oats Labeled: “Gluten-free”,” Certified gluten-free” or “Purity Protocol”. Do not eat products that say “oats” without contacting the manufacturer
• Avoid Oats Always If You React To Oats: This is especially important if you have celiac disease. Oats can act just like gluten and cause intestinal damage and elevation of celiac antibodies
• Please Read The Blue Information Box Above: Recent recommendations from Tricia Thompson R.D. a.k.a. The Gluten Free Watchdog recommend all people with celiac disease avoid ALL oats
• Always Ask Questions! If you’re unsure whether an oat milk brand is gluten-free, skip it or contact the manufacturer directly.
• Know Your Brands. Find out which oat milk your favorite café or restaurant uses so you can make informed choices.
• Get a Free Resource! Sign up for my email list above to receive a free PDF to help you navigate gluten-free oat milk options at the main corporate cafes nationwide.
• Spread Awareness. Educate others about the difference between regular oats and certified gluten-free oats—awareness is key to change.
• Advocate for Change. When dining out, ask if the oat milk is gluten-free. If it’s a corporate chain and they don’t offer a gluten-free option, contact their headquarters—they may not even be aware of the issue. Enough customer requests could lead them to switch brands.
• Be Proactive! If you’re a regular customer, ask your favorite café to consider using gluten-free oat milk. You never know—they might say yes!
• Caution With General Mills Products: I do not recommend these products if you have celiac disease. I know everyone will not take that advice but if you choose to eat them and experience symptoms- stop eating them.