If you’re confused and frustrated about whether or not you can eat oats on a gluten-free diet, I understand. It is not a simple topic, and there are few cut and dry right or wrong answers.
I’ll try to provide some clarity on this confusing and often controversial topic.
Do Oats Contain Gluten?
In the simplest terms, no, there is no gluten in oats. Oats are more closely related to rice than to the grains containing gluten. Oats don’t contain gliadin or the gliadin-related prolamins (secalin and hordein) found in wheat, rye or barley that trigger gluten intolerance.
The protein fraction in oats, called avenin, may cause a cross-reaction in some people with celiac disease, but a wealth of research suggests this reaction only occurs in about 2% or less of people with a verified case of celiac disease and in about 5% or less of people with a verified case of non-celiac gluten sensitivity.
Yes, there are websites out there that claim otherwise, but the vast majority of doctors, dietitians, medical researchers and official celiac associations support this understanding.
Gluten Contaminated Oats
The real problem with oats, and the reason people are confused and unsure about whether or not to include oats in their diet, is cross-contamination.
Most oats are harvested and manufactured in a way that results in extensive cross-contamination with wheat. So most oats and products made with oats contain enough gluten to cause a negative reaction in people with celiac disease or a gluten sensitivity.
However, you can find reputable manufacturers who maintain strict standards while harvesting, packaging and labeling gluten-free oats.
Here’s a sample of manufacturers I’ve found reliable (although I can’t offer any kind of official guarantee):
- Avena Foods (Only Oats brand)
- Bob’s Red Mill
- Cream Hill Estates (Lara’s brand)
- Gluten-Free Oats
- Gifts of Nature
- Montana Monster Munchies (Legacy Valley)
These are manufacturers more likely to be found in North America. There may be others, but these are the ones I’ve either personally experienced or about whom I’ve heard good things from my readers. Please make sure whatever you buy is clearly labeled gluten-free.
Oats and Cross-Reactivity to Gluten
As I stated earlier, a percentage of people will still react to gluten-free oats. These individuals experience a reaction to avenin similar to the reaction they experience to gliadin, the main cliprit in gluten. For some reason, in these people, avenin triggers the same antibodies as gliadin.
For this reason, I recommend anyone diagnosed with celiac disease avoid oats for at least the first three months of their new gluten-free diet. I also recommend close supervision when you re-introduce oats. I’d prefer people have fresh blood work done right before they start eating oats again, then have follow-up blood work done about six to eight weeks after they’ve been eating oats. This way you may detect a rise in antibodies even before you experience symptoms.
Increased Fiber and New Fiber Cause Temporary Gas and Bloating
Keep in mind, re-introducing oats to a gluten-free diet may initially cause discomforts unassociated with an immune response to any proteins. Many researchers, doctors and celiac organizations recommend integrating gluten-free oats precisely because gluten-free diets often lack fiber.
But anytime you introduce a new high-fiber food into your diet, you may experience gastrointestinal discomforts like gas and bloating. If you never eat certain vegetables, then go out and enjoy a meal with a high volume of those certain vegetables, they will likely give you gas. This doesn’t always mean those foods are bad for you: instead it often means your body just isn’t used to those foods. If you ate them reglularly in moderate amounts, they might not give you gas. This is what may happen when you re-introduce oats.
Re-introduce oats slowly, with the understanding that some initial gas and bloating may occur. If you experience new gastrointestinal discomforts that last for more than two or three days, or more extreme symptoms, the problem may be more than a new fiber in your diet. At that point, stop eating oats and talk to your doctor.
What’s Sarah’s Recommendation?
As I said before, I believe patients starting a gluten-free diet after being formally diagnosed with any kind of gluten intolerance should avoid oats for at least the first three months of their gluten-free diet. I also believe they should avoid dairy products for at least the first one or two months.
Once you’ve experienced significant healing and relief, you can try re-introducing small amounts of certified gluten-free oats to your diet. Start slow, and gradually increase intake, but always eat oats in moderation.
I recommend adhering to the consumption principles outlined by the Canadian Celiac Association (in consultation with Health Canada). You can read their position statement here:
They recommend a maximum of 50 to 70 grams of oats for adults with celiac disease — that’s about 1/2 to 3/4 cup of dry rolled oats — and 20 to 25 grams of oats for children with celiac disease. Again, work up to these amounts. Don’t just jump in and consume this full amount if you’ve been avoiding oats for any length of time. And make certain they are certified gluten-free oats.
Monitor your symptoms and, ideally, only re-integrate oats under the professional supervision of a doctor or dietitian.
I know there are websites out there claiming everyone with celiac disease should just avoid all oats, including gluten-free oats. While I tend to lean on the side of better-safe-than-sorry, the vast majority of both the medical community and the official celiac support organizations disagree with this concern. This is because a vast majority of the evidence supports gluten-free oat consumption for a majority of people with celiac disease.
If you are confident you obtain enough healthy fiber and you are confident you have no nutrient deficiencies in your gluten-free diet — and remember, statistically speaking most people’s gluten-free diets are nutritionally deficient in some way — it may behoove you to just stay clear of oats. I’m not telling people to go out and eat oats.
However, most dietitians, medical researchers, doctors and celiac associations will recommend including a small amount of certified gluten-free oats in your gluten-free diet to increase your fiber intake and increase your nutritional diversity.
As always, listen to your body. If you are certain you feel better without oats and you are certain you’re fulfilling your nutritional needs without them, then don’t eat oats.