Treatment Guide

Why Oats Should Be Excluded from the Gluten-Free Diet

oats glutenThe suitability of oats as part of the gluten-free diet has been a source of controversy, with some groups pointing to research suggesting oats are safe and others pointing to other research demonstrating oats are dangerous to those with celiac disease. Close inspection of available medical research clearly shows that oats, even “gluten-free” oats, should not be included in the gluten-free diet at this time.

Until the early 1990’s, oats were excluded from the gluten-free diet, along with wheat, barley and rye. Then, a few pilot studies suggested oats may not cause the harm previously thought. The idea was proposed that people with celiac disease would find their diet more palatable, and would benefit nutritionally, if they were allowed to eat oats.

Heavy contamination of many oat products with wheat, rye, and particularly barley, was a concern. Companies began to produce so-called “gluten-free oats.” These oats were tested for the presence of wheat, barley and rye. They are vigorously marketed as “safe” for celiacs. However, studies show that even “uncontaminated oats” (oats not containing wheat, barley or rye) are toxic to an unknown number of people with celiac disease.

Early studies proclaimed oats to be safe, but they have since been judged faulty with poor validity. Nevertheless, they opened the floodgates to oat enthusiasts.

Opposing research followed, showing that “uncontaminated” oats activated disease in some subjects and proved that oat itself contains toxic sequences that activate the immune system, although to a lesser degree than wheat, barley or rye. Some groups tried to refute the clear evidence of villous atrophy with the feeble idea that oats cause bloating and pain in some patients due to its high fiber content.

The controversy over oat safety is not resolved because neither the long-term effect or the actual percentage of people who are intolerant are known. Large scale studies consisting of thousands of subjects are needed to produce valid answers. Such expensive research has not been undertaken to date.

Meanwhile, oat growers, millers and manufacturers actively purvey the notion that so-called “gluten-free oats” are safe. Packaging does not contain the caveat that oats are not safe for everyone, that they should not be consumed in amounts larger than ¼ to ½ cup per day, and that the patient should be closely followed by a physician to monitor changes to their health.


In 1995 a small pilot study from Sweden compared diet, with and without oats, in 52 adults in remission for 6 months and 40 newly diagnosed adult patients for 12 months.1 All the patients with new diagnoses were in remission at one year, except for one in the control group. Six patients in the oat groups and five in the control group withdrew from the study. Why did they stop eating oats? The study does not say, but concludes that “Moderate amounts of oats can be included in a gluten-free diet for most adult patients with celiac disease without adverse effects.”

In 2003, a study challenged 19 adults celiacs with 50 grams of oats over 3 months. One of the subjects developed partial villous atrophy and a rash during the first oats challenge. She subsequently improved on an oats free diet but developed subtotal villous atrophy and dramatic dermatitis during a second challenge. Five of the patients showed positive levels of interferon γ mRNA after challenge.2 Therefore, 31% of these subjects reacted to oats.

In 2003, a study showed that children with celiac disease have antibodies to oat proteins at significantly higher levels than reference children.3

In 2004, researchers studied the response to uncontaminated oats of nine patients with celiac disease.4 The nine patients were not a random sample. All patients had been eating oats, and four of them had shown clinical symptoms after oats ingestion. The goal of the study was to characterize the intestinal T cell response (immune system response) to oats in these patients, and to relate it to clinical symptoms and intestinal biopsy results.

The findings show that intolerance to oats exists at least in some patients with celiac disease, and that those patients have the same molecular reaction to oats that other patients have to wheat, barley, or rye. Of note: identical reactions to the subjects who had symptoms were also seen in two of the patients who did not have symptoms.

An article in WebMD advised physicians that oats are tolerated by most patients with celiac disease, but are not totally innocent. There are considerable differences between individual patients with respect to clinical and mucosal responses to gluten challenge.5


In 2007, a study showed that all the varieties of oats tested were immunogenic, with Lampton and Ava avenins inducing lymphocyte activation similar to that activated by wheat gliadin, while Astra and Nave avenins showed less immunogenicity, but still with a measurable effect.6

In 2011, a study showed that there is a wide range of variation of potential immunotoxicity of oat cultivars.7 It concluded some oat strains are more toxic than others.


In 2007, a study sought to verify the group’s earlier findings in 22 subjects tested after 6-12 months that oats are safe after 5 years’ consumption of oats by the same subjects, but their validity failed because of the high drop-out rate. Only 12 subjects of the original 22 actually finished the 5 year study period. 10 dropped out because “they felt uncertain about the safety of long-term consumption of oats.”8


Individuals with celiac disease vary in their immune reactions and symptom responses to gluten in wheat, barley, rye and oats. It is clear that oats are not a safe grain for all patients.

Prudence dictates that oats should be avoided until large-sample, long-term tests on oats are performed, strains of oats that do not elicit immune reactions are discovered, and tests that can accurately determine whether a patient reacts to oats become available.

On a personal note, my broad experiences with the gluten-free community reveal a sizeable number of individuals with celiac disease who do indeed react to oats in the same way they react to wheat, barley and rye. In speaking to gluten-free support groups, I would estimate at least 10% of people say they react to oats. Here are 4 examples from hundreds of my own interactions:

  • At the 2007 Food & Nutrition Conference & Expo in Philadelphia, an employee representing a popular so-called “GF oats” company appeared very ill and anxious. Her booth was across the aisle from our book booth where we were displaying my book, Recognizing Celiac Disease. During a lull in traffic, she approached me to speak. She described how, after having worked for this company the past 6 months and eating their oats, she felt the same as she did before her diagnosis. She said, “The only thing I changed in my diet is that I eat these oats.” Looking at the floor, she added, “This is my job.”
  • Before giving a lecture In Tampa, a man came up to me to ask why he still needed blood transfusions after being strictly gluten-free for more than 2 years. His attentive wife vouched for him. After I spoke, during which I advised the attendees not to eat oats, the wife said to me, “He has something to tell you.” “I eat oats, but the package says gluten-free.” When I asked how much he was eating, he admitted to eating 2 cups of these oats every morning.
  • A woman emailed to ask why her bloating and headaches continued on a strict gluten-free diet, eating only food labeled gluten-free. When she cut out the GF oats, these symptoms disappeared within the week.
  • Leaders of 2 national celiac disease organizations positively told me they cannot eat oats. Many local support group leaders say the same.


Please add your own experience as a Comment below.


1. Janatuinen EK, Pikkarainen PH, Kemppainen TA, et al. A comparison of diets with and without oats in adults with celiac disease. N Eng J Med 1995 Oct 19;333(16):1033-7.

2. K E A Lundin,1 E M Nilsen,2 H G Scott et al. Oats induced villous atrophy in coeliac disease. Gut. 2003 November; 52(11): 1649–1652.

3. Hollen E, Hogberg L, Stenhammar L, Falth-Magnusson K, Magnusson KE. Antibodies to oat prolamines (avenins) in children with coeliac disease. Scand J Gastroenterol 2003 Jul;38(7):742-6.

4. Arentz-Hansen H, Fleckenstein B, Molberg Ø, et al. The molecular basis for oat intolerance in patients with celiac disease. PLoS Med.2004 Oct;1(1):e1. Epub 2004 Oct 19.

5. Ciclitira PJ Ellis HJ Lundin KE. Gluten-free diet what is toxic?

Best Pract Res Clin Gastroenterol. 2005 Jun;19(3):359-71.

6. Silano M, Benedetto RD, Maialetti F, et al. Avenins from different cultivars of oats elicit response by coeliac peripheral lymphocytes. Scand J Gastroenterol 2007 Jun 8;:1-4.

7. Silano M, Benedetto RD, Maialetti F, et al. Avenins from different cultivars of oats elicit response by coeliac peripheral lymphocytes. Scand J Gastroenterol 2007 Jun 8;:1-4

8. Comino I, Real A, Lorenzo L, et al. Diversity in oat potential immunogenicity: basis for the selection of oat varieties with no toxicity in coeliac disease. February 2011.


9. Kemppainen T, Janatuinen E, Holm K, et al. No observed local immunological response at cell level after five years of oats in adult coeliac disease. Scand J Gastroenterol. 2007 Jan;42(1):54-9 .

Author Information: Cleo Libonati, RN, BSN
Cleo Libonati is a Co-Founder of Gluten Free Works, Inc.
She is the author of Recognizing Celiac Disease.
She can be reached by E-mail.

About Cleo Libonati, RN, BSN

Avatar photo
Cleo Libonati, RN, BSN is CEO and co-Founder of Gluten Free Works, Inc. and She is the author and publisher of the highly recommended celiac disease reference guide, Recognizing Celiac Disease.


  1. Carol@easytobeglutenfree

    Before I ever even heard of a gluten free diet I knew I had very obvious issues with oats even though I did not have such obvious issues with other gluten containing grains. I have not and will not eat oats even if they are certified GF.

  2. Thanks, Carol, for telling us your experience.

  3. That is very interesting. I came across a study that showed gluten contamination is also common in gluten-free grains and seeds. Even if an individual finds they can tolerate oats it’s possible they are contaminated. This I would think makes it very hard for someone to pin point what causes symptoms.

    Thank you for the great post. So mush informative detail.


    Gluten-free Labeled Grains May Contain Gluten

    Twenty-two gluten-free grains, seeds and flours, not labeled gluten-free, were purchased and sent to a lab for gluten content analysis . Products included white rice and flour, brown rice, corn meal, polenta, buckwheat and buckwheat flour, amaranth seed and flour, flax seed, millet grain and flour, sorghum flour, and soy flour. Gluten contamination of mean gluten levels ≥20 parts per million (ppm) was found in 32% of the samples (7/22), mean gluten levels ranging from 8.5 to 2,925.0 ppm was found in 41% of the samples (9/22) and 59% (13/22) of the samples contained less than 5 ppm for gluten. The authors point out that inherently gluten-free grains, seeds and flours are not gluten free and co-mingling can occur anywhere along the line from field to package. Some degree of contamination exists in naturally gluten-free grains.

    J Am Diet Assoc. 2010 Jun;110(6):937-40.
    Gluten contamination of grains, seeds, and flours in the United States: a pilot study.

  4. Good investigation, Sabra! Thanks, too, for the study link. Lots to think about here.

  5. Just wanted to add a link to a newer study:

    The researchers looked at several varieties of oat, using the G12 antibody to test them for gluten. They found that different varieties of oat have different levels of gluten in them, ranging from none to some (although even those oats with the most gluten have much less of it than wheat, it’s still enough to cause a reaction).

    The findings are helpful because they indicate that cross-contamination (in the field, or in processing) aren’t the only reason why some people have reactions to oat: some oats just aren’t gluten-free, period. Others contain little enough gluten to fall under the 20ppm guidelines, and still others no detectable gluten at all.

    Full disclosure: The G12 antibody is found in all GlutenTox products, and my company distributes GlutenTox Home in North America.

  6. I am gluten intolerant and cannot tolerate oats AT ALL. I only discovered this in my 20’s. Growing up, my dad would force us to eat a large bowl of oatmeal almost every morning for breakfast, thinking it was healthy for us. *sigh*

  7. I was biopsy-diagnosed in January and have been GF since then. I’ve never liked oatmeal and never ate it, but the scarcity of grains I could eat prompted me to give GF steel-cut oats a try. Not only is the the texture way better than rolled oats, I can eat them with absolutely no ill effects. I make my own granola using them, and enjoy a bowl of oatmeal with flax, pumpkin seeds and berries twice a week. Just MHO, but that’s been my experience.

  8. There are many studies that have been done which show that pure, uncontaminated oats are safe for the majority of people with celiac disease (adult and children)- examples include authors such as Sey, Koerner, Pulido, Koskinen, Guttormsen, Holm & Maki, Hogberg and the list goes on. If you have the internet go on to the pubmed website and simply type in “oats and celiac disease” and read the many abstract summaries of studies which show that pure oats are safe. One was published this month- June 2011. Yes, commerical oats are contaminated with gluten possibly because of the way they are grown but oats that are labeled gluten-free such as Cream Hill Estates or Bob’s Red Mill gluten-free oats are regularly tested for gluten content and found to contain <10 ppm. Oats that do not have a gluten-free label on them such as Quaker and McCanns are NOT safe for persons with celiac disease.
    Persons with celiac disease that do decide to introduce gluten-free oats should be on a strict gluten-free diet and should be followed regularly by their gastroenterolgist. The recommendation for adults is up to 50 grams of dry oats per day and up to 25 grams for children.

  9. There are many published studies on the safety of pure, uncontaminated oats for the majority of both adults & children with celiac disease. Go to the website pubmed and do a search with the key words oats and celiac disease.

    This article was just published in a very reputable journal…..
    JPEN 2011 Jul-Aug;35(4):459-64. Epub 2011 May 31.
    Prospective study of clinical and histological safety of pure and uncontaminated canadian oats in the management of celiac disease.
    Sey MS, Parfitt J, Gregor J.
    There were no significant changes in symptom scores, weight, hemoglobin, ferritin, or albumin during oat consumption. The tTG remained negative in all patients, and the histology scores did not significantly change during oat challenge. The only relapse occurred in a patient who became noncompliant with her gluten-free diet. Conclusion: The findings support the safety of pure, uncontaminated oats manufactured under Canadian Celiac Association guidelines for patients with celiac disease. PMID: 21628610

    Pure oats that have the gluten-free claim (such as Bob’s Red Mill or Cream Hill Estates) are very different from commercial oats that do not say gluten-free (such as McCann’s or Quaker). Commerical oats contain gluten because of the way their are grown. However, oats that say gluten-free are are tested for gluten content using ELISA tests (<10ppm). Pure oats are safe for the majority people- patients with celiac disease should speak to their gastroenterologist or dietitian about when and how much GF oats to introduce.

  10. Hi Cleo

    Thank you for your thoughts on the safety of gluten-free oats in the gluten-free diet.

    S Simpson has pointed out a recent article – the results of a small study recently conducted in Canada. I agree with you that it would be nice to have larger and longer-term studies in this area but as you know, research is costly and celiac disease doesn’t have the pharmaceutical companies associated with it who are often financial supporters of research. I think the area of variations in oat cultivars is an interesting aspect to look at for those of us in the gluten-free oats business.

    Health Canada completed a thorough review of the literature on the safety of pure oats in the gluten-free diet and took an official position, similar to the Canadian Celiac Association:

    You said: “Packaging does not contain the caveat that oats are not safe for everyone, that they should not be consumed in amounts larger than ¼ to ½ cup per day, and that the patient should be closely followed by a physician to monitor changes to their health.”

    You obviously have not seen our packaging where we have the following advisory on our package:

    Current scientific literature suggests that the majority of people with celiac disease can tolerate eating limited amounts of pure and uncontaminated oats, in the range of 20 to 25 g per day (65 ml – ¼ cup) dry rolled oats by children and 50 to 70 g per day (125 to 180 ml – ½ to ¾ cup) dry rolled oats by adults. There may be a small number of affected consumers who can not tolerate even pure oats. Proper medical follow-up is advised. Please check with your doctor and/or dietitian before introducing oats into your diet.

    Finally, we know there are people with celiac disease who do “react” to even gluten-free oats – is it the protein in the oats or something else? I don’t think we really know. Your figure is 10% react, I’ve seen 5-7% in the literature. Is it because they have celiac disease that they “react” or are they part of a sub-group of the general population who have difficulty consuming oats, just like some people can’t tolerate soya, corn, rice etc.

    Beth Armour
    Cream Hill Estates

  11. Interesting reading on the article and responses. I agree with both Beth Armour and S. Simpson that larger studies would be an advantage. As these are not available, it is also important to note that there are no long term studies that prove negative effects of consuming pure oats for those on a GF diet or what percentage of the Celiac population cannot tolerate pure oats. What we know is that a large percentage of people with Celiac Disease have been consuming pure oats for approximately the past 5 years, apparently without ill effect. This is not research, it is a fact.

    Oats offer fibre and nutrition which are lacking in so many gluten free foods. It would be a shame to take that away from those who can enjoy the benefits of oats for the sake of a small percentage who do not tolerate even pure oats. As Beth mentioned, perhaps they react to oats in a similar way as those who cannot tolerate soy, corn, peanuts or other foods.

    I represent Avena Foods, a dedicated gluten-free oat processing company which has given me the opportunity to speak with numerous people who are on a gluten free diet for medical reasons. Based on my experience the estimate of 10% is high. Health Canada’s statement acknowledges this small group of people and has set guidelines on how to safely incorporate pure oats into a gluten free diet:

    “Despite these limitations, the possible benefit for a larger group of individuals with CD warranted that Health Canada assess the currently available scientific data. This review concurs with the position issued earlier by the Canadian Celiac Association (CCA) that the majority of people with CD can tolerate moderate amounts of pure oats. When introducing pure oats into their gluten-free diet, Health Canada recommends that individuals with CD have proper follow up by a health professional, including initial and long term assessments. The amounts of pure oats should be limited to 20-25 grams/day (65 ml – or 1/4 cup dry rolled oats) for children and 50 -70 grams/day (125 to 175 ml – or ½ to ¾ cup dry rolled oats) for adults, as recommended by the Canadian Celiac Association.”

    On a personal note, I was diagnosed with Celiac Disease 21 years ago. I added pure oats to my diet 5 years ago and have been careful to follow up with my doctor to ensure no damage is being done to my gut. When I was diagnosed with Celiac Disease I was devastated at the loss of so many foods I enjoyed cooking and eating. Adding pure oats to my diet gave me the opportunity to once again enjoy many of those forbidden foods. To take away pure oats now would be just as devastating as it was to have all gluten containing foods taken away when I was diagnosed with Celiac Disease.

    Based on research, current R5-ELISA gluten testing methods, strict guidelines for growing and processing pure oats and personal experience, thousands of consumers agree that pure oats are safe within the limits as outlined above in the Health Canada statement. It is time for the regulations to catch up with the industry to allow gluten free labeling on products containing pure oats.

  12. Avatar photo
    Cleo Libonati, RN, BSN

    To Beth, representing Cream Hill Estates, and Tilly, representing Aveena Foods, who said, “It is time for the regulations to catch up with the industry to allow gluten free labeling on products containing pure oats”: Real hope for celiacs who want to eat oats is on the horizon. This hope does not depend on what labelling laws can get passed but on the truth of producing genuinely safe oats that can be tested as such.

    You are well-meaning Canadian businesses fighting for more than 6 years to get your “pure oats” labelled gluten-free in Canada while at the same time selling them as gluten-free here in the United States…my country. I am in the business of helping people get well and stay healthy living gluten-free based on facts.

    Your business is to package oats free of contamination from wheat, barley and rye. Therefore, you use the R5 ELISA testing method to identify and quantify wheat, barley and rye prolamins. As you know, this test cannot identify toxic oat prolamins, so the problem remains with oats. The REAL solution is to plant oat seeds that are genuinely free of toxic sequences. Research published this month has identified non-toxic oat cultivars and the test that can detect toxic oats to avoid their contamination. When you package these safe oats, we will be the first to buy and promote them.

    About labelling: Right now, you say that people eating your oats should be followed by a gastroenterologist because your oats are not safe for everyone. This is easier said then done. Only 5% of celiacs are diagnosed and many of them never saw a GI doctor. Therefore, they would not be followed just because they want to eat your oats. Whereas gut symptoms are an unreliable measure of detecting gut damage, nutritional testing for malabsorption is key.

    It greatly concerns me that few celiacs receive baseline nutritional testing, let alone follow-up, for this condition that ALWAYS causes malabsorption when activated. Actually, many people report to us that they are refused when they ask. Because we offer SpectraCell Nutritional Analysis, which identifies the actual status of 33 nutrients within white blood cells, we know that celiacs show a great variation of deficiencies.

    Unless oat eaters are nutritionally tested, it is silly to pretend that they are not damaged. Until non-toxic oats are commercially available, it remains prudent to wait.

  13. I was diagnosed with Celiac Disease via Biopsy 10 years ago. Unfortunately I cannot tolerate even Certified Gluten Free Oats.

  14. Thank you so much for writing this!!! I have gotten sick multiple times from gluten free oats. People need to know that they are not safe for everyone. I have eaten out a few times and had meals that were labeled GF on the menu only to find out later (after getting sick) that they contained these “GF Oats.” It is frustrating enough eating out!!! If we continue to misinform the public that these “GF Oats” are safe for celiacs than we are doing the community a disservice and more people will get sick by no fault of their own.

  15. I can not tolerate regular oats (haven’t been able to prior to going GF) – however steel cut oats I dont seem to have a reaction? I wonder what/if the protien structure is in these GF steel cut oats? Does anyone have any information on this? If I eat regular oatmeal, instant, rolled, quick cooking I always have extreme gastrointestinal response, I am not fun to be around. However, no such reaction to steel cut.

  16. It’s been a funny thing. It seems although I’m gluten intolerant, I can tolerate a small (less than a cup per day) of the “gluten-free” designated steel cut oats. However, I don’t seem to tolerate gluten-free oat flour, from any source, in any amount.

    Just another odd piece of the puzzle that never seems quite done…

  17. My daughter was diagnosed Celiac as an infant by biopsy and antibodies. She is very sensitive to gluten and has an obvious reaction within an hour or so of exposure. She is meticulous about her diet and it had been years since she had a reaction. This evening we tried a dish with a modest amount of Bob’s Red Mill Gluten-free oats (she may have consumed a 1/4 cup). She is now in the midst of a severe reaction. I believe any product containing “gluten-free” oats should come with a warning that not all persons with Celiac Disease can tolerate them. Companies that process “gluten-free” oats in the same facilities as other gluten-free products should also be required to disclose this on the label and warn about possible cross-contamination. Agri-business marketing needs should never trump the health needs of consumers.

    • Avatar photo

      Hi Doug,

      Sorry to hear about your daughter. Try Alka Seltzer Gold. It helps cut the reaction and lessen the symptoms.


  18. Phew. What a relief – after reading this article I am beginning to realise I was not imagining it: oats (and buckwheat) DO make me feel ill, bloated and hot and bothered. On days when I don’t eat them, I feel fine, my phlebitis settles down, I sleep well and I feel awake during the day. But when I breakfast on buckwheat and/or oats, I know I am in for a rough day. Tiredness, burning lower legs (phlebitis), and as for doing my jeans up – forget it. Too bloated.

    I only discovered my intolerance for gluten when I experimented by cutting out gluten for 2 weeks to see what would happen. I felt so ill I wanted to die the first 2 days, but after that I felt better than ever before. Two weeks later I tried some wheat, and hey presto: I felt ill, bloated and feverish within an hour.

    Then I discovered buckwheat and oats, having been reassured they were gluten free, but my health was still up and down. Now I know why. Goodbye buckwheat and oats, and hello lentils, brown rice, peas and beans!!

    (My GP thinks I am one of those hypochdriac internet nuts. But how do I explain I have lost 6 kilos in weight without any other changes in my diet, and my chronic constipation and pains in my liver area have completely disappeared!)

    • I have the exact same reactions as you to wheat, rye, barley and oats! Thank you for sharing. My doctor labeled me as hypochondriac, too, because my tests for allergies and celiacs are always negative.

  19. Thank you, Betty, for telling us your experience with oats…and buckwheat. So glad this article helped you improve your health and wellbeing!

    There is more to this grain business than meets the eye. You may be interested to view our articles on lectins. These tiny proteins are one thousandth the size of gluten but are also able to cause similar GI distress. In fact, before tissue transglutaminase enzyme was discovered 20 some years ago, lectins were thought to be THE CAUSE of celiac disease. To be sure, lectins add to the effect of gluten.

  20. It’s really a shame as I grew up on oatmeal and loved having it as part of a healthy and quick breakfast. I even emailed Quaker to ask about their oats and grits. You can read the response at my blog here:

    Thanks for the info!

  21. I don’t know what day I am into eating GF oats again, after not eating them for a while due to lack of money, and I can just say that right now, I feel like complete and utter crud. Its like eating wheat all over again. I feel nauseated, I get headaches, and not only that but within an hour and a half, I lose control of my bowels. Just. Like. Wheat.
    I can say now that I will no longer eat them, especially after reading this.
    Which really isn’t going to be fun since that is what I eat in the morning for breakfast.

  22. I am not on a gluten free diet yet. but My 15y/o son and myself always feel nauseous and get headaches after eating them.
    He has a stomach that is from him eating too much wheat and trying to find a growing teenager who grows faster than weeds in a garden is very difficult.

    he feels as if he isn’t full without his bread.

  23. I’ve had celiac disease for 21 years and I’m so grateful for all the gluten free foods that are now available compared to 21 years ago. I’ve tried, on several occasions, to see if I could tolerate gf oats and I’ve yet to be successful. My symptoms, although slightly milder than accidental gluten ingestion, are still very real and uncomfortable. My conclusion…I cannot tolerate oats. This being said, I wish GF companies would clearly state on the front of the packaging if oats are present. I’m already reading enough labels and now I have to read GF labels too.

  24. We started a gluten free, casein free diet about four months ago. We have an eleven year old autistic son. We’ve discovered that in addition to gluten and casein, he’s sensitive to preservatives, additives, food dyes, soy and corn products, and sugars also. We’re in the process of going organic for the entire family. We recently tried Bobs red mill gluten free oats that are certified gf and grow only in oat fields. Omg what a problem the oats have caused for our son! He regressed tremendously as if we had never removed gluten in the first place! We noticed a reaction within 2-3 hours! Prior to being gluten free, et. al. he would exhibit aggressive behaviors such as hitting, scratching, spitting, throwing, yelling/growling, and banging walls. Now he’s calm and doesn’t exhibit those behaviors anymore! After giving him the gf oats, we noticed SOME negative change in behavior but didn’t think much of it, however after the third day of eating the gf oats he was back into full blown meltdown mode /aggressive behaviors. After a day and a half of stopping the gf oats, he is calmer, happier, and back to communicating well rather than impulsively aggressing!

  25. I have not been diagnosed celiac but am about 95% gluten free, having only an occasiosional bite of noodles or something. I follow a paleo diet. Before I started I was eating oats for breakfast and always felt gassious afterwards but never had great pain. After I cut them out completely on paleo for 6 months or so, for some reason I decided to have them again for breakfast one day and immediately regretted my decision. I always measured out exactly 1/2 a cup so it wasn’t even a massive portion. But I felt like my stomach was going to explode and I literally curled up into the fetal position in bed for a couple hours. I suspect I have some gluten insolence in general, but for some reason, although I know oats generally are gluten-free, they seems to affect me much worse. I’ve never eaten them since. It’s just not worth it. Besides that I’ve lost the last 10lbs eating bacon and eggs every morning which is way better :) no bloating, no pain, no crying in the fetal position. :D

  26. As a celiac whose healing was thwarted for a year due to faithfully eating those GF oats, I would be very happy to see warning labels on the oats. Such a warning could have saved me that year of misguided (and expensive) grief. After serologic confirmation that oats were the culprit, I took all my remaining unopened GF oat products to give away at a local celiac support group meeting — and no one would take them! Every member of this group avoided all oats, and rightfully so.

    I fret that GF oat products, especially flour, will be used restaurants claiming to offer GF food — how can they know this is a problem if the dietary nutritional community is pushing it? It’s another unnecessary complication that threatens my healing. My local grocer has filled their GF section with GF oat products — rolled oats, granola, cookies, flour — because they have no idea what the subtleties of the diet are.

    The current “wisdom” on GF oats is very misleading, and will perpetuate damage for celiacs.

  27. I wonder if anyone has a similar issue to mine, it seems to be very rare, but I am violently ill aftereating oats – bloating, terrible stomach upsets, agonising cramps, headaches etc, but don’t really respond at all to wheat – it barely bothers me at all. What would I call this? Can I still be considered coeliac? I am not diagnosed with anything other than ibs, but I struggle with mild allergies to many foods such as raw fruits, nuts that have not been roasted, and soya products. in the past I’ve suffered from depression and chronic pain, as well as mild hormonal imbalances. No doctor has ever looked at the whole picture, but I can’t help but feel it is all linked somehow.

  28. Thank you so much for this article.

    I have not been diagnosed with Celiac due to the fact that I couldn’t finish my “Gluten Challenge” before getting tested. But I have been diagnosed with Gluten Intolerance.

    Since cutting out all gluten for months, I have not had single abdominal issue until Friday when I ate some “Gluten Free” muffins. I had three of them during the course of the day. Over the weekend my stomach issues worsened all the way though till Tuesday. This is a typical gluten attack of me. Everything else I ate over the weekend, I cooked myself.I couldn’t understand why I had such abdominal pain until I went to buy some more and the owner told me they are wheat free, not gluten free. They contained organic oat flour.

    Is it possible that a person with only gluten intolerance can be sensitive to oats, or only people with Celiac??

    • Avatar photo

      Hi Janine,

      Anyone can be sensitive to oats. Also, just because you were diagnosed with gluten intolerance doesn’t mean you do not have celiac disease, or would never develop celiac disease. They are not mutually exclusive.

      Hope this helps!


  29. I’ve been gluten free for years now and haven’t had any oatmeal in all of that time until this week. I’m on a diet and thought gf oats would be perfect for the diet. I ate a half pack of instant GF oats on Monday and was feeling a bit exhausted, but thought it was the diet itself. The next day, I had a full packet of oats and had raging diarrhea like I get with wheat. I still didn’t put it together, particularly since the episode was over with the diarrhea, unlike the days long issue I usually have with wheat. Yesterday, I ate two packets of the oatmeal and had the horrible mood swings and really scary mental symptoms (couldn’t remember anything, felt panicked, was in a massive fog), as well as getting hugely bloated. I’d searched through everything I’d eaten looking for hidden wheat. Blah. Clearly, oats don’t work for me.

  30. I have recently put myself on a gluten free diet without any diagnosis because my Dr would not do testing saying, “if you had celiacs disease, you would know it”. I have to try something because I am so tired of being sick. My mother was gluten sensitive and her sister, my aunt, had celiacs disease. My symptoms are very much like my moms and my aunts so I am desperate to get relief. I have been gluten free for only 9 days but already have not had a single episode with my stomach until today after eating a bowl of gluten free oats. I had already told my dr that oats make me sick but he said it is just the fiber and if I continue eating them I will get used to them. I am not so sure he is correct. I am more inclined to eliminate them from my diet as well.

  31. I’ve been eating gluten-free for over a month now. I am self-diagnosed as being gluten-intolerant. I have felt amazingly better since leaving gluten out of my diet. Today, I ate oatmeal. I made an assumption it was free of gluten. I feel just the way I felt 5 weeks ago before I stopped all gluten. My brain is foggy, I feel anxious and weak. I jumped online to read about oatmeal and found this website. There’s no doubt in my mind that oatmeal should be on the list of foods to avoid. I feel so badly right now. I hope I recover from it quickly. Thanks to everyone for contributing their experiences here.

  32. Avoid ALL oats. Gluten free makes no difference. I felt awful after eating bobs red mills gluten free oats. My stomach was a mess and they made me solo tired. Of all the grains out there oats are the worst for me.

  33. Hopeful someone can help me figure this out….I was diagnosed with Celiac Disease about 1.5 years ago. Prior to my diagnosis, I dealt with mild/moderate anxiety, foggy-headedness, and mild hair loss when showering- issues that I had no idea were related to CD. I was diagnosed largely to gut issues, but was thrilled when, a few weeks after going GF, my anxiety resolved 100%, my head cleared, and I no longer lost hair when showering. My anxiety has remained gone, ONLY returning if I was accidentally “glutened” – I am extremely strict, and have only been glutened in cases of cross contamination or at restaurants. Since approximately April, my gluten symptoms have been back. My gut is fine, but otherwise, unfortunately, I feel back to my “old self” – anxious, foggy-headed, hair falling out in the shower. I asked my doc to run another Celiac blood panel, which he did, thinking maybe I was getting glutened by something I wasn’t aware of. My numbers came back perfect, best they have ever been, so I feel like I have ruled gluten out. The ONLY thing I can think of is that in April I started taking Juice Plus (the veggie one has oat in it) as well as Vega shakes in the morning (gluten free as well, but has oat bran in ingredients). That’s sort of my main theory right now – I remember reading that oats can affect some Celiacs in a similar manner as gluten. I don’t think CC from oats is an issue, as my blood panel was perfect. I wonder if it’s just the oats themselves? I have cut oats entirely about 5 days ago, but still feel foggy headed and anxious. Anyone ever experience anything similar? So tired of the anxiety. Ugh. Thanks!

    • Avatar photo

      Hi MBL,

      Oats can affect people just like wheat, barley and rye. It usually takes longer for the oat symptoms to appear. Unless your doctor is giving you tests for anti-avenin antibodies (antibodies to oats) the results will not show a problem. Your symptoms sound like they are due to deficiencies. You can find them, and how to treat them at

      Hope this helps.


  34. I’m just discovering that eating oatmeal that I made in a crock pot with steel cut oats, is making me lethargic.

    I just ate a bowl with some nut milk, cinnamon and maple syrup. I’ve eaten these three things with other things besides oatmeal and have never had a problem.

    The other day I had oatmeal in the morning and felt lethargic about an hour or so after eating. But I wasn’t sure if that was the culprit as I had taken a supplement that could have also been the problem.

    Today I didn’t take that supplement but ate a bowl of the oatmeal for lunch.

    I have brain fog and can barely focus on reading. So I’m sorry if this was covered in the comments already.

    Thing is I can eat wheat. I can eat bread and pasta and not have this kind of reaction. But the only thing that I could be reacting to right now is the oats.

    So why would someone be intolerant to oats and not wheat?

  35. I have not been diagnosed with CD but have had gut issues since I was a child so I decided to go GF three years ago, after getting pregnant with my second child I began having severe GI reactions to GF oat ingestion. I thought maybe it was just a weird thing but well after I had her the sensitivity remained, becoming now, crippling. I had one bite of oats yesterday morning and have been in bed for more than 24hrs with extreme lower GI pain, I’m glad I found this article and am now going to get tested for CD

  36. I am on a gluten-free diet and I have been for three years now. I too, thought that oatmeal was a safe & healthy breakfast item. However, I reacted the same way that I react to my allergies to gluten, soy, dairy, and eggs. I was eating large amounts for a week (every morning), and my body was fatigued, sore to the touch, and my tendons would ache. I would also wake up with migraines, and would be in a lot of discomfort throughout the night. It is safe to say that I am one of the people who cannot eat gluten-free oats!

    • Avatar photo

      Hi Madi! You are not alone. Oats is not safe. Unfortunately, the symptoms are frequently much more mild than the other gluten grains and can take much, much longer to develop. I am glad you figured it out and hope you are doing well now. -John :)

  37. I am gluten intolerant. I stopped eating gluten before I was tested for Celiacs. I have tried short gluten challenges several times followed by testing. The tests always come back negative, but I know I cannot tolerate them, nonetheless. Wheat, rye, and barley all give me severe stomach pain and bloating, etc. I have the same reaction when eating oats, even certified gluten free oats. Every year I try again to eat them, but I always have the same reaction. Within days of eliminating them from my diet, I start to feel better.
    I did get tested for the DQ2 gene: I have one copy.

  38. I have been on a diet that incorporates oats every morning and I have had significant weight loss results with this diet. Recently over the past two weeks my pants hurt so bad I have to take them off before the end of the day because I am so bloated and the pain is increasing every day. Today was the first day the pain and bloating hit within an hour of eating my oats and I can’t even stand because of the pain and bloating. I was assuming it was the gluten free oats because it is the only logical explanation at this point but this article confirms it for me. Thank you for your research!!

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