The FODMAPs Study Does NOT Negate Gluten Sensitivity. No, Its Not All in Your Head.

Updated April 9th, 2015

There are many people who will tell you that unless you have been diagnosed with celiac disease, you do not need to take gluten out of your diet. This is simply untrue. However, in May of 2014, the same month that honors Celiac Awareness, there was a huge media blitz slamming anyone going gluten-free who wasn’t diagnosed with celiac disease. There were tons of inflammatory headlines such as: “Surprise! Gluten Sensitivity is Likely Bullsh*t” or “Your Gluten Sensitivity May Be All in Your Head” or “It Turns Out Gluten Sensitivity Is Fake.” There were also a number of dumbed-down videos published explaining that gluten is “just” a protein and nothing to worry about for the vast majority of us that do not have celiac disease. Even celebrities like Jennifer Esposito and John Stewart jumped on board the criticizing bandwagon, while food-writer, Michael Pollan proclaimed on Huffington Post Live that “gluten sensitivity is a bit of a social contagion.”

Suddenly everyone who was eating gluten-free was under public scrutiny! I heard of baggers questioning shoppers about why they bought gluten-free bread, and waiters asking patrons if they had celiac disease, when they ordered off the gluten-free menu.

But the media didn’t get it right. The gluten-free diet is NOT a fad. People are taking gluten out of their diets, because they’ve been to doctor after doctor, and have had test after test performed, only to be told they’re just fine. And yet, they don’t feel fine. So they’re testing to see if going gluten-free makes them feel better. And if it does, then why shouldn’t they go gluten-free? Even without a definitive diagnosis of celiac disease.

There is still so much to learn about gluten sensitivity, but just because we don’t know everything about this disorder, does not mean that its ramifications aren’t important.

The “gluten-free diet is just for celiacs” media frenzy all started with a study that was published in August 2013 by Biesiekierski et al. in Gastroenterology [1]. A small subset of the general population with Irritiable Bowel Syndrome (IBS), were put on a diet low in FODMAPs, a type of carbohydrate found in many foods, including wheat, for 7 days. They then re-introduced vital wheat gluten (isolated from the rest of the wheat), and found “no evidence of specific or dose-dependent effects of gluten in patients with NCGS [non-celiac gluten-sensitivity] placed on a diet low in FODMAPs.”

In other words, according to the FODMAPs study authors, there was no difference in symptoms between those volunteers who ate high-gluten, versus those who ate low-gluten diets.

However, there are several problems with this study.

  1. First off, the paper is poorly written, confusing, and full of apparent discrepancies. For instance, they challenged patients with high-gluten, which they called “carbohydrate-depleted gluten,” so that they could isolate it from the starchy part of wheat. Yet, the gluten they used still had 15.6% starch in it! Also the population of the study was a small sample size to begin with — 37 people at the start of the study and only 22 people by the end.
  1. The study only sampled people with IBS. They assumed that complaints of gluten sensitivity only occurred in people with IBS. Why couldn’t complaints of gluten sensitivity occur in people without IBS? In fact, a high prevalence of gluten-related disorders do occur extra-intestinally [2], [3]. So if even if perhaps the digestive complaints of the IBS group are not related to gluten, that doesn’t mean gluten sensitivity doesn’t exist! Maybe IBS patients’ gastro symptoms are FODMAPs-related and not gluten-related, but that doesn’t mean non-IBS people can’t have gluten sensitivity!
  1. They said if NCGS people were indeed gluten sensitive, then they should have had minimal symptoms on a gluten-free diet, but since they still had symptoms, then it must have been something other than gluten causing problems. Why couldn’t the patients be gluten and FODMAP sensitive? I am! The way that I react to gluten is much different than the way that I react to fructose/fructans/FODMAPs, yet I am sensitive to both. Furthermore, as I’ve mentioned before, the conventional gluten-free diet only truly heals a small percentage of celiacs. We know that gluten is the main culprit in celiac disease, but whether celiacs are sensitive to all grains, or there is cross-contamination at play, or there’s a leaky gut that hasn’t been solved, or other issues with dysbiosis, we don’t know yet. So it’s just as conceivable that the conventional gluten-free diet only helps a small percentage of GS patients as well. The lack of improvement for GS patients on a gluten-free diet is not proof that gluten sensitivity doesn’t exist!
  1. They tried to prove that it wasn’t gluten they were sensitive to, but to FODMAPs. Wheat is a FODMAP. So maybe those complaining of gluten sensitivity were not sensitive to gluten (the protein) after all, but instead to the starch part of wheat. I have also pointed out that there are portions of wheat beyond gluten that are problematic. In fact, in a reply to this study, another group of researchers suggested that Non-Celiac Gluten Sensitivity might be better named Non-Celiac Wheat Sensitivity [4]. So maybe something else in wheat is the problem, not necessarily gluten, for people who suffer from IBS. So what? For all intents and purposes, wheat, in some form or another, is causing them problems. The general population doesn’t care which part of the wheat plant. They certainly aren’t going to start going out and ordering soup with a side of gluten! I love when Mark Sisson says: “Sure, I guess some IBS patients can start doing lines of isolated gluten powder.” But most people are eating or avoiding wheat.
  1. They tested for antibodies to gliadin during the first week, but didn’t bother to do so in the 3-day re-challenge, for reasons they did not explain. They say that “only” one person responded with T-cell activity. But out of 37 people, split into 3 groups for each diet (high-gluten, low-gluten, placebo) that’s roughly 10%! About the same percentage of the general population that is thought to have gluten sensitivity! Now the number of antibodies may not be as high as those seen in celiac disease patients (as they pointed out), but we aren’t looking at celiac disease here. As I’ve discussed before, gluten sensitive patients can be found to have gluten antibodies. The study glossed over this little detail.
  1. They only tested for symptoms of gluten sensitivity up to 3 days after the ingestion of gluten. Then they concluded the study. Research has shown that onset of symptoms for people with gluten sensitivity can occur anywhere between hours and days of ingesting gluten [5]. One study reports IBS patients reacting as much as 9 days after ingesting wheat [6], and an FDA analysis saw as much as 14 days or longer [7]. Three days was simply not enough time, especially in such a small sample size, to see real symptoms develop. Personally, my symptoms occur about 5 days after eating wheat and remain with me for several weeks. So I would have fallen into the camp of people for whom “no evidence of specific or dose-dependent effects of gluten” were found. And yet, 2 days later, I would have been really feeling the misery. It is also known that the “time lapse between gluten ingestion and the occurrence of symptoms” in celiac disease can even take weeks or even years [8], so if any of these NCGS patients actually had latent celiac disease (which might fall under the umbrella of gluten sensitivity), this study would have overlooked that.

Finally, this isn’t really about the study itself, but its designers. I wonder if they didn’t let their bias affect their interpretation of their (poorly designed) research. They are the ones who developed the low-FODMAP diet, complete with cookbooks, a smartphone app, workshops for dietitians and a FODMAP-friendly food certification program. Their whole livelihood depends on the validity of the FODMAPs theory, so they have a lot to gain by bad-mouthing the gluten-free “craze.” In one video (about 55 minutes in), you can see the visceral disdain that Dr. Gibson has for gluten sensitivity. And that has unfortunately made him myopic in terms of what could actually be at play in the gut battlefield of IBS sufferers. Perhaps that’s why the study itself is so confusing. Could they be purposely using smoke and mirrors to make it difficult to dissect their work? Ok. Now the conspiracy theorist in me is coming out. But it does make you wonder.

Its too bad because I do buy into the whole FODMAPs theory, and I, of course, also know that the gluten sensitivity exists. What’s to say they can’t exist simultaneously (at least for some)?

Oh, can’t we all just get along?

As I’ve said before, I believe we may be getting far too deep into the semantics of trying to separate the gluten from the chaff, when we all would really be better off by just avoiding wheat altogether. If there is a silver lining in this study, it may be that perhaps more people will embrace a wheat-free diet and foods that are naturally wheat- and gluten-free, rather than relying on “gluten-free” processed foods, when we still don’t know how safe they are, and often what they’re even composed of. The final point is, if you feel better on a gluten-free diet, and worse when you eat gluten (aka wheat), you have your answer. It’s not all in your head. Here are the facts.


[1] Biesiekierski JR1, Peters SL, Newnham ED, Rosella O, Muir JG, Gibson PR. No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates. Gastroenterology. 2013 Aug;145(2):320-8.

[2] Hadjivassilou M., Sanders DS, Grunewals RA, Woodroofe N, Boscolo S, Aeschlimann D.  Gluten Sensitivity: from gut to brain. Lancet. Neurology. 2010. 9:318-330.

[3] Volta U., M. T. Bardella, A. Calabrò, R. Troncone, G. R. Corazza and The Study Group for Non-Celiac Gluten Sensitivity. An Italian prospective multicenter survey on patients suspected of having non-celiac gluten sensitivity. BMC Medicine. 2014. 12:85.

[4] Carroccio A, Rini G, Mansueto P. Non-celiac wheat sensitivity is a more appropriate label than non-celiac gluten sensitivity. Gastroenterology. 2014 Jan;146(1):320-1.

[5] Vojdani A, T. O’bryan And G.H. Kellermann. The Immunology Of Immediate And Delayed Hypersensitivity Reaction To Gluten. European Journal Of Inflammation. 1721-727 (2008).

[6] Carroccio A1, Mansueto P, Iacono G, Soresi M, D’Alcamo A, Cavataio F, Brusca I, Florena AM, Ambrosiano G, Seidita A, Pirrone G, Rini GB. Non-celiac wheat sensitivity diagnosed by double-blind placebo-controlled challenge: exploring a new clinical entity. Am J Gastroenterol. 2012 Dec;107(12):1898-906.

[7] Food & Drug Administration, Office of Food Safety, Center of Food Safety and Applied Nutrition. Health Hazard Assessment for Gluten Exposure in Individuals with Celiac Disease: Determination of Tolerable Daily Intake Levels and Levels of Concern for Gluten. May 2011. p. 32.

[8] Volta U, et al. 2014.


  1. Hear Hear! Thanks for a great blog Heather! It is sad that hostility towards people who are different is expressed this way. At the IBS Treatment Center we do testing to measure immune response to foods and find that both wheat and gluten reactions are more common that just celiac disease. Patients do experience a wide variety of symptoms. And changing your diet for just a week or two is very often insufficient to see any change in symptoms.

  2. Rick

    This is an interesting article and interview. Whenever I talk to people about my Celiac and how I have to eat gluten free I usually get the response, “I should probably go gluten free, it’s so much healthier”. When really in fact it is not. Michael Pollan has a valid point regarding the amount of processed garbage out there that is usually loaded with soy and we all know soy comes with its own line GI issues. There is absolutely NO shortage of breads, cakes, cookies and whatever other items to fix the sweet tooth. Where the problem falls is with finding healthy, well balanced SAFE gluten free meals away from home. Safe gluten free meals in restaurants is very difficult to find, sadly I know. The problem that I am faced with as a Celiac is that there are A LOT of gluten free people out there and most of them wouldn’t have a problem with a meal if they simply plucked the bread off the top before serving or if the kitchen used the same knife to cut the bread and their grilled chicken. So many establishments and customers think just as long as I am not eating bread, pasta or dessert I will be fine and that may very well be the case. But for people with Celiac the stock or tomato paste used in a dish, be it not bread, contains a lot of gluten. So businesses see this and think just as long as there’s no bread it is gluten free, no the case when I learned the rice I was served was not gluten free because the way it was prepared. I am not trying to discount the fact that people do have problems with gluten who are not Celiac, but at the same time there are many who have simply jumped on the bandwagon because some movie star said so and now they removed breads and pasta from their diet and they all feel great. Those are the people that spur this kind of interview and headline statement and do the people with true gluten sensitivities and Celiac zero good.

    • Thanks for your comment, Rick. I totally hear what you’re saying. But in fact, we don’t know how much gluten is safe for the gluten sensitive, either. I fall into the NCGS camp. Whether that’s because I stopped eating gluten ten years before any doctor was willing to test me for Celiac, and thus results were non-conclusive, or because I stopped myself from developing the disease as soon as I was aware that gluten was making me sick… we can never know. But I can say that without a doubt, that the tiniest bit of gluten is no good for me. I cannot have gluten in stock or tomato paste or on grilled chicken, without getting very sick. Eating out at restaurants is very difficult for me.

      So I really believe that the truly Gluten Sensitive and Celiacs are in the same boat. Now everyone keeps talking about those who have jumped on the bandwagon just to be cool or to “feel better”, but I don’t know who those people are. The only people that I meet that are gluten-free both online, and in the 3-dimensional world, are choosing gluten-free because gluten (or wheat) is truly making them sick. Why else go through all the trouble? Maybe they are not well informed, so when they go to a restaurant and pick the croutons off, they may not realize that they could still get sick. In fact, how would they know, if most doctors tell them they’re fine and no one has informed them on cross-contamination and the safe thresholds of gluten (which I believe is zero)?

      When an article like this comes out, us Gluten Sensitive fare the worst. Because we don’t have an official diagnostic test that proves that we have a problem with gluten, even the Celiac community starts to turn their back on us, too. This is why I love Karen’s plea to stop all the bickering, as well as Dr. Rodney Ford’s follow up comments on the post. There is so much we don’t know about Gluten Sensitivity. But I know for me, and countless others that I’ve met both on and offline, that it is a real, and a serious condition. Not any less so than Celiac Disease. Just a little different.

  3. Rick

    Heather, I completely agree with what you said and that this is very real problem for us.

    These are just two of several experiences I have. Just the other day there were two women at our local HEB that we very overweight looking at the same old limited Gluten Free selections, they started asking me questions. I must have looked like I knew a lot about Gluten Free. I gave them my suggestions on products and where they were located in the store. I also told them about places outside the store where they can find Gluten Free products as well. I also told them about the smart phone app “Find Me Gluten Free” (which in my opinion is way under utilized here in Houston compared to other cities) and they were both very appreciative. They also told me they wanted to “try” Gluten Free because they had heard it was healthier. It is absolutely healthier for the people with sensitivities and Celiac but not necessarily for everyone, it is still a cupcakes, brownie or loaf of bread.

    There was another time when I was at a friends birthday party which was being held at Maggianos, partly because of me, so that I could attend and enjoy myself and there had to 16 of us (something else local businesses don’t realize, if one person has sensitivities or Celiac in a big group they’re the ones choosing the restaurant ). As we all know once people in group find out you have Celiac Disease everyone has story, “my (insert anyone) has Celiac” or “I’ve have a problem with gluten as well, I think”. Whenever someone says “I think I have a problem” I ask have you been to see a doctor and 9 times out of 10 the answer is NO. So at this birthday party there was a “I have a problem gluten as well”, this same person did not ask to have the chef prepare a safe GF dish, instead she had what everyone else was having after the conversation we just had! She said sometimes she “cheats”. Last week I had rice that I shouldn’t of had and I was sick as dog for two days, there is zero room for people like us to cheat. But the problem is this, people hear and see this and start assuming it is all in their heads or they read someone is promoting it and now they feel they need to follow this diet or at least when it is convenient for them.

    My point in all this, while yourself as well as Doctor’s are seeing real cases which I am NOT at all disputing, I am seeing the other side. I am seeing the people “trying it” or telling me they “have issues” while they are eating a bowl of pasta or dipping into something that has been cross contaminated. These are the people that give fodder to naysayers or critics of fad diets.

    Thank you very much for the time and effort that is being put into providing awareness and being source of great information to those dealing gluten issues.

  4. When I meet people like that, I tell them that eating gluten-free could be healthier – if done right! Simply replacing their gluteny foods with gluten-free foods may not be doing them any good. Maybe going gluten-free could help them – we don’t know their situation, so I feel like its our job to help educate them, since often times, doctors don’t believe in Gluten Sensitivity or won’t test for Celiac Disease unless the patient meets specific (often outdated) criteria. But “education” has to be done lightly.

    Here’s another example. I met a very unhealthy woman who has Celiac Disease, but goes out often to “party” or whatever with her friends and deliberately eats whatever she wants (aka gluten). She justifies it by taking a shot of Vitamin B12, because she says she also has pernicious anemia. I was shocked when she told me this. But what could I say: maybe you could fix the anemia, if you stopped eating gluten? Maybe you could get a lot healthier if you stayed away from gluten altogether? Its a lifestyle choice she is making, and I have no business telling her its not a wise choice.

    It does get frustrating sometimes seeing people deliberately hurting themselves, or unknowingly hurting our cause by trying gluten-free “now and then”. I think the recent boom in gluten-free menus and food products is like two steps forward, one step backward. We’ve raised awareness. But there’s still lots more work to do.

    Thanks for your kind words. I do hope I’m helping somehow. 🙂

  5. The difference between non-celiac gluten sensitivity and celiac disease is like the difference between osteo-arthritis and rheumatoid arthritis: One is a joint/connective tissue condition, and the other is an autoimmune joint/connective tissue condition. No one would suggest that osteo-arthritis “isn’t real” or “is all in your head” because it’s not autoimmune.

    It’s time to stop dissing NCGS.

    Just because the gluten-free diet is faddish does not mean that it is not a valuable, life-saving tool for many.

    You make some excellent points about the shortcomings of the FODMAPS study, Heather. I agree with all you say.

    Gluten sensitivity, whether it’s autoimmune or not, causes lots of bodily dysfunction, some of which is not usually connected with gluten. For example, hormone disruption, bipolar disease, depression, anxiety, schizophrenia (once commonly called “bread madness”!), neuropathy, auotimmune and non-autoimmune thyroid disorders, fibrocystic breast disease, ovarian cysts, migraines, menstrual dysfunctions, and more can all be caused by gluten in those who are sensitive.

    One week off gluten will not resolve these conditions.

    Some of them require a year or more to heal once glutens/grains have been removed from the body. “Cheating” sets back the healing process – and may undo it entirely – meaning some people never do heal.

    This is not the fault of the gluten-free diet. This is the fault of the patient, the patient’s family/friends, and society for not taking the condition seriously.

    In the end, the patient must be responsible for his or her own health, taking whatever precautions that are possible while still living a relatively normal life. Accidental poisoning is a completely different issue from “cheating” (“Just one bite won’t hurt me” or “I’ll just be ‘extra-good’ next week”). Going gluten-free can fix lots of issues, but it can’t fix stupid.

    As for testing, there is a genetic test for gluten sensitivity. It does not require you to consume gluten in order to determine whether sensitivity exists.

    I bought mine through Dr. Peter Osborne, a functional medicine doctor in Sugarland, Texas, who is himself gluten intolerant. He also has an excellent website aimed at laypersons that discuss peer-reviewed journal articles showing a connection between gluten and many disease processes. His site is

    You can sometimes get the same test through a local clinic or hospital, but in my case it was cheaper to order through him than to have the clinic order it in.

    Thanks for a great blog article, Heather!


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