Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
5 Sep

How Common is Gluten Sensitivity?

I’ve long suspected that everyone has some degree of sensitivity to gluten, even if they’ve never been formally diagnosed and even if they don’t notice any overt symptoms after eating it. Now we have concrete evidence that non-celiac gluten sensitivity actually exists. My own story was that of a lifetime grain-eater who defended my “right” to eat grains until I was 47 – until the evidence was just too overwhelming to ignore. Once I gave them up as part of a 30-day experiment, lo and behold, my arthritis cleared up, my lifelong IBS went away, and my occasional GERD disappeared. Ditching grains, especially wheat, changed my life for forever and made me understand how easy it is for so many people to overlook this possible problem. A recent study, which I highlighted in Weekend Link Love, confirmed the existence of non-celiac wheat sensitivity. Subjects without the atrophied villi (tiny projects that line the intestines and help absorb nutrients) characteristic of celiac and without positive tests for various markers that indicate celiac experienced gluten-related symptoms after a blinded wheat challenge. It doesn’t give us much of a clue as to the prevalence of sensitivity, but it establishes that such a thing might exist among the general population.

It’s not even the only study. It’s just the latest of many to establish and/or hint that non-celiac gluten sensitivity exists:

But how prevalent is it? We know that celiac disease is on the rise; what about gluten sensitivity?

First, before we get into numbers, let’s go over the difference between celiac and gluten sensitivity:

Celiacs have persistent and profound perforation of the intestinal lining (at least as long as they’re eating gluten) as well as atrophy of the villi, thereby allowing foreign proteins – including, but not limited to, gluten – constant access into the bloodstream and impairing nutrient absorption. Folks with “mere” gluten sensitivity have transient and milder intestinal permeability, or sometimes none at all.

Celiac is an autoimmune disease that inspires the immune system to attack the body’s own tissues, while in gluten sensitivity, the immune attacks are directed solely against components of the diet (gliadin).

Celiac disease seems to involve the “adaptive immune system,” while gluten sensitivity involves activation of the “innate immune system.”

In celiac, the inflammatory cytokine IL-17 is elevated. In gluten sensitivity, it is not.

So gluten sensitivity and celiac disease are two distinct “clinical entities” with the same environmental trigger – gluten – and many of the same symptoms:

  • Diarrhea
  • Bloating
  • Abdominal pain
  • Eczema
  • Headache
  • Foggy brain
  • Fatigue
  • Depression
  • Joint pain
  • Numbness in the extremities

And sometimes the symptoms aren’t obviously connected to gluten (or anything you did or ate). It’s tough to ignore persistent diarrhea that precipitates (pun intended) upon gluten ingestion. That’s an obvious symptom that may clue you in, especially if you’re aware of the potential problems with gluten, you’ve just eaten something containing it, and you’re pondering all this while filling the toilet. But gastrointestinal symptoms don’t always present themselves in gluten sensitivity, as in this study, where 13% of subjects with gluten ataxia (a kind of neuropathy) had no GI symptoms. I mean, who hasn’t felt brain fog from time to time, or been tired in the middle of the day, or had some itchy rashy red skin, or had sore joints before? Most people would never think to link these to the bagel they just ate (ok; you guys might).

Testing for gluten sensitivity is tough because there’s no real standard yet. You’ll notice that the recent study didn’t determine gluten sensitivity solely by running patients’ labs and looking for a certain figure; they had to painstakingly and laboriously eliminate confounding variables (like celiac) through extensive lab testing, and then run a double blind wheat challenge to see if symptoms still arose. That grand, single overarching lab test doesn’t exist, not yet anyway.

Well, that’s not exactly true. There are tests that measure the presence of anti-gliadin IgA (a gliadin antibody) in the blood and in the stool. Antibodies in the blood mean that gliadin made it through the intestinal lining into the blood, where the body mounted a defense against it; antibodies in the stool indicate the presence of antibodies in the gut, where the body has mounted a defense. Gut antibodies, however, come before blood antibodies. For that reason, fecal antibody tests are regarded as more accurate for testing gluten sensitivity, because blood antibodies only show up after significant intestinal damage has allowed gliadin to pass through. You could test positive for fecal antibodies and negative for blood antibodies if your intestinal lining remained fairly intact.

One study found that around 12% of healthy people’s blood samples tested positive for antibodies to IgG. Fecal tests, however, indicate that around 29% of healthy people test positive. If the fecal antibody tests are accurate and reflective of gluten sensitivity, that’s nearly a third of Americans!

There’s also a genetic component to gluten sensitivity and celiac, the HLA-DQ gene. According to some reports, almost every permutation of the HLA-DQ gene is associated with some manner of gluten sensitivity, particularly the haplotypes HLA-DQ2 and HLA-DQ8. Only HLA-DQ4 has never been linked to any form of gluten sensitivity, and less than 1% of the American population possesses a homozygous HLA-DQ4/4. If that holds true, then the vast majority of Americans have the genetic potential toward gluten sensitivity.

Of course, when you consider that everyone – regardless of genetic proclivity toward autoimmunity – releases zonulin, the regulator of intestinal permeability, when our intestinal lining is exposed to gliadin (a component of gluten), a universal response to gluten looks likelier. Sure, we all know plenty of people who can eat a sandwich without complaining, or that guy who claims he could never live without wheat. Gluten and related fragments may be getting through the intestinal lining in these people, but their immune systems mop them up pretty handily before they can do much damage. But what happens if their immune system is impaired, maybe because of a period of chronic stress or overtraining? What happens if their microbiomes are ravaged by antibiotics and poor diet and thereby absent the bacterial species necessary to fully degrade gluten? There’s no clinical trial tracking the effects of usually healthy people undergoing chronic stress or antibiotics on their sensitivity to gluten, but people are stressed, people are overworked, and their guts are messed up. It’s hurting our health in many different ways, and I wouldn’t be surprised if there is a lot more undiagnosed gluten sensitivity out there because of it.

It’s conceivable that gluten could be doing damage and causing constant, low-grade inflammation without you even knowing it. This is why folks who go Primal and give up wheat and other gluten-containing grains become more “sensitive” to wheat upon reintroduction. It’s not that going Primal has suddenly made them intolerant of gluten; it’s likelier that going Primal has made them more sensitive to their gluten sensitivity. It was probably always there, but they never knew what they were feeling until they removed it and then tried to reintroduce it.

As for figuring out if you’re gluten sensitive, I suppose you could go for one of the stool or blood tests provided by EnteroLab or Cyrex Labs (although not everyone is enamored with EnteroLab). But honestly? The gold standard is to just not eat gluten for a few weeks to a month and then reintroduce it and see how you feel. If any strange symptoms pop up (see list above), you’re probably sensitive to gluten. If you want further clarification at this point, then go for the tests. Just try the diet first. It’s gonna be your best (and probably the only necessary) lens.

We don’t have any real solid answers, sadly, just hints. But isn’t that how questions of human physiology tend to play out? It might be 12%, or maybe 30%, or perhaps even a higher (or lower) percentage of the population. Whatever the number, I know that grains don’t serve me well, and they probably aren’t doing you any favors either. So try giving them up for 30 days and seeing how you feel. After all, you aren’t missing out on anything nutritionally by avoiding gluten, except for some potential nasty health issues down the line.

That’s what I’ve got, folks. What do you think? Are you gluten sensitive? Let me know in the comments, and thanks for reading!

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. I was diagnosed with dermatitus herpetiformus 3 years ago. Eating gluten causes me to itch a lot and get spots on my body, not disimilar to knat bites. The doctor advised me to follow a gluten free diet. Occassionally I’ll have a flair up, but on the whole, gluten free has helped.
    My partner has diabetes and we have been reducing his carb intake for the last 2 months (since i found Mark’s daily apple). He hasn’t cut grains out, only down, and his glucose levels still aren’t down to 5, but he had less wind and we’ve both lost some weight.

    Suze wrote on September 14th, 2012
  2. Hi, I am a human with the usual human sensitivity to gluten. Also I cannot deal with any type of insoluble fibre. I am hypoglycaemic too.Bummer. I have been gluten+ sugar free for 2 months. I am almost symptom free(tada)including no more Hypoglycaemia! However, I am reaaaaaaally struggling with getting enough carbs in to me as I run about 20-25 miles a week. Please can anyone help me with some links to food ideas as there are really only so many bananas one can consume!

    Gema wrote on September 19th, 2012
  3. Not until my rheumatologist suggested I might be sensitive to gluten did I even consider it. I went Primal about a year ago and recently started to eat things I shouldn’t. Now that I started to eat primally again, many of the symptoms of gluten sensitivity have come back. My doctor and I was discussing the other day about this whole issue of gluten and eating properly while ditching certain foods. I told her that when I eat right, my symptoms almost go away. She said that she has heard that so much lately that she is going to start researching this because there must be something to it. Hmmmm…

    Kevin wrote on October 16th, 2012
  4. im 99.9% sure it’s a gluten intolerance. after a month of paleo, i ate ‘regular’ this weekend when i was out of town (carbs and everything) and ALL the symptoms came back. that’s no coincidence! funny story though-when i went back to my doc to ask for the IgG blood test today just to be sure, he said they didn’t even do it, because it’s not common! he prescribed me a medication, ordered another test, told me to visit my GI and took two tubes of blood from me for a CBC test, just for fun. total WASTE of time and energy. im happy to know im not the only one with these issues, because i walked out of there feeling so abnormal.

    Stephanie B wrote on October 29th, 2012
  5. I used to own and operate a dental ceramics lab, and for some 10 years or so, I suffered on a daily basis from a morning “sinusitis” that would have me draining an unstoppable amount of nasal liquid for around 5 hours every day. It got to the point I used a t-shirt as a handkerchief.

    To me it was “obvious”. I was allergic to one of the many powdered stones or any other of my dental lab materials. I was wrong.

    I learned about gluten, started a gluten free diet and in a few days the problem was solved!

    It has been almost 3 years of a gluten free diet for me, and the same amount of time the problem disappeared.

    Gluten in our diets is a health wrecking enemy. It is a cellular toxic molecule, specially today with the new genetically modified varieties of wheat and grains allowed into the market.

    I found this website today. I have spent a couple of hours reading it, and is great to find a person with which I can agree on in so many things.

    I am subscribing now! :O)

    Arnaldo wrote on November 10th, 2012
  6. G’day, YES! I do believe (through my own experiences with gluten) that the human body was not designed to eat gluten (wheat, rye, oats etc)
    I had been plagued with VAGUE symptons and general feeling of ill-health almost all of my life (I even had an internal examination by keyhole surgery to determine why I had constant stomach pains (like appendicitis – only I had it taken out years before (it very nearly burst – another indicator of gluten sensitity??)
    Then, for one reason or another (mostly lack of money – student days) I stopped eating bread and other processed things didn’t drink milk or use dairy products – just ate what is now called a primal plan of eating – and I was as fit as a fiddle and twice as healthy.
    To cut a very long story short, life happened and not knowing that I was on the right path of eating, I slipped back into everyone’s way of eating and finally ended up vomiting all night because I had eaten fish with batter supposedly made with corn(maize) flour but containing wheat instead.
    Twice more I had this problem before I FINALLY came to realize that both gluten and dairy were a problem for my body. I have been medically diagnosed with both gluten and lactose intolerance- since then I have done my utmost to avoid them both.
    AND I feel sooo much better.
    Hope this general info helps someone else.

    peggywh0 wrote on November 12th, 2012
  7. wow, lots of comments on this subject! here’s a little something that mark missed: there are many studies out there that suggest all auto immune disease is gluten related. i have hashimotos. i suspect i also have celiacs. i gave up the wheat because of my thyroid and lo and behold, all of my gastro-intestinal problems vanished, along with my joint pain. i eat a mostly paleo diet now but i do indulge occasionally in a gluten free treat. i find though, that my body is not happy with any grain product. i just don’t feel right after my indulgence.
    i believe there is a very recently published study (JAMA?) where a definitive link between blood type and diet has been established. us O types do best on a hunter gatherer diet, it’s not “just theory” anymore. that is 40% of the human population! also, most people who suffer from auto-immune disease have an O blood type. it’s a no-brainer for me, grains are just bad business for a huge chunk of the population.

    allison wrote on November 19th, 2012
  8. I have been gluten intolerant for 5 months now. The symptoms just starting slamming me so hard that I had no choice but to stop eating it. Every time I did eat it I couldn’t stand up or stay out of the bathroom it hurt so bad. My husband offered to go on a gluten free diet with me so that we didn’t have any contamination issues in the house for me. Now if he tries to have a sandwich while out on a job or whatever, he experiences discomfort as well. So he’s staying away form it all together. And we’ve realized that some people are just not tolerant of this. My father in law thinks this is just in his head and he really can eat gluten, he just is delusional and thinks he can’t. And we have explained over and over what gluten intolerance is, and if I eat that sandwich I’m going to be in a lot of pain and in the bathroom. He still just doesn’t seem to get it and nags my husband to eat gluten, even though he’s said time and time again that he can’t. Any one else have this problem??? If so how did you get them to understand?

    Cassy D. wrote on December 8th, 2012
  9. Interesting blog post on gluten and similar proteins in grains and grasses, gets a bit techie but fellow nerds may enjoy :)

    NorthernMonkeyGirl wrote on December 12th, 2012
  10. You really make it seem so easy with your
    presentation but I find this matter to be really something that I think I would never understand.
    It seems too complex and extremely broad for me. I am looking forward for your next post, I’ll try to get the hang of it!

    hivescure.webs.Com wrote on January 6th, 2013
  11. I have been gluten free for 4 years and palo for 1 yr. I just havent seem to healed and going paleo helped but I took a food allergy test and it showed me still reacting to gluten even though I havent had it in over 4 yrs unless by accident and some other sensitives now. My doctor wants me to do the rotation diet the problem is it has legumes, bread in it which I dont eat so I cant get enough nutrients or protein right now. any advice or actions that you would recommend. I do know I am intolerant probably celiac .. from eliminating gluten.

    connie curtis wrote on January 28th, 2013
  12. I’ve been trying to do a gluten free diet for about 1.5 years. I haven’t done a perfect job–but have tried to stick with it. I’ve struggled with a lot of inflammation issues–IBS, tendonitis, Psoriasis, PCOS, unexplained infertility and an inability to lose weight even with exercise. I quit gluten AND milk (but not all dairy.) I lost 40lbs in 5 months. My ovarian cysts disappeared. My regular cycle returned (had been truly gone for 2-3 years.) My skin got better. I felt better. When I ate gluten again over the holidays, I gained weight, my tendonitis returned, I became sluggish–a lot of negatives. I’ve been off gluten again for about a month–lost weight, inches, feel great. Tried a sandwich yesterday & today with wheat bread–my skin is now burning, I’m tired and recommitted to my gluten-free lifestyle. Just not worth it…

    My gastro did the celiac test and I came back negative. I’m thinking I am gluten sensitive–whether or not a test can catch it–the symptoms are there.

    Jennifer wrote on February 10th, 2013
  13. Thanks for finally writing about >How Common is Gluten Sensitivity?
    | Mark’s Daily Apple <Loved it!

    NESN wrote on March 11th, 2013
  14. I can’t say for sure I may be gluten intolerant or not, but I do know many of the typical symptoms you share here that I experienced on a pretty frequent basis are not so prevalent to me since I have been going primal for over a year now.

    I do see that on those times I overdo the carbs (donuts) I see the reaction pretty quick. Just a good reminder to watch what I eat closer.

    Mark A. Michael wrote on June 10th, 2013

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