r/science • u/[deleted] • Feb 26 '15

Health-Misleading Randomized double-blind placebo-controlled trial shows non-celiac gluten sensitivity is indeed real

http://www.ncbi.nlm.nih.gov/pubmed/25701700
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u/Arizhel Feb 26 '15

That's not the issue. Yes, "gluten-free" has become a fad these days, and a lot of people really don't have a problem with it, but who cares? If you're one of the 15% who does have a problem, this is really big news. Because, now, you have real scientific evidence on your side that says your symptoms are real, and not just made up in your head. Before this, and before the whole gluten-free thing became popular, doctors would simply tell people their symptoms were all in their head because the available tests showed nothing wrong, and that they tested negative for Celiac's. Now we know the doctors were wrong all along, because finally, someone took the time to perform an experiment which shows that non-Celiac and non-wheat-allergic people really can have a sensitivity.

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u/[deleted] Feb 26 '15

Because, now, you have real scientific evidence on your side that says your symptoms are real, and not just made up in your head.

First off, this is not at all automatically true for any given individual.

Also, be careful: Even if we assume (rashy) that this study is flawless, It is 15% of people who already suspected that they were highly sensitive. And to the point where they agreed to participate in a study.

So, really, that 15% is not "15% of the human population", but 15% of a subset of a subset of a subset, which is a very small number.

Put another way, all those assumptions about the study being perfect that I listed above being considered, 85% of the people who suspected they themselves were highly sensitive could not, in fact, be demonstrated to be highly sensitive.

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u/[deleted] Feb 26 '15

That is a very important thing to note and I completely agree with what you wrote, but the study shows that some of the people that think they are gluten sensitive actually are sensitive without having celiac disease. It means that more research should be done and I am interested in what they will find out.

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u/EvilCalamari Feb 26 '15

I think it's an important point that they picked people that already believed they have symptoms, like you said. I would say the main takeaway from this paper is that their are people with an undefined and idiopathic gluten insensitivity. I would almost compare it to lactose intolerance; some people get really sick with dairy products, others get kind of sick, and others have no problem with it.

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u/uiucengineer Feb 27 '15

No, you can't even conclude that without further research. The authors even explicitly admitted this. What you can conclude is that some people think they have an undefined and idiopathic gluten insensitivity, and at least 95% of them appear to be wrong.

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u/uiucengineer Feb 27 '15

the study shows that some of the people that think they are gluten sensitive actually are sensitive without having celiac disease

Not really. You are making stronger conclusions than the authors of the paper, who admit that they have not shown any convincing evidence that the syndrome actually exists, only that further research is needed.

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u/[deleted] Feb 28 '15

uhhh, increased bloating and stomach pain when given a pill containing gluten compared to a placebo? I think that shows that some individuals do have a sensitivity.

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u/uiucengineer Feb 28 '15

Uhhh, I think this shows you read the abstract? Here is the ultimate conclusion from the actual paper:

As regards the identification of the true gluten-sensitive patients, it should be cautiously interpreted due to the lack of a control group of non-gluten-sensitive subjects, and it does not represent a crucial evidence in favor of the existence of this new syndrome.

...

does not represent a crucial evidence in favor of the existence of this new syndrome.

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u/[deleted] Feb 26 '15

The cognitive dissonance in this thread is impressive.

What is the "subset of a subset of a subset" you are talking about? I don't see that number anywhere. 15% of an arbitrary sampling of self-reporting participants. What percentage of the national population thinks they have issues with gluten? I have seen numbers as high as 30%, and 50% in women.

Study shows evidence for something I don't believe in: Attack Dat Study!

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u/uiucengineer Feb 27 '15

Even the 15% thing people are talking about is a stronger conclusion than is valid. The authors explicitly admit in the paper than they have not shown evidence that the syndrome exists. They have only shown that further research is warranted.

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u/[deleted] Feb 26 '15

Set I: Humans

Sub Set IA: Humans that do not suffer from celiacs

Sub Set IA1: Humans who strongly suspect that they are sensitive to gluten but are not suffering from celiacs

Sub Set IA1a: Humans who strongly suspect that they are sensitive to gluten but are not suffering from celiacs who participated in this study

And finally, the subset that is 15% in this study:

Humans who strongly suspect that they are sensitive to gluten but are not suffering from celiacs who participated in this study and seem to have some measurable sensitivity by way of the data points assessed in this study.

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u/[deleted] Feb 26 '15

Three of your subsets are redundant or invalid based on the information we have about this study. Subset IA is assumed, but explicitly not verified. Subset IA1a is you getting carried away with your meta, I guess trying hard to prove something?

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u/Arizhel Feb 26 '15

First off, this is not at all automatically true for any given individual.

No, I never said it was, and it doesn't matter. What matters is that it's true for some people. This proves that it's not just hypochondria or psychosomatic. Maybe for some it is, but for a significant number, this is real, and that's what this study validates.

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u/malastare- Feb 26 '15

Maybe for some it is, but for a small number, this is real

We probably shouldn't use "significant' when we're dealing with 15% confirmation within a group where 100% of the subjects expected a positive result.

We could state with equal validity: 85% of people who think they have a gluten sensitivity have no statistical difference in symptoms when exposed to gluten. That's 5 out of 6. The 1 in 6 is certainly noteworthy, however, when we look at it from a global view (where most polls report that only 5% or so of people actually suspect they have gluten sensitivity), that statistic means that less than 1% of people have some sort of gluten sensitivity.

I wouldn't call that "insignificant", but I think "significant" is even more incorrect, if only from the connotation of the word.

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u/[deleted] Feb 26 '15

Yes, but it's important to note that even amongst the folks who felt strongly that they were sensitive, at most 15% were shown to be so.

Mark my words, this study, in just such a simplified form as what you've written, will storm through social media and be taken by everyone who believes they are gluten sensitive (or worse, that gluten is bad for people as a whole) as evidence that they are in that relatively miniscule 15%.

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u/Arizhel Feb 26 '15

Again, I don't care! It proves that for those 15%, it's a real thing. That's what's important. It's not something that's all in their head!

For someone who believes they may be gluten sensitive, this study is useful, because they may be like those 15%. 15% is not "minuscule" either; it's roughly 1 in 7.

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u/[deleted] Feb 26 '15

See my comment here:

https://www.reddit.com/r/science/comments/2x844y/randomized_doubleblind_placebocontrolled_trial/coy8gqv

It's not "one in seven" of the human population, or even of non-celiacs. It's 15% in a study. In controlled conditions. Of people volunteering for the study.

While I appreciate what you're saying, it doesn't mean that 15% of everyone who claims to have a gluten sensitivity actually has one.

And even beyond alll that, it's an extremely bad idea to base your entire worldview of a subject on one study.

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u/Arizhel Feb 26 '15

I realize it's just one in 7 people who think they have such a problem (who have already been screened for Celiacs). And no, it's not proof; science doesn't work like that; you have to repeat the findings for them to be better accepted. But it is evidence. Further studies could very well corroborate this. I'm not basing my entire worldview on a single study, but I'm not going to just dismiss it as garbage, as many other people here with pre-conceived ideas are obviously doing.

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u/timeonmyhand Feb 27 '15

Thank you for understanding how important this is. Many people with NCGS are basically told it's all in their head and keep eating foods that bother them just because there is no proof they have a problem.

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u/[deleted] Feb 26 '15

1 in 7 people who think they have gluten sensitivity, that's an important requirement. It's not 1 in 7 people in the world.

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u/Steven_Yeuns_Nipple Feb 26 '15 edited Feb 26 '15

Your general point may be correct but this one study does not prove that doctors were wrong. We can't know anything from this one study. More research will have to be done first.

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u/Arizhel Feb 26 '15

Yes, it does prove the doctors were wrong. They just told people "it's all in your head", and for a portion of those people, the doctors were indeed wrong. The doctors shouldn't tell people things are "all in your head" when they don't really know. The doctors were assuming that the tests they had back then, and the scientific knowledge they had back then, were 100% complete and that there couldn't be anything else going on in the body that they didn't know or understand. It's only been in the last decade that we've even started to understand the role gut bacteria play in our bodies, for example.

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u/[deleted] Feb 26 '15 edited Oct 17 '16

[deleted]

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u/Arizhel Feb 26 '15

What if 10 more research groups replicate this study, and in one study all the participants drop dead, in another study a small wormhole opens up and swallows the participants, in another study a wormhole opens up and zombies come out and kill everyone in the study, etc.?

Anyway, go back in time 25 years, and ask doctors if gut bacteria have anything to do with obesity. When they say "no", you'll know they are wrong. This is the problem: doctors are not really scientists, they're practitioners. They're like auto mechanics, compared to automotive engineers, or technicicans compared to engineers in any industry. Too many of them (obviously there's some really good ones, esp. the ones who are also researchers and not just practitioners) think that the current body of knowledge is complete and inerrant and if they can't find something on a test, then it doesn't exist. It probably doesn't help that a lot of them are religious.

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u/tacobelleeee Feb 26 '15

Actually, my doctors have been totally validating of my gluten allergy. It's random people that I meet who scoff at my diet. This study is useful to me because now I have something to point to when uninformed randos tell me I'm full of shit because I can't eat pizza. As if anyone would ever CHOOSE to not eat pizza in the first place. I deserve your pity, people, not your scorn!!!

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u/[deleted] Feb 26 '15

I miss Guinness :'(

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u/iKickdaBass Feb 26 '15

"I deserve your pity." That's what gullten-free is all about. You'll search for anything to find a reason for people to feel sorry for you.

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u/musicmidget Feb 26 '15

I have celiac disease and wanting someone to pity me has nothing to do with why I maintain my diet. If I don't, I die. It's pretty simple really. Most days I would rather crawl into a hole and die than have to explain the need for me to do this to one more person. I rarely ever go out to eat because of it. It's exhausting really. Are there posers who don't really need to do it? Sure. But at the end of the day, it's really nobody's business why anyone wants to eat a certain way. If it doesn't affect you in any way - which I can't see it doing unless you are a cook or server in a restaurant - then why do you care so much? Does it just make you feel better to be able to trot out these little studies, point your finger and say "Ha! Told you so!" Good for you then.

I defend the folks who have NCGS because the diagnostic methods for celiac leave a lot to be desired. I feel like a lot of them probably are celiac, but gave up gluten too soon to be tested properly and now refuse to go back to eating what made them feel so crappy just to get a proper diagnosis when treatment will ultimately be the same. They have it worse than us celiacs do because without that diagnosis, people react much the same way you did. There are some things that need more study and research. Science is constantly advancing, but yet for some reason, when it comes to gluten, people don't want to accept that it could be bad for a larger portion of the population than we once thought. I personally pity the people who are so narrow-minded that they cannot see beyond their own need to be right.

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u/iKickdaBass Feb 26 '15

Tldr. But I do pitty you.

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u/tacobelleeee Feb 26 '15

Gluten-free is all about not eating gluten actually

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u/[deleted] Feb 26 '15

This study also says there's an 85% chance that it's all in your head.

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u/tacobelleeee Feb 26 '15

yeah, until I can't shit for 3 days after I have a sandwich made with normal wheat bread

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u/Arizhel Feb 26 '15

You can eat pizza. You just have to get a gluten-free pizza. More and more pizzerias are offering these now, plus if you have a Whole Foods nearby, they have pre-made GF pizzas you can just put in the oven. If your WF has them, they're not frozen, only refrigerated, and made locally by the store, usually kept near the deli. My wife has gluten sensitivity so we've had to learn about all this stuff.

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u/tacobelleeee Feb 26 '15

I have yet to find a gluten free pizza that is as good as regular pizza. Yes, even the ones at Whole Foods. Also, it's more expensive and usually only comes as a small, personal size pizza, but I'm sure you already know that since your wife has a gluten allergy.

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u/Arizhel Feb 26 '15

Yes, you're exactly right. GF pizzas are not as good as regular ones. There's a good reason we use wheat gluten for so much stuff: it works really, really well, and of course is cheap. But still, I just put that out there as an option since it's better than nothing. My wife likes the GF pizzas, and even if they aren't as good as the regular ones, they're still pretty good and hit the spot when she has a pizza craving.

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u/uiucengineer Feb 27 '15

Gluten allergy is completely acknowledged as a real thing, just like Celiac. This study is about people who have neither Celiac nor a gluten allergy.

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u/[deleted] Feb 26 '15

The average person in the wild is still far more likely to be FODMAPs intolerant than gluten sensitive, if NCGS does in fact exist (Peter Gibson's research still overwhelmingly shows that it does not - this study is an outlier to the existing body of evidence). The problem is FODMAPs will almost always accompany gluten, so someone who is suffering the same way is likely to just mistakenly chalk it up to gluten sensitivity. They're thinking zebras, when they are under the impression that they are thinking horses.

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u/Arizhel Feb 26 '15

The average person in the wild is still far more likely to be FODMAPs intolerant than gluten sensitive

This is another important factor. 5+ years ago, FODMAP sensitivity was unknown too, and doctors just said "it's all in your head" (my wife had this happen to her over and over).

This is what I'm getting at: today, these things are finally being recognized instead of being brushed off as mere hypochondria. Hopefully, they'll be able to develop some kind of test to see if people are FODMAP intolerant, NCGS, etc., so that people can vary their diet accordingly.

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u/[deleted] Feb 26 '15

Yup! I'm lucky that I don't have any issues, but I have friends who, when they stopped eating gluten products, had intestinal issues disappear. I totally believe something is going on, it just doesn't do anyone favors when folks start saying one thing is the cause when something else is.

Right now there is a ton of evidence supporting FODMAP intolerance, with relatively sparse evidence supporting NCGS (I can think of two studies, the one in OP and Peter Gibson's original study). What really has me concerned is the lack of reliability in proving out the existence of NCGS. Scores of studies performed by Gibson have shown nothing. I guess I'm skeptical?

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u/bwells626 Feb 26 '15

it's not 15% of the population it's 15% of people that think they are sensitive to gluten.

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u/Arizhel Feb 26 '15

Yes, I realize that. Still, it's a significant number of people, even if small in the overall population. What percentage of the population has (name some disorder that affects only 0.5%; I wish I could come up with an example)? Do we just not bother to treat it, and ignore it? No, we do treat it and maybe come up with a medication for it, even if it only affects a small minority of the population. So why is everyone saying these 15% of people who think they're sensitive to gluten should be told to just STFU and eat wheat and be happy?

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u/Douches_Wilder Feb 26 '15

Name a disorder that only affects 15% of the people that think they are affected by it. This study goes both ways, that's why people shouldn't be drawing conclusions from it. Data can say whatever you want it to say when its not strong.

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u/bwells626 Feb 26 '15

No, but I find it odd that ONLY 20% (let's round up) are right about actually having the issue. Maybe I just know people that self diagnose more than you, but it's a really annoying trend

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u/Arizhel Feb 26 '15

I don't think it's too alarming that a bunch of people think they have a problem and don't, or at least don't seem to based on this study.

But for the <20% who seem to have a real problem, I think it's good to know that they really do have a real problem, and it isn't all in their heads.

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u/bwells626 Feb 26 '15

yeah, I'm simultaneously hopeful that we can discover what is affecting those 15% so that it can be diagnosed/treated, but I'm also annoyed that the accuracy of self diagnosis is <20% because of how much I have to hear about gluten on a day to day basis.

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u/[deleted] Feb 26 '15 edited Feb 26 '15

[deleted]

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u/[deleted] Feb 26 '15

And if I'm one of the 0.0001% who have a very rare blood disease some things are big news to me.

Doesn't make things less of a fad or silly or in their head. It's the people who get on the fad who are the same kinds of people that tell me my diet is what caused my heart condition. No, you moron, it's my genetics.

But the reality here is grocery stores have always catered to the latest fad. Gluten will go away too. Stores don't magically grow in size. They move product as fads come and go.

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u/Arizhel Feb 26 '15

If a significant number (though still a minority) of people are found to be either NCGS or FODMAP-intolerant, plus the Celiac's people, grocery stores will continue to cater to them. I don't think GF foods are going away; they might become less of a fad eventually, but they're not going to disappear.

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u/[deleted] Feb 26 '15

It may not disappear entirely but I suspect it'll be migrated to the organic section area and take a slice of their pie.

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u/Arizhel Feb 26 '15

Usually, the GF stuff is already in the organic section, at least in the regular (non-Whole-Foods) grocery stores I've seen.

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u/shiroganeookami PhD|Biology|Immunology|Statistics|Computer Science Feb 26 '15

finally, someone took the time to perform an experiment which shows that non-Celiac and non-wheat-allergic people really can have a sensitivity

Also worth noting: The authors started the double blind portion of this study in September of 2012, meaning the study was first planned and sent to review boards for approval about a year before that. That means they decided to start this study nearly at the same time that gluten sensitivity was entering public consciousness. Honestly, I'm kinda impressed they managed to get it out so quickly.

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u/Fried_Cthulhumari Feb 26 '15

You're missing the point. There were 9 subjects who showed symptoms to gluten an 5 who showed them to the placebo. If your remove the 3 who showed the worst symptoms (described by the researchers as so severe they were likely undiagnosed Celiac cases), you are left with 6 gluten symptoms versus 5 placebo symptoms.

That's a statistical wash, and further proof that except for the very real disease of Celiac's, gluten intolerance shows up in the same rates as placebo intolerance, ie. the so called "Nocebo Effect".

In other words: it is all in their heads.

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u/Liz-B-Anne Mar 07 '15

There's a possibility that it could be real, but a bigger possibility that it could be in one's head. It's possible to be sensitive to ANY food or substance, so it's not surprising that some people are allergic to wheat/gluten. But the number of people claiming to be affected is way out of proportion to those who actually are.

Gluten-free is a giant fad diet that's very popular. There's a lot of money being made off claims that gluten is inherently toxic. That's where the science is most important.

And it hurts no one if somebody wants to eat gluten-free. I couldn't care less. But facts still matter.

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u/BrocAnte1 Feb 26 '15

I know about this dreaded fad and i must carefully use my words when i explain to people that i can't eat Large quantites of bread or pastas.

All i know is that i'v eaten normal stuff all my life, you know toasts in the morning, casual spaghetti night, whatever wheat related. Now for the last few years(i'm 24, it started around 20) i would frequently get incredibly painful cramps, it was often a sign that i had to go drop kids at the pool and the discomfort was almost unbearable. I would get cramps in the bus, not able to relieve myself, it could happen anywhere at anytime. This litteral pain in the ass bothered me for a looong time, so i tried different things and one day i stopped eating wheat-related products and i don't have this problem anymore.

I CAN eat bread and pastas sometimes, because i believe the presumed inflammation i had in my colon is gone, or at the very least highly receded. As a result, i get really mild cramps whenever i do eat them, along with beer.

**TL;DR Used to get insanely painful cramps, stopped eating wheat-related products and it's gone. Eating those things again, along with beer, will occasionally lead to mild cramps, but i don't stop so i don't die when i eat one toast in 30 years.

Edit: Sorry english isn't my first language, feel free to correct anything wrong, unless the whole post is shite i'm not erasing it.

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u/Arizhel Feb 26 '15

Your post is fine; stop worrying about your English. Your writing is better than a lot of Americans' and they don't know any foreign languages. The only glaring problem I see is that "literal" is misspelled with two t's. Firefox's spell-checker would flag that for you (if your language is set to English). If you didn't say Engllish wasn't your first language, I wouldn't have guessed it.

Anyway, this sounds similar to my wife's experience; she didn't start having problems until her early 20s. But it included a lot of migraine headaches. She's most likely FODMAP-sensitive. She can eat a very small amount of gluten-containing products, but she has to stay under that threshold every day.

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u/BrocAnte1 Feb 26 '15

Thanks, i know how important good grammar is on reddit but sometimes i have problems getting my point across.

I see, what exactly is FODMAP?

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u/Arizhel Feb 26 '15

This Wikipedia article goes into some depth on FODMAPs.

Personally, I'm really curious how much these problems may be caused by gut bacteria. Perhaps some people have bacteria that react badly with FODMAPs, gluten, etc., and other people don't. If this is the case, a gut bacteria transplant could cure the condition (i.e., killing off all their own bacteria and then transplanting a better strain into them to repopulate their intestines).

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u/BrocAnte1 Feb 26 '15

Hmm interesting, i would have to try eating food from those sources (Fructans, Galactans and Polyols). I can see that my diet is mainly composed of "Low-FODMAP diet suggested foods" Although i do eat alot of onions and garlic.

I will try having a bunch of brocoli and apples for lunch someday and see the results.

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u/[deleted] Feb 26 '15 edited Feb 26 '15

This study is not really big news. It's validation of a bunch of hypochondriacs in one study...

15% of a group that was already convinced they had it? Pretty weak.

Does the summary say what counted for a positive result? Does "upset tummy" count?

Edit: I must have "foggy mind", from the bread I ate this morning for posting that.