Author Topic: Non-Celiac Gluten Sensitivity May Not Exist  (Read 403 times)

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Non-Celiac Gluten Sensitivity May Not Exist
« on: May 16, 2014, 01:39:16 PM »
http://www.realclearscience.com/blog/2014/05/gluten_sensitivity_may_not_exist.html

Non-Celiac Gluten Sensitivity May Not Exist

Posted by Ross Pomeroy May 14, 2014

In 2011, Peter Gibson, a professor of gastroenterology at Monash University and director of the GI Unit at The Alfred Hospital in Melbourne, Australia, published a study that found gluten, a protein found in grains like wheat, rye, and barley, to cause gastrointestinal distress in patients without celiac disease, an autoimmune disorder unequivocally triggered by gluten. Double-blinded, randomized, and placebo-controlled, the experiment was one of the strongest pieces of evidence to date that non-celiac gluten sensitivity (NCGS), more commonly known as gluten intolerance, is a genuine condition.

By extension, the study also lent credibility to the meteoric rise of the gluten-free diet. Surveys now show that 30% of Americans would like to eat less gluten, and sales of gluten-free products are estimated to hit $15 billion by 2016 -- that's a 50% jump over 2013's numbers!

But like any meticulous scientist, Gibson wasn't satisfied with his first study. His research turned up no clues to what actually might be causing subjects' adverse reactions to gluten. Moreover, there were many more variables to control! What if some hidden confounder was mucking up the results? He resolved to repeat the trial with a level of rigor lacking in most nutritional research. Subjects would be provided with every single meal for the duration of the trial. Any and all potential dietary triggers for gastrointestinal symptoms would be removed, including lactose (from milk products), certain preservatives like benzoates, propionate, sulfites, and nitrites, and fermentable, poorly absorbed short-chain carbohydrates, also known as FODMAPs. And last, but not least, nine days worth of urine and fecal matter would be collected. With this new study, Gibson wasn't messing around.

37 subjects took part, all with self-reported gluten sensitivity who were confirmed to not have celiac's disease. They were first fed a diet low in FODMAPs for two weeks, then were given one of three diets for a week with either 16 grams per day of added gluten (high-gluten), 2 grams of gluten and 14 grams of whey protein isolate (low-gluten), or 16 grams of whey protein isolate (placebo). Each subject shuffled through every single diet so that they could serve as their own controls, and none ever knew what specific diet he or she was eating. After the main experiment, a second was conducted to ensure that the whey protein placebo was suitable. In this one, 22 of the original subjects shuffled through three different diets -- 16 grams of added gluten, 16 grams of added whey protein isolate, or the baseline diet -- for three days each.

Analyzing the data, Gibson found that each treatment diet, whether it included gluten or not, prompted subjects to report a worsening of gastrointestinal symptoms to similar degrees. Reported pain, bloating, nausea, and gas all increased over the baseline low-FODMAP diet. Even in the second experiment, when the placebo diet was identical to the baseline diet, subjects reported a worsening of symptoms! The data clearly indicated that a nocebo effect, the same reaction that prompts some people to get sick from wind turbines and wireless internet, was at work here. Patients reported gastrointestinal distress without any apparent physical cause. Gluten wasn't the culprit; the cause was likely psychological. Participants expected the diets to make them sick, and so they did. The finding led Gibson to the opposite conclusion of his 2011 research:

“In contrast to our first study… we could find absolutely no specific response to gluten."

Instead, as RCS reported last week, FODMAPS are a far more likely cause of the gastrointestinal problems attributed to gluten intolerance. Jessica Biesiekierski, a gastroenterologist formerly at Monash University and now based out of the Translational Research Center for Gastrointestinal Disorders at the University of Leuven in Belgium,* and lead author of the study alongside Gibson, noted that when participants consumed the baseline low-FODMAP diet, almost all reported that their symptoms improved!

"Reduction of FODMAPs in their diets uniformly reduced gastrointestinal symptoms and fatigue in the run-in period, after which they were minimally symptomatic."

Coincidentally, some of the largest dietary sources of FODMAPs -- specifically bread products -- are removed when adopting a gluten-free diet, which could explain why the millions of people worldwide who swear by gluten-free diets feel better after going gluten-free.

Indeed, the rise in gluten sensitivity seems predominantly driven by consumers and commercial interests, not quality scientific research.

"On current evidence the existence of the entity of NCGS remains unsubstantiated," Biesiekierski noted in a review published in December to the journal Current Allergy and Asthma Reports.

Consider this: no underlying cause for gluten sensitivity has yet been discovered. Moreover, there are a host of triggers for gastrointestinal distress, many of which were not controlled for in previous studies. Generally, gluten-sensitivity is assumed to be the culprit when celiac's is ruled out. But that is a "trap," Biesiekierski says, one which could potentially lead to confirmation bias, thus blinding researchers, doctors, and patients to other possibilities.

Biesiekierski recognizes that gluten may very well be the stomach irritant we've been looking for. "There is definitely something going on," she told RCS, "but true NCGS may only affect a very small number of people and may affect more extraintestinal symptoms than first thought. This will only be confirmed with an understanding of its mechanism."

Currently, Biesiekierski is focused on maintaining an open mind and refining her experimental methods to determine whether or not gluten sensitivity truly exists.

"We need to make sure that this research is as well controlled as possible and is reproducible," Biesiekierski told RCS, subsequently adding the quintessential adage of proper science.

"Much, much more research is needed."

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Online mountaineer

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Re: Non-Celiac Gluten Sensitivity May Not Exist
« Reply #1 on: May 16, 2014, 02:08:44 PM »
Quote
The data clearly indicated that a nocebo effect, the same reaction that prompts some people to get sick from wind turbines and wireless internet, was at work here. Patients reported gastrointestinal distress without any apparent physical cause. Gluten wasn't the culprit; the cause was likely psychological. Participants expected the diets to make them sick, and so they did.  ... Indeed, the rise in gluten sensitivity seems predominantly driven by consumers and commercial interests, not quality scientific research.
I've long suspect that gluten intolerance was just another ailment-of-the-month, whipped by the gullibility of a non-discerning public who are quick to self-diagnose (based on the latest thing seen on Oprah, Dr. Oz or The View, apparently).
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Offline Oceander

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Re: Non-Celiac Gluten Sensitivity May Not Exist
« Reply #2 on: May 16, 2014, 02:30:27 PM »
I've long suspect that gluten intolerance was just another ailment-of-the-month, whipped by the gullibility of a non-discerning public who are quick to self-diagnose (based on the latest thing seen on Oprah, Dr. Oz or The View, apparently).


Yup.

Offline katzenjammer

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Re: Non-Celiac Gluten Sensitivity May Not Exist
« Reply #3 on: May 16, 2014, 03:20:22 PM »
I've wondered about this.  Both of my sisters bought into this and jump through hoops to avoid gluten in their families' diets.  I have asked them, "what about all of the gluten that you had been eating for 6 decades or more??  never bothered you then??" to which they reply, "well, I'm sure that it caused all sorts of problems that we just didn't know about!"   Can't argue with that!!  lol   :shrug:


Offline Chieftain

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Re: Non-Celiac Gluten Sensitivity May Not Exist
« Reply #4 on: May 16, 2014, 04:15:47 PM »
I've wondered about this.  Both of my sisters bought into this and jump through hoops to avoid gluten in their families' diets.  I have asked them, "what about all of the gluten that you had been eating for 6 decades or more??  never bothered you then??" to which they reply, "well, I'm sure that it caused all sorts of problems that we just didn't know about!"   Can't argue with that!!  lol   :shrug:

yah....it's like trying to listen to someone tell you the exact benefits of chiropractic treatments, or why they believe that childhood vaccines are dangerous while feeding their kids on raw milk......

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Offline Oceander

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Re: Non-Celiac Gluten Sensitivity May Not Exist
« Reply #5 on: May 16, 2014, 05:30:09 PM »
I've wondered about this.  Both of my sisters bought into this and jump through hoops to avoid gluten in their families' diets.  I have asked them, "what about all of the gluten that you had been eating for 6 decades or more??  never bothered you then??" to which they reply, "well, I'm sure that it caused all sorts of problems that we just didn't know about!"   Can't argue with that!!  lol   :shrug:



My sister is like that.  There's no sense even asking about it because it's like banging your head against a brick wall - and brick walls are too precious to waste that way!

Offline katzenjammer

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Re: Non-Celiac Gluten Sensitivity May Not Exist
« Reply #6 on: May 17, 2014, 11:49:05 AM »
My sister is like that.  There's no sense even asking about it because it's like banging your head against a brick wall - and brick walls are too precious to waste that way!

Yes, I am amazed at how so many things have popped onto their "must not use" lists over the years, only to be replaced in a few years....   :shrug:

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Re: Non-Celiac Gluten Sensitivity May Not Exist
« Reply #7 on: May 17, 2014, 03:07:01 PM »
My niece has actual celiac disease, confirmed by the Mayo Clinic. If just a hint of flour dust wafts through the air and lands on her food, she gets sick and suffers a great deal of pain. That's why I'm tired of the self-diagnosed who jump on the latest bandwagon, in this case the "cut out gluten and all your imaginary ailments will be cured" bandwagon.
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Re: Non-Celiac Gluten Sensitivity May Not Exist
« Reply #8 on: May 17, 2014, 04:05:31 PM »
I suffered serious intestinal distress for 10 years without knowing that the cause was wheat. By chance I went on the Atkins diet and discovered my symptoms disappeared. After going wheat-free for three years I was then able to have small amounts of wheat without reaction. That was 20 years ago and I'm good to this day as long as I don't have too much bread at one sitting.

The curious thing is, however, when I was growing up my family ate pasta and bread every day and I don't recall having symptoms until I was about 30! Think that shows that there is still much we don't understand about wheat intolerance.

Anyway I agree with others here that unless you're having cramps, diarrhea and bloating, going gluten-free is pointless.
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