Gluten, a substance found in wheat and many other food products, has been a health industry “bad guy” for the past several years. Scientists and nutritionists have claimed that non-celiac gluten sensitivity (NCGS) can cause everything from gut problems to brain problems to skin problems. And the health industry has responded by promoting gluten-free products, services, and diets.
This year, however, a study became infamous for potentially disproving the very idea of non-celiac gluten sensitivity.
Is Non-Celiac Gluten Sensitivity Even Real?
In 2011, Peter Gibson, from Monash University in Melbourne, published a study that suggested gluten may contribute to intestinal problems in people without celiac disease, which is an intestinal condition. Later, this study was sort of confirmed by another study at the University of Palermo. I say “sort of,” because the study only showed a link between wheat and digestive-tract issues.
Gibson, however, wanted to put his first test to the test, and he was very thorough the second time around. He used an elimination diet that removed any potential triggers that could cause intestinal issues. Primarily, he focused on the removal of FODMAPs, which are certain types of carbohydrates that tend to cause more pressure in the intestines than other foods.
Typical dietary sources of FODMAPs can include certain types of fructose in fruit, coconut products, fibrous vegetables, sugar alcohols, and dairy products.
This test’s subjects didn’t previously have celiac disease, but did claim to suffer from gluten sensitivity. For the first two weeks, all the subjects were fed the elimination diets that were low in FODMAPs. During this time, everyone reported feeling better. After the low-FODMAPs diet, they were shuffled through three separate elimination diets: high-gluten diets, low-gluten diets, and placebos (the low-FODMAPs diet).
Every participant ran through each type of diet at different times, without knowing which type of diet they were on. What Gibson found, however, was surprising.
We could find absolutely no specific response to gluten
Even when the subjects were on the placebo diet, they said they felt worse. And Gibson found that throughout the test, no one responded the same way twice to low-gluten diets.
In contrast to his first test, Gibson concluded that “we could find absolutely no specific response to gluten” and that “gluten may not be a specific trigger of functional gut symptoms once dietary FODMAPs are reduced.”
Gluten-Sensitivity May Actually be FODMAP-Sensitivity
Gluten itself may not be responsible for intestinal issues. Instead, FODMAPs and other substances in wheat may be the culprit. The University of Palermo study, as mentioned above, only confirmed wheat sensitivity, not gluten sensitivity.
Follow-up studies by Jessica Biesiekierski, a former colleague of Gibson’s, reported that reducing FODMAPs, such as bread products, reduced intestinal problems. Bread, a major source of gluten, also happens to be a major source of FODMAPs.
Gluten sensitivity remains unsubstantiated
Biesiekierski also concluded that “the existence of the entity of NCGS remains unsubstantiated.”
Previous evidence suggested that gluten was the bad guy, but what about now? Should you throw away all your FODMAPs and pick up the gluten again?
Not necessarily. It’s important to remember that this study was focused, first of all, on gluten and its relationship to intestinal problems, not skin issues. There is some evidence to show gluten can aggravate skin problems for some people, as documented in my earlier post about gluten.
Though the evidence seems to point away from gluten as far as intestinal problems go, it’s important not to jump to conclusions. Food sensitivity studies are quite difficult to do. Also, the psychological placebo effect also complicates things, since they rely on patient’s personal experiences. As Biesiekierski said, “Much, much more research is needed.”
Hi Seppo,
i have a question about this post: How many people were used in the study you quoted here? i read about a study of around 35 people. Is that the one?
Meanwhile, it seems there are many other studies that suggest that non-celiac gluten sensitivity is real, and there are doctors who can treat their patients with diagnose of gluten sensitivity. i think there needs to be extensive discussion with those practitioners who know a lot of other studies before drawing a conclusion. Here’s a concentration of leads to the practitioners saying the opposite: https://thedr.com/
Thanks!
Don’t remember now, but 35 sounds more or less correct. It wasn’t a huge study, but this is quite normal size for studies of this type. It’s expensive and difficult to run dietary studies on large groups of people.
As far as I understand there aren’t that many studies. And the ones that show gluten sensitivity is real are not the most reliable. It’s possible that what those studies show is not a problem with gluten but something else in wheat. Please see the post at Science-Based Medicine blog linked to at the references section for a comprehensive overview of the studies.
As far as I understand, there’s no good evidence to show either way. Later studies point to non-celiac gluten sensitivity not being real, but these are by no means conclusive studies.
I’d also like to point out that many people will benefit from not eating wheat. But that may not be because of gluten but because of other substances in wheat, like FODMAPs.
The link you gave doesn’t load for me, so I can’t comment on it.
Hi Seppo, thanks for your reply!
I’ve heard a lot of discussions about gluten recently. I’m not an expert, but the experts have quoted sources. It seems there are a lot of studies, plus actual medical practice. Yes, it’s true that there’s something else (Gliadin?) that might be more destructive in gluten containing grains such as wheat.
What I’ve learned recently is that gluten and/or the other substance causes “leaky gut”, hence inflamation. So that inflamation would lead to symptms such as acne.
Perhaps you can check this on GreenMedinfo which presents and interprets finding published on PubMed, and see if there are leads to relevant info: https://www.greenmedinfo.com/disease/gluten-sensitivity
Here’s a page about leaky gut: https://www.greenmedinfo.com/blog/4-steps-heal-leaky-gut-and-autoimmune-disease
I remember the other resource i quoted earlier has a talk that mentions (and criticizes) the 35 people (large scale 🙂 ) study. Anyway, again i’m not an expert. I’m just providing some leads for the discussion.
Also, they talk about “cross-reactivity” – certain foods, though not containing gluten, would trigger responses similar to dealing with gluten-containing foods.
I appreciate all your great work!
You are asking for more than I can deliver here. One could write a book to answer the points you raised. But let me give you a few pointers to think about.
Yes, I’m sure there are hundreds of studies that show gluten is problematic. But 95 of those are test tube studies where researchers look at how cells react to gluten. Such studies are fine for preliminary research, but we can’t use them to say gluten is dangerous.
You have to know what you can and cannot conclude from a study. And I understand that for someone with little understanding on medical research this is next to impossible. Sadly the alt-med world abuses this constantly. They parade test tube and animal studies as if they were valid evidence of health effects in humans.
Another thing you have to consider is that reported adverse reactions to gluten may be triggered by something else in grains. This of course causes additional uncertainty. What I liked about this study was that it did a fairly good job at controlling for that. People were exposed 4 times to either gluten or whey (as placebo). One would expect that people with true gluten sensitivity would show adverse reactions when exposed to gluten but little to no reaction when exposed to whey. But the results showed that the vast majority of people didn’t consistently react to gluten. Sometimes they reacted to gluten, sometimes to whey and sometimes gluten had no effect. This is almost a classic nocebo effect.
I’m sure people have criticized the study for being too small and for other reasons. You can always find faults in studies. Especially if the study results go against their dogma, such as ‘gluten is bad’. 35 participants is quite a small study, but it’s fairly normal for such studies. Just keep in mind that just because a study isn’t perfect it doesn’t mean the results would be wrong.
Anyway, knowing what you can and cannot conclude from studies is quite difficult. That’s why I suggested you read the post at Science-Based Medicine blog. It’s written by doctors and researchers who understand this stuff well.
Sorry for posting twice! i was meaning to just add one sentence: “Also, they talk about “cross-reactivity” – certain foods, though not containing gluten, would trigger responses similar to dealing with gluten-containing foods.”