Does Gluten Have Any Effect on Non-Celiacs?

WheatThe headlines are everywhere: gluten sensitivity doesn’t actually exist, and anyone who thinks they have it is a liar, delusional, dumb, or all three. The message isn’t a new one, but the stories do point to a new study from a group of researchers who previously found that removing wheat from the diet improved symptoms in people with IBS. In the new paper, the researchers tested whether isolated gluten – rather than wheat – exacerbated IBS symptoms. It did not. The IBS patients in the latest study showed no reaction to isolated gluten, and the only dietary variable that increased their symptoms was wheat. This could suggest that at least for some people (with IBS), gluten sensitivity may actually be wheat sensitivity triggered by the fermentable FODMAP fibers found in the grain.

Folks are so eager to say “told ya so!” that they gloss over an important fact: going gluten-free still worked. Sure, I guess some IBS patients can start doing lines of isolated gluten powder or whatever, but if the FODMAP mechanism holds, they’re still not eating wheat. They’re still gluten-free, or wheat-free, or whatever you want to call it – and they’re still experiencing relief from debilitating symptoms.

The “why” is certainly important. It’s interesting. It provides jobs for researchers and fodder for online arguments. It can lead to effective treatments and pharmaceutical interventions. But it doesn’t affect the people, here today, dealing with health issues who cannot wait around for a consensus in the literature. They need results, and going gluten-free tends to work more often than not. And going gluten-free does not hurt as long as you don’t just replace gluten grains with gluten-free junk food.

But today’s post isn’t really about that.

People typically analyze gluten sensitivity through the prism of gastrointestinal distress. It’s often the first symptom we notice. It’s certainly the most obvious. If you don’t have celiac but eat some gluten and your stomach feels bubbly and the toilet becomes irresistible, you have non-celiac gluten sensitivity. If you can eat pizza without diarrhea, bloating, constipation, and/or inordinate amounts of gas, you probably don’t.

That’s how I know I’ve eaten gluten – my gut tells me. But for many people, there are extraintestinal, peripheral symptoms. And these aren’t just mass delusions. Legitimate research is discovering and beginning to unpack the connections between gluten, wheat, and a host of other disorders, even in the absence of celiac disease.

Those symptoms and disorders may still be mediated by the gut, but they’re not always felt in the gut. Kind of like how a tight muscle can affect other tissues along seemingly unrelated sections of the kinetic chain (ankle dysfunction can cause knee pain, for example).

The following are not ironclad, proven causal relationships. They describe correlations with plausible mechanisms, hypotheses still to be proven. I’m omitting any relationships purely based on anecdote, not to discount them, but to focus on the strongest candidates for conditions caused or exacerbated by gluten in non-celiacs.


The mysterious, painful condition known as fibromyalgia has long been connected with celiac disease and general gut disturbances (IBS is quite common in fibromyalgia patients, for example, and IBS patients with fibromyalgia often have celiac). But only recently has non-celiac gluten sensitivity also been linked to fibromyalgia. Researchers selected 20 patients with fibromyalgia who experienced remission upon switching to a gluten-free diet, with remission including one or more of the following improvements: reduction in pain, return to work, return to normal life, or the discontinuation of painkillers. Tests confirmed they did not have celiac, leading the authors to suggest that “non-celiac gluten sensitivity may be an underlying case of FM syndrome.”


Gluten-free (often casein-free) diets are popular with many parents of kids on the autism spectrum, but most physicians have taken a skeptical stance on the whole premise. That’s to be expected. However, parents who report the strictest implementation of a gluten-free diet in their kids with autism report the largest improvements in symptoms. Oh, that’s just a large, admittedly well-documented and externally-verified compendium of anecdotes, you say? Recent research has shown that a subset of autistic kids show enhanced reactivity to gluten distinct from the response characteristic of celiac disease. You can certainly say that going gluten-free probably won’t help every kid with autism, but it looks like a portion of them are going to benefit from its removal.

(If there are any Spanish speakers in the house, check out this free full-text paper for a further look at the evidence. I’d be curious to hear what it has to say.)

Type 1 Diabetes

In pregnant mice who were diabetic but not celiac, a maternal gluten-free diet maintained during breastfeeding up until weaning reduced both inflammation and type 1 diabetes in the offspring. Pancreatic regulatory T-cells (which suppress inflammation) and tight junction activity were both up-regulated in the GF offspring. This echoes other rodent studies stretching back to the 1990s. Okay, but those are mice. They’re cute and mammalian and all, but what about human research? Most recently, a six year old with type 1 diabetes experienced remission upon adopting a gluten-free diet. Twenty months later, he was still off insulin therapy.


For nearly 50 years, a large body of research has tentatively established links between schizophrenia and wheat consumption. A 1966 study found that as wheat and rye consumption increased following World War 2, hospital admissions for schizophrenia also increased. Later that decade, the otherwise rare celiac disease was discovered to be oddly common among patients with schizophrenia, while early interventions saw some success at treating relapsed schizophrenia with grain-free diets. Abnormal sensitivity to gluten isn’t universal among patients, but there appears to be something there. And research continues to this day, with a recent meta-analysis finding that certain markers of gluten-sensitivity are elevated in schizophrenics compared to controls (and differently than in celiacs). Maternal gluten sensitivity is even related to the offspring’s chance of developing schizophrenia.


A recent case study found that a gluten-free diet led to remission of depression symptoms in a patient with non-celiac gluten sensitivity. A placebo-controlled trial from this year found that while isolated gluten added to a gluten-free diet did not cause GI distress (just like the study described in the introduction), it did increase symptoms of depression in a group of patients with “self-reported” non-celiac gluten sensitivity.


Not as well-known as some of the other conditions mentioned, ataxia is a neurological disorder characterized by an inability to control gait, balance, and hand-eye coordination. It’s incredibly serious, and multiple reports link it to gluten sensitivity. They even call a subset of it gluten ataxia, which is not accompanied by celiac-related enteropathy. A recent trial in patients with ataxia found that a gluten-free diet significantly improved symptoms, irrespective of GI symptoms.

Clearly, looking at the gut for evidence of non-celiac gluten sensitivity is not enough. And yes, it may very well turn out that it’s something else in the wheat causing the issues in these conditions, too, but does that change the effective therapy – a gluten-free/wheat-free diet?

No. It still works.

If any of these conditions affect you or someone close to you, a gluten-free diet may be worth trying. It’s free, after all.

Thanks for reading, all. For those of you with personal experience with any of these conditions, has going Primal – and gluten-free – helped at all? I’m really curious to hear.

Prefer listening to reading? Get an audio recording of this blog post, and subscribe to the Primal Blueprint Podcast on iTunes for instant access to all past, present and future episodes here.

TAGS:  gluten

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

If you'd like to add an avatar to all of your comments click here!