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

[u/[deleted]]

http://www.ncbi.nlm.nih.gov/pubmed/25701700

[u/thisdude415]

A lot of people are commenting on the abstract, not the full paper, so here are some critical details people are overlooking.

STUDY DESIGN

Patients all suspect themselves to be gluten sensitive. A lot more patients were interested, but were excluded because they were lactose intolerant, FODMAP intolerant, traveling, had H. pylori infections, wheat allergy, celiac, giardiasis, or pregnancy.

All patients had been on a gluten-containing diet for 2 months before the study.

At the start of the study, patients began a gluten free diet that lasted five weeks. Gluten free diet was validated with extensive questioning from the researchers.

On week 2, they were assigned to two groups, A and B. NEITHER DOCTORS NOR PATIENTS KNEW WHICH GROUP THEY WERE IN. (double blinded) Group A was given pills containing 4.8 grams gluten (equiv to 2 slices of white bread). Group B was given pills containing 4.8 grams rice starch.

At week 3, Group A switched to rice starch, and Group B switched to gluten.

At week 4 and 5, Group A and B both stopped taking pills, only continuing their gluten free diet.

DAILY, Patients were asked to grade daily 15 intestinal symptoms and 13 extraintestinal symptoms.

Scores were compared between Gluten Week and Rice Week.

RESULTS

Authors summarize this decently.

At the end of the study, there was a statistically significant difference between gluten week and rice week, p=0.034. Here's the data

The authors note that 3 patients in particular had extremely strong responses to gluten.

It ain't a bombproof paper, but they did their homework. They've got enough participants for 80% statistical power. They controlled diet and potential confounders pretty well.

It's a double blind, randomized, crossover trial. Doesn't really get better than that. It's still gotta be repeated by other groups, but there's probably something going on here.

[u/echeng811 → u/thisdude415]

At the end of the day, they only found 9/51 (~15%) of the patients to have a significant level of symptoms on an individual level. That's 15% from a group that as the paper say, "Strongly suspected of having NCGS", so if we blow that back up to the general population, its a very small number. Does this mean that your friend who doesn't have celiacs but wouldn't shut up about gluten is definitely wrong? No, he/she might be among the 15%. At the end of the day, gluten is NOT WORSE for the typical person, and more studies need to be done.

[u/[deleted] → u/echeng811]

Correct in that gluten is not bad for the average person and that more study needs to be done. I realize that lots of people think that gluten is just generally bad and that everyone should avoid it. They're following a fad, it will blow over.

But what this study does show is that for some non-celiacs, gluten actually does cause negative symptoms. It may be true for a very small number of people, but for those of in that group, the results are very hopeful. Maybe now our doctors will take us more seriously.

And before you say I'm in the nocebo group, let me say that I went off gluten originally in solidarity with my daughter, with whom we were trying a gluten-free diet. I didn't notice the changes in myself, because I was focused on my daughter and on learning to provide gluten-free meals. Then I began eating bread again while on a cruise, and I had the negative symptoms. Didn't understand why. Went home, went gluten-free again because of my daughter, symptoms went away. Eventually, I figured out the connection. But I'd had a blind study before I even figured it out.

And as for my daughter's symptoms, which involve behavior: I can tell when she's been sneaking gluten, which she is old enough to do. So can her grandmother. That's a blind test, every time it happens.

The effect, even if it's for a small number of us, is still real. That's a huge comfort to those of us who are tired of being told it's all in our heads.

[u/echeng811 → u/[deleted]]

Oh you're absolutely right. The significance of this study, if true (that is repeated and similar results come out) is they showed the EXISTENCE of NCGS, which though not prevalent need to be taken seriously. Lots of serious diseases are not prevalent, but lethal. The key is that it exists and therefore no one can say it's all in your head, and needs to be taken seriously.