Is gluten sensitivity really caused by FODMAPs?

Recently, if everyone you know is anything like everyone we know, they’ve been sending you articles with headlines like:

And, if you’re anything like us, you’re pretty annoyed about it.

The study itself focuses on non-celiac gluten sensitivity (NCGS). Our own Peter Gibson and the other authors of a milestone 2011 study providing evidence for NCGS decided to check their results. They’d found no reason why gluten would cause digestive symptoms for non-celiac people, so they wondered if something went wrong in their first study—if there were confounding variables.

In their new study, they strove to control for those variables and found “no evidence of specific or dose-dependent effects of gluten in patients with NCGS placed diets low in FODMAPs.”

Unfortunately, no one is actually reading the study.

Most of the above “articles” don’t link directly to the study (which can be found here and, by the way, came out many months ago). Instead, they link to a write-up at Real Clear Science, suggesting that’s all they read. Real, clear, and scientific though that write-up may be, it is not enough to get the whole picture, especially if one reads it selectively.

Had writers taken time to learn something before jumping on the trending topic, the headlines may have been different. Or maybe not. After all, we clicked on them, didn’t we, and isn’t that the point?

The articles feature scant information, laughable errors, and a hearty, triumphant whiff of “I TOLD you nothing was wrong with you”—missing what the researchers take as a given: something is wrong. It just might not be gluten.

Now, one study does not overturn all the other research that’s been done on NCGS. Rather, it introduces doubt—and an opportunity to provide people with better treatments for the pain and discomfort they do indeed experience.

Since no one is bothering to read the study, here are some key points:

The 37 participants:

did not have celiac disease or other gastrointestinal diseases
did have symptoms of IBS fulfilling Rome III criteria
felt their symptoms improved with a gluten-free diet (though for some, the diet hadn’t helped 100%)
were not asked about non-intestinal symptoms (other than fatigue and sleep)

Like Jenny Craig, the researchers provided three meals a day, which were:

low-FODMAP (an acronym for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols—carbs that can cause digestive distress, and are found in wheat/rye/barley, among other foods)
dairy-free (you got this one)
low in “food chemicals”
keyed to caloric needs but otherwise identical
probably not that tasty

After establishing a baseline, the researchers mixed a little gluten, a lot of gluten, or a placebo into the meals. The trial was double-blind (so no one, including the researchers, knew who was getting what when) and cross-over (so participants spent some time eating each of the three kinds of meal).

The placebo was:

lactose-free whey protein
indistinguishable from the gluten in taste and texture

The results:

Participants all felt better on the baseline low-FODMAP diet (compared to their GF diet).
Some participants felt worse on the gluten-containing diets . . .
But a similar number also felt worse, to a similar degree, on the placebo-containing diet, pointing to a “nocebo” (negative placebo) effect.

The researchers’ conclusions:

“NCGS, as currently defined, might not be a discrete entity.”
FODMAPs may be the primary issue, or gluten might cause symptoms only in the presence of FODMAPs.
The gluten in this study might have been different from the gluten in the first study and thus had different effects.
NCGS may cause mostly neurological, mood-related, and other non-digestive symptoms.
More research is needed!

Of course, the click-me-click-me articles don’t get far beyond bullet point #1. As such, they aren’t worth getting worked up over, though that hasn’t stopped me (The Experiment’s token celiac) from practically combusting every time a friend broaches the topic. People are finally paying attention, and in all the wrong ways. It drives me bonkers.

The takeaway that few are taking away

Something other than gluten might be causing symptoms for those who consider themselves gluten-sensitive. Many researchers, doctors, and dietitians now place the blame on FODMAPs.

As editor of Sue Shepherd and Peter Gibson’s The Complete Low-FODMAP Diet and Sue Shepherd’s The Low-FODMAP Diet Cookbook (on shelves very soon!), I wish that articles would focus more on promoting this revolutionary treatment—the only evidence-supported diet for IBS—and less on dissing another.

The low-FODMAP diet doesn’t work for everyone (its success rate for IBS is about 75%), just as a gluten-free diet doesn’t work for everyone. But gluten-free may work for fewer people than we previously suspected. So if you’ve cut gluten but still have symptoms, you might want to give low-FODMAP a try.

Our guess? There’s room for both diets. And there’s plenty of room for more research.

An expanded version of this post originally appeared on Molly’s personal blog.