Non-Celiac Gluten Sensitivity Still Probably Doesn't Exist
Three years ago, I reported on a relatively unheralded nutrition study. Although the research had been missed or passed over by the mainstream press, I had a feeling this study would attract widespread attention. Unlike most other nutrition studies, this one was exceedingly rigorous. Moreover, its findings ran counter to prevailing wisdom and market trends. In preparation for publishing my report, I dotted every "i" and crossed every "t", yet despite hours of fine-tuning and fact-checking, I wasn't prepared for the firestorm the study provoked.
Its findings captured with the headline "Non-Celiac Gluten Sensitivity May Not Exist," the double-blind, randomized, placebo-controlled study demonstrated that patients diagnosed with non-celiac gluten sensitivity, an adverse reaction to gluten in the absence of celiac disease, showed no specific response to gluten, a common protein in bread products. By extension, the ballooning gluten-free fad was likely BS.
Millions read my piece here at RCS, and pretty much every other media outlet picked up the story. To my surprise, I was even offered book deals to capitalize on the sudden attention (I declined).
When the publicity died down, what remained to be seen was whether or not evidence would have any effect on public sentiment. Although the proportion of Americans considering gluten-free to be a fad grew from 31% in 2013 to 47% in 2015, sales of gluten-free products grew by any even larger margin. Between 2013 and 2015 sales of gluten-free products rose 136% to $11.6 billion!
Clearly, the gluten-free craze has continued relatively unchanged, but what about the science? Three years ago, the existence of non-celiac gluten sensitivity was "unsubstantiated." That conclusion persists today.
In a review published December of last year to the journal Current Gastroenterology Reports, a trio of scientists from the Center for the Prevention and Diagnosis of Celiac Disease in Milan, Italy examined the most up-to-date evidence on non-celiac gluten sensitivity.
"Direct implication of gluten in the onset of symptoms is often unproved..." they wrote. "To date, no specific biomarkers or histological abnormalities confirm diagnosis, and only the self-reported response to gluten-free diet as well as a positive double blind placebo-gluten challenge characterizes these non-celiac, non-wheat allergic patients."
More research had been conducted, the reviewers noted, but the studies overwhelmingly showed that the vast majority of subjects with suspected gluten intolerance didn't actually respond negatively to gluten. Moreover, other dietary factors, including FODMAPs and other natural cereal proteins, couldn't be ruled out as causing subjects' symptoms.
"In this chaotic scenario without strong evidence about gluten involvement and utility of gluten-free diet in patients with non-celiac gluten sensitivity and in the absence of simpler diagnostic tools, it is recommended that subjects avoid self-diagnosis and self-treatment," the reviewers concluded.
In layman's terms, the scientists suggested that going "gluten-free" because you think you might be "sensitive" is not a good idea.
Through better, more in-depth research, it's still possible that scientists will definitively pinpoint gluten as causing the bloating, abdominal pain, diarrhea, tiredness, and headache that sufferers of "gluten intolerance" endure. But today, we're left with nearly the same conclusion as three years ago: non-celiac gluten sensitivity probably doesn't exist.