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By David Warmflash

David Warmflash“Errors are volitional and are the portals of discovery,” wrote James Joyce. It may sound trite a century later, but the lesson is all the more important in an age when science and technology control virtually every aspect of human civilization.

Science has been wrong on countless occasions, yet it keeps advancing because it recognizes its mistakes and reevaluates. Typically, corrections come from new researchers who were not involved in the original study. But sometimes it comes from the scientists who made the error. That’s what happened on the gluten issue, and it’s a wonderful example of science at its best.

Gluten-free products are everywhere. That’s a good thing, because many people suffer from celiac sprue. Also known as gluten-sensitive enteropathy, it’s a chronic condition caused by an inflammatory reaction to gliadin, one of the proteins making up gluten and found in wheat, barley, and rye. Gliadin gives bread its elasticity, but it wreaks havoc if ingested by someone whose immune system is genetically prone to send T-lymphocytes to attack it. In such cases, the intestinal mucosa is damaged, leading to malabsorption of nutrients. Failure to absorb food leads to malnutrition, weakness, and weight loss, plus flatulence, borborygmus, and diarrhea due to undigested food continuing through the gastrointestinal (GI) tract. This can lead to GI cancers, miscarriages, and other complications, but the entire maldigestion cascade can be avoided when a known celiac individual avoids ingesting gluten in the first place.

The prevalence of celiac sprue is roughly 1% in the United States. It’s underdiagnosed; so many of the 1% should be on a gluten-free diet but are not. The gluten-free food that’s available everywhere is not getting to the right people.

Yet, according to a series of new studies, it’s doing an excellent job at getting to the wrong people, and you can find them almost everywhere and in every stage of life. My preschooler talks about the “gluten-free kids” at school: three of them in a class of sixteen, which is in line with the 18% of adults who now buy gluten-free food.

GlutenMonsterThe reason for the discrepancy in the numbers is a postulated condition called “non-celiac gluten sensitivity” (NCGS), characterized by irritable bowel syndrome (IBS)-like symptoms. Evidence first came in a small, but well-reasoned, placebo-controlled study in early 2011. Over the next two years, it was debated, because there are other things in grainy foods that can cause gas and malabsorption. Notably, grains contain fermentable, oligo-, di-, and mono-saccharides and polyols (FODMAPs). When not digested enough early in the GI tract due to insufficient amounts of the needed enzymes, they become food for bacteria, which release hydrogen, carbon dioxide, and other gases. FODMAPs exist not only in glutenous grains but also in notoriously gassy foods such as broccoli and beans.

Based on subsequent experiments, the same authors published a new study last year showing that IBS-like effects in nonceliac patients actually cannot be attributed to gluten but more likely to FODMAPs. This was followed up this year by another study showing that a low-FODMAP diet eliminates IBS symptoms, regardless of the how much gluten is in the food. The story developed further in April with another study, this one casting further doubt on the existence of NCGS but also scrutinizing the gluten-free dieters who believe they have it. This made its way into public media when talk show host Jimmy Kimmel set out to do his own study of gluten-free dieters in Los Angeles, who proved not very hard to find, yet somewhat uninformed as to what gluten actually is, and why it might be bad.

Results of the April publication are more specific. For instance, 24% of individuals on gluten-free diets experienced uncontrolled symptoms despite the diet, while 62% had not gone through proper celiac testing, which includes endoscopy and duodenal biopsy. Self-initiation of the gluten-free diet was a big risk factor (69%) for inadequate celiac screening, but the highest risk factor (70%) was this: initiation of the diet by an alternative health practitioner.

Joyce was correct. Errors really are volitional, and over time science always gets it right. But in the meantime, people are suffering, not just those getting the wrong treatment for IBS, but moreso the people with undiagnosed celiac sprue who actually do need to be gluten-free.

David Warmflash, M.D., is an astrobiologist, science writer, and physician. He is principal investigator on a Planetary Society-sponsored investigation of the effects of the space environment on organisms.