Like most medical interventions, though, this one has not been shown (in placebo-controlled studies) to benefit people who do not have the disease. Celiac disease is known to affect about one percent of people. Yet in a global survey of 30,000 people last year, fully 21 percent said that “gluten free” was a “very important” characteristic in their food choices. Among Millennials, the number is closer to one in three. The tendency to “avoid gluten” persists across socioeconomic strata, in households earning more than $75,000 just the same as those earning less than $30,000, and almost evenly among educational attainment. The most common justification for doing so: “no reason.”
In the medical journal, Reilly’s message is that physicians should be educating people that this is not okay. “You have the gluten-free industry speaking with a megaphone,” she said, “and we're trying to do our part to put accurate information into circulation.”
It’s in that context that she addresses the many risks that come with taking on a gluten-free diet when it is not medically warranted. That includes studies that have found increased rates of metabolic syndrome among people who switch to a gluten-free diet, presumably due to poor nutritional quality of gluten-free replica products. Other studies have reported people developing deficiencies in folate, thiamine, and iron, which are added to grain products by law. When researchers in Spain compared 206 gluten-free food products to their traditional gluten-containing counterparts, the team found “marked differences” in the nutrient and caloric contents. “This may represent a nutritional concern for celiac patients,” the researchers concluded, “but it may also be a problem for non-celiacs who consume gluten-free rendered foods.”
For parents concerned about arsenic in rice, Reilly regularly advises that many gluten-free products replace grain products with rice (which she sometimes refers to as “secret rice”). To minimize risk of arsenic exposure, the American Academy of Pediatrics recommends that kids simply eat a diverse diet. Eliminating all foods that contain gluten makes that goal only more difficult.
Among people of all ages, she notes, several small studies have now found deterioration in quality of life after the switch. For children especially, imposing a gluten-free diet can be socially isolating. In the journal Pediatrics, kids with celiac disease who attended a week-long gluten-free camp, where every food was gluten free by default, “demonstrated improvement in well-being, self-perception, and emotional outlook”—which seemed to be because the environment “alleviate[d] stress and anxiety around food and social interactions.”
Life is not gluten-free camp, though. In the real world, gluten-free versions of foods are most often more expensive than the standard formulations, as well. (An especially pointed factor for the 20 percent of households earning less than $30,000 annually and yet worrying about procuring gluten-free products.)