Gluten-free diets have caught on in a big way—in 2015, a quarter of Americans said they had ditched gluten, a combination of proteins found in wheat, rye, barley, oats, and other related grains. That number is up 67 percent since 2013. And foods proudly sporting ‘Gluten Free!’ labels have sprouted in nearly every aisle of grocery stores.

The trend is a boon for those suffering from celiac disease, a gluten-sensitive autoimmune disorder.  But that’s just about one percent or so of the US. The trend is really driven by the idea that going gluten free is good for everyone’s health—it reduces inflammation, many abstainers believe.

The problem is that scientists have yet to solidly back up that idea. And new research hints that the diet may actually pose some unexpected health risks