In fact, not only does gluten not cause heart disease in the general population, but people who go gluten-free seem to actually be putting themselves at an increased risk of heart disease, insofar as it means eating fewer whole grains. This discovery is among those slowly painting a picture of a diverse array of harms that come with blindly avoiding gluten. The finding comes from a group of prominent nutrition and gastrointestinal researchers at Harvard and Columbia. In a prospective cohort study in the latest BMJ, they concluded that people without celiac disease “should not be encouraged” to adopt gluten-free diets.

In the language of academia, that’s a stern admonition. It’s coming late, though, and it’s less compelling than the myriad promises in glossy magazines and miracle books and celebrity-endorsed facial creams. The scientists’ advice is at odds with the fact that gluten-free diets are promoted everywhere and Googled more frequently than any other diet. By my own rough estimate, in April some $700 quadrillion in gluten-free products were sold in California alone.

Still, the new research is among the most meaningful to date on the relationship between gluten intake and health outcomes in people without celiac disease. It is based on data from more than 100,000 people over almost two decades.

Outside of this, the few small trials that have been done to study the effects of gluten intake—in which blinded participants are divided into gluten-free and gluten-containing diets and then monitored for symptoms—have been short-term and small. A study like this new one can look at dietary patterns in real life and health outcomes over the course of decades. The strongest evidence in gluten’s favor is that the longest-lived, healthiest populations on Earth have long eaten diets that include grain products. No study has yet suggested that gluten causes heart disease.

So why was this being studied at all?

The lead researcher is Benjamin Lebwohl, a gastroenterologist with the Celiac Disease Center at Columbia University. He has spent more time thinking about the societal role of gluten than anyone I’ve met before. “If we’re going to consider science as orthogonal to whatever the public is doing, it’s just going to worsen polarization,” he said. “We’ll just continue to talk past each other.”

In talking to patients, he notes an important difference between saying that there’s no proof that gluten has health effects in the general population and saying that there is proof that gluten has no health effects in the general population. To a concerned patient, that distinction can be huge.

I talked with Lebwohl one morning recently in the hours before he started scoping, as he put it, or performing endoscopies and colonoscopies, looking through a fiberoptic tube at the parts of us most of us never see. There he has come to understand that celiac disease––and the effects of gluten––are still largely mysterious.