Science Has Begun Taking Gluten Seriously
New research from Harvard and Columbia says gluten does not cause heart disease. Why is that even a question?
Every year more money is being spent studying the now-infamous plant protein gluten. The studying raises more questions. That leads to more money being spent. And then more questions.
If there was more than one lecture in medical school where gluten came up, I don’t remember it. The one I remember was in 2007, in the context of celiac disease. After the lecturer mentioned “gluten,” a classmate raised a hand and asked him to repeat himself. People who eat what?
Of course gluten, which comes from wheat, rye, and barley, was all around us then, as it is now. It’s a sort of mortar in the walls of the modern food system, in so much of what we eat or otherwise ingest and apply to ourselves. But we were barely, if at all, aware of it.
When someone with celiac disease eats gluten, it causes an immune reaction that destroys the lining of the small intestine. But as long as people with celiac disease avoid gluten, they’re fine. Got it. And like most medical doctors, that’s what I remember learning about gluten.
Cut to a decade later, and this month there is a headline that says eating gluten doesn’t cause people to develop heart disease.
Heart disease. I don’t actually have a “no shit” folder but my trained impulse was to commandeer a file cabinet and start one. I’d also put a study there that said gluten doesn’t cause rickets or global warming. Why or how would gluten cause heart disease?
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.
The textbook take on celiac disease is still that it’s an autoimmune condition. It is usually diagnosed by testing for antibodies called tissue-transglutaminase, and by taking a biopsy of a person’s small intestine after the person has eaten gluten. If a person has celiac disease, then Lebwohl expects to see that the finger-like villi of the intestinal wall have been obliterated, flattened like a mowed lawn.
But sometimes things get strange. Some of the people Lebwohl sees who have severe atrophy of their intestinal villi eat gluten and feel totally fine. It’s only when they stop eating gluten, and then are exposed to it at some later point, that symptoms arise.
He and the rest of the celiac team at Columbia also see many, many cases of the inverse: people with normal-looking bowel walls who feel horrible when they eat gluten.
“Why is gluten making people without celiac disease ill?” Lebwohl asks rhetorically. “And why is there such variability in symptoms among people with celiac disease when they eat gluten? There are people that appear to have symptoms that are triggered by gluten, but they definitely do not have celiac disease. This is likely because it’s a new disorder, one for which we don’t have good biomarkers [lab tests] and don’t have an understanding of its mechanism.”
The condition likely involves some degree of placebo and nocebo effects, and variations in intestinal flora probably also play a part. He also notes that symptoms may actually be related to FODMAPs—an increasingly popular acronym for a group of carbohydrates that some believe are actually the cause of the symptoms that many people attribute to gluten (or to dairy or soy, et cetera, or simply chalk them up to “irritable bowel syndrome”). And nothing about these explanations is mutually exclusive.
“There’s also a good chance that there’s a distinct clinical entity out there we just haven’t discovered yet,” he said. “If that’s the case, we have a choice. We can roll our eyes and say this isn’t in the medical textbooks, which often then drives patients to ‘alternative’ practitioners, and they start taking multiple supplements, or we can listen and study these patients.”
Lebwohl spent his undergraduate years at Harvard studying music. After four years of medical school, four years of residency, and three years of fellowship, he did a masters degree in patient-oriented research at Columbia, and a post-doctoral fellowship in cancer-related population sciences. He came out the other end less developed than he imagined—less prepared to care for people who exist in the real world than he imagined.
“After all that, I realized that people were asking me about ‘leaky gut’ and candida,” he said. “I had zero exposure to any of these concepts, or how to approach patients who are coming to you with concepts that are totally foreign to medical training.”
I’ve felt the same, and I know my classmates have. When I write about these things that people ask about—like cryotherapy or chelation therapy or lectin-free dieting—I inevitably hear from science-minded readers who are concerned that these subjects are not worthy of any coverage at all. The best course is to simply ignore them.
Lebwohl’s team—which includes veteran researchers like Harvard’s Walter Willett—see it otherwise. They decided to devote their time and money to studying the relationship between gluten and heart disease not because it seemed that they could be plausibly related, but simply because people believe them to be. And they believe this because of a monstrously popular 2011 book called Wheat Belly, which includes the implication that eating gluten has adverse cardiovascular effects.
The book was written by William Davis, who is a cardiologist based in Milwaukee, but whose concern about grains is substantially out of proportion to that of academic medicine on the whole. For example, he has likened eating wheat to smoking. One post on his blog warns: “Whole grains are indeed healthier than white flour products—just as filtered cigarettes are healthier than unfiltered cigarettes.”
Though blindly avoiding gluten is not recommended by any body of cardiologists or preventive-medicine experts, the outsider status of Davis’s alarmist hypothesis was promoted as the angle that seems to have made his book enormously successful. He promised readers secrets that few others were willing to tell them, and superiority to the sheep who had been played by the system. This narrative tends to sell. I’ve previously traced the modern multi-billion-dollar gluten-free obsession to Wheat Belly, which is published by Rodale, along with subsequent spinoff books in the franchise. (Wheat Belly Total Health: The Ultimate Grain-Free Health and Weight-Loss Life Plan; Wheat Belly 30-Minute (Or Less!) Cookbook: 200 Quick and Simple Recipes to Lose the Wheat, Lose the Weight, and Find Your Path Back to Health; Wheat Belly 10-Day Grain Detox: Reprogram your body for rapid Weight Loss and Amazing Health, and Wheat Belly Cookbook: 150 Recipes to Help You Lose the Wheat, Lose the Weight, and Find Your Path Back to Health.)
In all, five books to tell people to stop eating grains. The accomplice to Wheat Belly was the comparably fictive 2012 Grain Brain, the author of which has called gluten “this generation’s tobacco,” and which also became a number-one bestseller by promising secrets that no one else was willing to tell us, namely that avoiding grains would prevent and reverse dementia. It’s also based on the idea that gluten sensitivity causes inflammation throughout a person’s body, which has not been shown to be true. The idea has been picked up by theorists and presented as certainty, though, even the founder of The Ultrawellness Center and embattled doctor to the Clintons, Mark Hyman, who has written that even in the absence of celiac disease, gluten “creates inflammation throughout the body, with wide-ranging effects across all organ systems including your brain, heart, joints, digestive tract, and more.” According to his web site, he has written ten books that were number-one bestsellers.
Davis’s publicist said he was unavailable for comment in time for this story, as he was doing a radio interview and then driving to Cleveland as part of a press tour for his new book. This new one is a break from the franchise in name, but not in subversive tone. It’s called Undoctored: Why Health Care Has Failed You and How You Can Become Smarter Than Your Doctor. The title is not hyperbolic. The text literally sells superiority: “Let’s be absolutely clear: I propose that people can manage their own health safely and responsibly and attain results superior to those achieved through conventional health care—not less than, not on par with, but superior.”
This is the same anti-establishment, outsider spirit that sent Davis’s first book to the number-one spot on The New York Times bestseller list and brought “gluten free” to such a pitch that it can now be found as one of very few nutritional distinctions on restaurant menus around the world. At a time when some best-selling books sell just a few thousand copies, Wheat Belly has sold more than a million.
“In that book, a lot of the science from celiac disease has been sort of co-opted and extrapolated into the general population,” said Lebwohl. “Like the notion that gluten is intrinsically pro-inflammatory. That’s something for which we have very shaky data.”
But since people believe the story, these ideas are now the topics of serious study. They came to popularity among crowds that felt alienated and unheard, and so were susceptible to demagoguery, and now a medical establishment that has long been seen as elitist and closed-minded is paying for the power dynamic it created.
The funding for the new gluten-heart-disease study came from grants from the American Gastroenterological Association, Massachusetts General Hospital, and the National Institutes of Health. Any entrenched system is going to have a backlash; in the case of gluten, the rebellion is now leading the discourse. The team at Columbia is now working on another study looking for any relationship between gluten and cancer. (They have no reason to think that gluten causes cancer. But some people do believe this.)
“I believe we need to research and study rigorously the things that patients are interested in,” said Lebwohl. “This is, in my view, a necessary part of science’s mission—to go to where the public is interested and provide sound analysis. If the public is barking up the wrong tree, we shouldn’t ignore that.”
Some find this concerning—that we’ve entered a cycle of buying and belief that will require so much research that science will never catch up, but only ever be chasing whatever people have already chosen to believe gluten is doing to them. Others say this is exactly how science is supposed to work.
In the meantime, Lebwohl tells gluten-wary patients to be wary, rather, of “any practitioner who is telling people that the problem is that their gut is leaking.” And as a general rule, “beware of any lab tests that tell you what foods you can’t tolerate. If there is a lab that does tests that can’t be paid for by conventional means––insurance companies––maybe that lab is testing things that are totally unproven. There are countless people who will take advantage of those who are looking for answers right now.”