Jessica Kendrick

Just after Labor Day, the Gluten and Allergen Free Expo stopped for a weekend at the Meadowlands Exposition Center. Each year, the event wends its way across the country like a travelling medicine show, billing itself as the largest display of gluten-free products in the United States. Banners hung from the rafters, with welcoming messages like “Plantain Flour Is the New Kale.” Plantain flour contains no gluten, and neither did anything else at the exposition (including kale). There were gluten-free chips, gluten-free dips, gluten-free soups, and gluten-free stews; there were gluten-free breads, croutons, pretzels, and beer. There was gluten-free artisanal fusilli and penne from Italy, and gluten-free artisanal fusilli and penne from the United States. Dozens of companies had set up tables, offering samples of gluten-free cheese sticks, fish sticks, bread sticks, and soy sticks. One man passed out packets of bread crumbs, made by “master bakers,” that were certified as gluten-free, G.M.O.-free, and kosher. There was even gluten-free dog food.

Gluten, one of the most heavily consumed proteins on earth, is created when two molecules, glutenin and gliadin, come into contact and form a bond. When bakers knead dough, that bond creates an elastic membrane, which is what gives bread its chewy texture and permits pizza chefs to toss and twirl the dough into the air. Gluten also traps carbon dioxide, which, as it ferments, adds volume to the loaf. Humans have been eating wheat, and the gluten in it, for at least ten thousand years. For people with celiac disease—about one per cent of the population—the briefest exposure to gluten can trigger an immune reaction powerful enough to severely damage the brushlike surfaces of the small intestine. People with celiac have to be alert around food at all times, learning to spot hidden hazards in common products, such as hydrolyzed vegetable protein and malt vinegar. Eating in restaurants requires particular vigilance. Even reusing water in which wheat pasta has been cooked can be dangerous.

Until about a decade ago, the other ninety-nine per cent of Americans rarely seemed to give gluten much thought. But, led by people like William Davis, a cardiologist whose book “Wheat Belly” created an empire founded on the conviction that gluten is a poison, the protein has become a culinary villain. Davis believes that even “healthy” whole grains are destructive, and he has blamed gluten for everything from arthritis and asthma to multiple sclerosis and schizophrenia. David Perlmutter, a neurologist and the author of another of the gluten-free movement’s foundational texts, “Grain Brain: The Surprising Truth About Wheat, Carbs, and Sugar—Your Brain’s Silent Killers,” goes further still. Gluten sensitivity, he writes, “represents one of the greatest and most under-recognized health threats to humanity.’’

Nearly twenty million people contend that they regularly experience distress after eating products that contain gluten, and a third of American adults say that they are trying to eliminate it from their diets. One study that tracks American restaurant trends found that customers ordered more than two hundred million dishes last year that were gluten- or wheat-free. (Gluten is also found in rye and barley; a gluten-free diet contains neither these grains nor wheat.) The syndrome has even acquired a name: non-celiac gluten sensitivity. “I’ve been gluten-free these last four years, and it has changed my life,’’ Marie Papp, a photographer, told me at the expo. “I would have headaches, nausea, trouble sleeping. I know that I’m intolerant because I gave it up and I felt better. That explanation is probably not scientific enough for you. But I know how I felt, how I feel, and what I did to make it change.” She went on, “I’m a foodie. It’s been five years since I had biscotti. And I just had one here, gluten-free. And it rocks.”

Sales of gluten-free products will exceed fifteen billion dollars by 2016, twice the amount of five years earlier. The growing list of gluten-free options has been a gift for many children, who no longer have to go through life knowing that they will never eat pizza, cookies, or cake. As with organic food, which was at first sold almost exclusively by outlets with a local clientele, the market is controlled increasingly by corporations. Goya and ShopRite both had booths at the expo; so did Glutino, which was founded in 1983 and has grown into a gluten-free conglomerate. “There were a lot of smaller gluten-free companies that were mom-and-pop-type shops,” Steven Singer, the co-founder of Glutino, said in an interview last month with the Globe and Mail. “So they had, like, a baking mix or a cookie mix, and they were all great people, but there was no business. And that is what drove us, the idea of being that one-stop shop in gluten-free, the category leader, the category captain.”

For many people, avoiding gluten has become a cultural as well as a dietary choice, and the exposition offered an entry ramp to a new kind of life. There was a travel agent who specialized in gluten-free vacations, and a woman who helps plan gluten-free wedding receptions. One vender passed out placards: “I am nut free,” “I am shellfish free,” “I am egg free,” “I am wheat free.” I also saw an advertisement for gluten-free communion wafers.

The fear of gluten has become so pronounced that, a few weeks ago, the television show “South Park” devoted an episode to the issue. South Park became the first entirely gluten-free town in the nation. Federal agents placed anyone suspected of having been “contaminated” in quarantine at a Papa John’s surrounded by razor wire. Citizens were forced to strip their cupboards of offending foods, and an angry mob took a flamethrower to the wheat fields.

“No matter what kind of sickness has taken hold of you, let’s blame gluten,’’ April Peveteaux writes in her highly entertaining book “Gluten Is My Bitch.” (Peveteaux maintains a blog with the same name.) “If you want or need to get gluten out of your diet, bravo! Kick that nasty gluten to the curb. . . . Not sure if gluten-free is for you? Perhaps gluten simply causes you some discomfort, but you’ve never been diagnosed. Then eff that gluten!’’

Wheat provides about twenty per cent of the world’s calories and more nourishment than any other source of food. Last year’s harvest, of seven hundred and eighteen million tons, amounted to roughly two hundred pounds for every person on earth. In the United States, wheat consumption appears to fluctuate according to nutritional trends. It rose steadily from the nineteen-seventies to about 2000, a reflection of the growing concern over the relationships between meat and saturated fat, cholesterol, and heart disease. Since then, the number of people who say that wheat, barley, and rye make them sick has soared, though wheat consumption has fallen.

Wheat is easy to grow, to store, and to ship. The chemical properties of flour and dough also make wheat versatile. Most people know that it is integral to bread, pasta, noodles, and cereal. But wheat has become a hidden ingredient in thousands of other products, including soups, sauces, gravies, dressings, spreads, and snack foods, and even processed meats and frozen vegetables. Nearly a third of the foods found in American supermarkets contain some component of wheat—usually gluten or starch, or both.

The most obvious question is also the most difficult to answer: How could gluten, present in a staple food that has sustained humanity for thousands of years, have suddenly become so threatening? There are many theories but no clear, scientifically satisfying answers. Some researchers argue that wheat genes have become toxic. Davis has said that bread today is nothing like the bread found on tables just fifty years ago: “What’s changed is that wheat’s adverse effects on human health have been amplified many-fold. . . .The version of ‘wheat’ we consume today is a product of genetic research. . . . You and I cannot, to any degree, obtain the forms of wheat that were grown fifty years ago, let alone one hundred, one thousand, or ten thousand years ago. . . . We have to restrict other carbohydrates beyond wheat, but wheat still stands apart as the worst of the worst.’’ Perlmutter is less restrained: “As many as forty percent of us can’t properly process gluten, and the remaining sixty percent could be in harm’s way.”

Although dietary patterns have changed dramatically in the past century, our genes have not. The human body has not evolved to consume a modern Western diet, with meals full of sugary substances and refined, high-calorie carbohydrates. Moreover, most of the wheat we eat today has been milled into white flour, which has plenty of gluten but few vitamins or nutrients, and can cause the sharp increases in blood sugar that often lead to diabetes and other chronic diseases.

Donald Kasarda, a researcher at the U.S. Department of Agriculture, has studied wheat genetics for decades. In a recent study published in the Journal of Agricultural and Food Chemistry, he found no evidence that a change in wheat-breeding practices might have led to an increase in the incidence of celiac disease. “My survey of protein content in wheat in the U.S. over approximately the past one hundred years did not support such an increase on the basis of historical data in comparison with recent data,’’ he subsequently told an interviewer.

Joseph A. Murray, a professor of medicine at the Mayo Clinic and the president of the North American Society for the Study of Celiac Disease, has also studied wheat genetics. He agrees with Kasarda. “The wheat grain is not a lot different than it was fifty years ago,’’ Murray told me. “Chemically, the contents just have not changed much. And there is something more important to note. Wheat consumption is going down, not up. I don’t think this is a problem that can be linked to the genetics of wheat.”

But something strange is clearly going on. For reasons that remain largely unexplained, the incidence of celiac disease has increased more than fourfold in the past sixty years. Researchers initially attributed the growing number of cases to greater public awareness and better diagnoses. But neither can fully account for the leap since 1950. Murray and his colleagues at the Mayo Clinic discovered the increase almost by accident. Murray wanted to examine the long-term effects of undiagnosed celiac disease. To do that, he analyzed blood samples that had been taken from nine thousand Air Force recruits between 1948 and 1954. The researchers looked for antibodies to an enzyme called transglutaminase; they are a reliable marker for celiac disease. Murray assumed that one per cent of the soldiers would test positive, matching the current celiac rate. Instead, the team found the antibodies in the blood of just two-tenths of one per cent of the soldiers. Then they compared the results with samples taken recently from demographically similar groups of twenty- and seventy-year-old men. In both groups, the biochemical markers were present in about one per cent of the samples.

“That suggested that whatever has happened with celiac disease has happened since 1950,’’ Murray said. “The increase affected young and old people equally.” These results imply that the cause is environmental.

Nobody can say for sure why the rise in celiac disease has been so rapid. The modern diet may be to blame. And there is also growing evidence, in animal studies and in humans, that our microbiome—the many bacterial species inhabiting our gut—can have a significant impact on a range of diseases. None of that, however, explains why so many people who don’t have celiac disease feel the need to give up gluten.

Gluten anxiety has been building for years, but it didn’t become acute until 2011, when a group led by Peter Gibson, a professor of gastroenterology at Monash University and the director of the G.I. unit at the Alfred Hospital, in Melbourne, seemed to provide evidence that gluten was capable of causing illness even in people who did not have celiac disease. Gibson and his colleagues recruited thirty-four people with irritable-bowel syndrome, all of whom had complained of stomach ailments that largely disappeared when they stopped eating gluten. He put them all on a strictly monitored gluten-free diet, but, unbeknownst to the subjects, about half got muffins and bread with gluten. It was a double-blind study, so neither the doctors nor the patients knew which muffins and bread contained gluten. But most of those who ate the gluten reported that the pain returned; for most of the others it did not. The study was small but meticulous, and the results were compelling. Several similar studies are now under way, but dietary research is notoriously time-consuming and difficult.

Gibson published his findings in the American Journal of Gastroenterology, but, along with other experts, he urged restraint in interpreting data from such a small study. Nevertheless, millions of people with vague symptoms of gastric distress suddenly found something concrete for which to blame their troubles. The market boomed, but the essential mystery remained unsolved: Why was gluten suddenly so hazardous? Perhaps, researchers thought, farmers had increased the protein (and gluten) content of wheat so drastically that people could no longer digest it properly.

But there is more to wheat than gluten. Wheat also contains a combination of complex carbohydrates, and the Australian team wondered if these could be responsible for the problems. Gibson and his colleagues devised a different study: they recruited a group of thirty-seven volunteers who seemed unable to digest gluten properly. This time, the researchers attempted to rule out the carbohydrates and confirm gluten as the culprit. Gibson put all the volunteers on a diet that was gluten-free and also free of a group of carbohydrates that he and his colleagues called FODMAPs, an acronym for a series of words that few people will ever remember: fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Not all carbohydrates are considered FODMAPs, but many types of foods contain them, including foods that are high in fructose, like honey, apples, mangoes, and watermelon; dairy products, like milk and ice cream; and fructans, such as garlic and onions.

Most people have no trouble digesting FODMAPs, but these carbohydrates are osmotic, which means that they pull water into the intestinal tract. That can cause abdominal pain, bloating, and diarrhea. When the carbohydrates enter the small intestine undigested, they move on to the colon, where bacteria begin to break them down. That process causes fermentation, and one product of fermentation is gas. In Gibson’s new study, when the subjects were placed on a diet free of both gluten and FODMAPs, their gastrointestinal symptoms abated. After two weeks, all of the participants reported that they felt better. Some subjects were then secretly given food that contained gluten; the symptoms did not recur. The study provided evidence that the 2011 study was wrong—or, at least, incomplete. The cause of the symptoms seemed to be FODMAPs, not gluten; no biological markers were found in the blood, feces, or urine to suggest that gluten caused any unusual metabolic response.

In fact, FODMAPs seem more likely than gluten to cause widespread intestinal distress, since bacteria regularly ferment carbohydrates but ferment protein less frequently. Although a FODMAP-free diet is complicated, it permits people to eliminate individual foods temporarily and then reintroduce them systematically to determine which, if any, are responsible for their stomach problems. FODMAPs are not as trendy as gluten and not as easy to understand. But, biologically, their role makes more sense, Murray says.

“That first paper, in 2011, blew our minds,” Murray told me. “Essentially, it said that people are intolerant of gluten, and it was based on a well-designed, double-blind study. When people were challenged with gluten, by eating the muffins, they got sick. We just couldn’t figure it out. But then came the second study. By then, it was almost too late to put the genie back in the bottle. You have millions of people out there completely convinced that they feel better when they don’t eat gluten—and they don’t want to hear anything different.”

The FODMAP research, while influential and highly regarded, involved fewer than a hundred people, not enough to account definitively for the number of people who have abandoned foods that contain gluten. Several groups are trying to repeat those results. But studies like that take time. At present, there are no blood tests, biopsies, genetic markers, or antibodies that can confirm a diagnosis of non-celiac gluten sensitivity. There have been a few studies suggesting that people without celiac disease have a reason to eliminate gluten from their diet. But most of the data are unclear or preliminary. Doctors rarely diagnose non-celiac gluten sensitivity, and many don’t believe that it exists. Few people seem to have been deterred by the lack of evidence. “Everyone is trying to figure out what is going on, but nobody in medicine, at least not in my field, thinks this adds up to anything like the number of people who say they feel better when they take gluten out of their diet,” Murray said. “It’s hard to put a number on these things, but I would have to say that at least seventy per cent of it is hype and desire. There is just nothing obviously related to gluten that is wrong with most of these people.’’

About a month ago, in an attempt to gain a better understanding of the role that gluten plays in our diet, I flew to Seattle, then drove north for an hour, to Mount Vernon, where Washington State University’s Bread Lab is situated. The lab is part of the university’s wheat-breeding program; by studying the diversity of the grains grown in the Pacific Northwest, researchers there hope to determine which are most suitable for baking, brewing, and making pasta. Dan Barber, a chef and the co-owner of the Blue Hill restaurants, in Manhattan and in Pocantico Hills, had suggested that I visit Stephen Jones, a molecular cytogeneticist and the lab’s director. Barber, in his recent book “The Third Plate,” describes Jones as a savior of traditional wheat in a world that has transformed most crops into bland industrial commodities. I was more eager to hear what he had to say about the implications of adding extra gluten to bread dough, which has become routine in industrial bakeries.

Jones, a strapping man with an aw-shucks manner, has spent the past twenty-five years trying to figure out the best way to make a loaf of bread. The amount of gluten added to industrially made bread keeps increasing, and Jones has become acutely interested in whether that extra gluten may be at least partly responsible for the gastrointestinal distress reported by so many people. “My Ph.D. was on the genetics of loaf volume—looking at chromosomes and relating them to the strength of the dough in bread,’’ Jones said, as he greeted me at the entrance to the research center. The inviting, if somewhat incongruous, aroma of freshly baked bread filled the building. Jones’s lab is unique; few bakeries have Brabender farinographs, which Jones and his team use in their search for the ideal ratio of gluten to water in dough, and to measure the strength of flour. Nor can there be many labs with a Matador deck baking oven, which can accommodate more than a dozen loaves at a time, and which circulates heat uniformly, at hot enough temperatures, to insure a voluminous loaf and the strongest possible crust.

For all the high-tech gadgets on display in the Bread Lab, the operation is decidedly old-fashioned, relying on stone mills of a type that have not been used for more than a century and on a philosophy that all it takes to make genuine and delicious whole-wheat bread is time, talent, flour, a little salt, and lots of water. There are essentially two ways to turn flour into bread. The first is the way it was done for most of human history: let the flour absorb as much water as possible and give it time to ferment, a process that allows yeast and bacteria to activate the dough. Kneading then binds the two proteins that come together to form gluten. Most of the bread consumed in the United States is made the other way: in place of hydration, fermentation, and kneading, manufacturers save time by relying on artificial additives and huge industrial mixers to ram together the essential proteins that form gluten.

Until the late nineteenth century, when steel rollers and industrial mills came into use, wheat was ground on stones, a slow and imprecise process. Steel was fast, efficient, and easy to maintain, and it permitted millers to discard the germ and the bran in the wheat kernel and then rapidly process the starchy endosperm. This made white flour. Almost nobody seemed to notice, or care, that by tossing out the rest of the kernel industrial bakers were stripping bread of its vitamins, its fibre, and most of its healthy fats. White bread was seen as an affordable luxury. Like many Jews arriving from Russia at the turn of the twentieth century, my great-grandfather had never seen white bread before, but when he did he immediately made what was referred to, at least in my family, as an “American sandwich”: he took two pieces of the black bread that he had always eaten, and carefully placed a piece of industrially made white bread between them. He is said to have been delighted.

The Bread Lab team, which includes the patient, inventive baker Jonathan Bethony, uses whole grains, water, salt, and yeast. Nothing else. Whole-wheat bread, even when it’s good, is usually dense and chewy, and rarely moist; Bethony’s bread was remarkably airy and light. It contains only the natural gluten formed by kneading the flour. Most bakers, even those who would never go near an industrial mixing machine, include an additive called vital wheat gluten to strengthen the dough and to help the loaf rise. (In general, the higher the protein content of wheat, the more gluten it contains.)

Vital wheat gluten is a powdered, concentrated form of the gluten that is found naturally in all bread. It is made by washing wheat flour with water until the starches dissolve. Bakers add extra gluten to their dough to provide the strength and elasticity necessary for it to endure the often brutal process of commercial mixing. Vital wheat gluten increases shelf life and acts as a binder; because it’s so versatile, food companies have added it not only to bread but to pastas, snacks, cereals, and crackers, and as a thickener in hundreds of foods and even in some cosmetics. Chemically, vital wheat gluten is identical to regular gluten, and no more likely to cause harm. But the fact that it is added to the protein already in the flour worries Jones. “Vital wheat gluten is a crutch,’’ he said. “It’s all storage and functionality. No flavor. People act as if it were magic. But there is no magic to food.”

Jones is a careful scientist, and he said more than once that he had no evidence that a growing reliance on any single additive could explain why celiac disease has become more common, or why so many people say that they have trouble digesting gluten. But he and his colleagues are certain that vital wheat gluten makes bread taste like mush. “Flour that is sliced and packed into plastic wrapping in less than three hours—that’s not bread,’’ Jones said. He and Bethany Econopouly, one of his doctoral students, recently published an essay in the Huffington Post in which they argue that the legal definition of the word “bread” has become meaningless and ought to be changed: “FDA regulations state that for bread to be labeled as ‘bread,’ it must be made of flour, yeast, and a moistening ingredient, usually water. When bleached flour is used, chemicals like acetone peroxide, chlorine, and benzoyl peroxide (yes, the one used to treat acne) can be included in the recipe and are masked under the term ‘bleached.’ Optional ingredients are also permissible in products called bread: shortening, sweeteners, ground dehulled soybeans, coloring, potassium bromate . . . and other dough strengtheners (such as bleaching agents and vital gluten).”

Could millions of people simply be eating too much vital wheat gluten? There are no real data to answer that question, but Jones is not alone in seeking to gain a better understanding of the potential physiological impact. Joseph Murray, at the Mayo Clinic, has begun studying its effect on the immune system. Murray says, “This is a major component of the bread we eat, and we don’t know much about it. It’s very important that we figure out what effect, if any, there is when we add all that extra gluten to bread.’’

Paradoxically, the increased consumption of vital wheat gluten can be attributed, at least in part, to a demand for healthier baked goods. It is not possible to manufacture, package, and ship large amounts of industrially made whole-grain bread without adding something to help strengthen the dough. Jones refers to these products generically as “Bob’s groovy breads.’’ Look closely at labels of “healthy” whole-wheat breads, and it’s easy to understand what he means. (After my trip to Seattle, the first bread I saw that advertised itself as having been milled from hundred-per-cent whole grains contained many ingredients. The first four, listed in descending order of weight or volume, were whole-wheat flour, water, wheat gluten, and wheat fibre. In other words: gluten, water, more gluten, and fibrous gluten.) In the promotional videos for Dave’s Killer Bread, a popular brand, the founder, Dave, speaks glowingly about the properties of gluten. Pictures of the factory show pallets stacked with fifty-pound bags of vital wheat gluten. “I just wonder how much of this additional gluten our bodies can digest,’’ Jones told me when I was at the Bread Lab. “There has to be some limit.”

I was having trouble visualizing vital wheat gluten as a discrete substance. When I said that, Jones nodded at Econopouly, and she left the room. Two minutes later, she returned and handed me a shard of vital wheat gluten. It looked like a prehistoric weapon, or the hardened bone marrow of a small mammal. “We put a plug of gluten in Coke and it foamed for a while, then became a glob that sat there for weeks,’’ Jones said. “It didn’t disintegrate into slime and mush. It just stayed there.’’ He took the plug out of my hands and slapped it on the lab counter. Nothing happened. “The stuff is simply indestructible,’’ he said.

The next morning, before leaving Seattle, I stopped by the offices of Intellectual Ventures, the patent and invention factory run by Nathan Myhrvold, the former chief technology officer at Microsoft. Myhrvold has long been a serious amateur chef and has also served as a gastronomic adviser to the Zagat Survey. Three years ago, he published “Modernist Cuisine: the Art and Science of Cooking,’’ a six-volume, twenty-four-hundred-page set of books that quickly became an essential guide for chefs around the world. Since then, Myhrvold and his team have been working on an equally ambitious follow-up project, tentatively called “The Art and Science of Bread.’’ The book won’t be ready for at least another year, but Myhrvold has said that it will be both a comprehensive history of bread and an exhaustive guide to baking it.

The project’s chef, Francisco Migoya, asked me if I had ever eaten gluten by itself. I shook my head. He placed a small ball of raw gluten in a microwave and pressed start. After about twenty seconds, the gluten puffed up like a balloon, at which point it was removed, set carefully on a plate, and served. It had the texture of pork rind. Gluten has a long culinary history, and has become a common substitute for meat and tofu. In Asia, where it is particularly popular, gluten is called seitan, and it is often steamed, fried, or baked.

Myhrvold wasn’t in town that day, but I caught up with him later. He is highly opinionated, and delights in controversy; saying the words “gluten-free” to him was like waving a red flag at a bull. “When I was a kid, I would watch National Geographic specials all the time,’’ he told me. “Often, they would travel to remote places and talk to shamans about evil spirits. It was an era of true condescension; the idea was that we know better and these poor people are noble, but they think that spirits are everywhere. That is exactly what this gluten-free thing is all about.” He stressed that he was not referring to people with celiac disease or questioning the possibility that some others might also have trouble eating gluten. “For most people, this is in no way different from saying, ‘Oh, my God, we are cursed.’ We have undergone what amounts to an attack of evil spirits: gluten will destroy your brain, it will give you cancer, it will kill you. We are the same people who talk to shamans.

“To find out the effect something like gluten has on people’s diets is complicated,’’ he said. “We’ll need long-term studies, and there won’t be a useful answer for years. So, instead of telling everyone you are going on a gluten-free diet, what if you said, ‘Hey, I am going on an experimental regimen, and it will be years before we know what effect it might have.’ I don’t know about you, but instead of saying ‘Eat this because it will be good for you,’ I would say, ‘Good luck.’ ’’

Fad dieting is nothing new in America; it’s what we do instead of eating balanced, nutritiously wholesome meals. Scarsdale, Atkins, South Beach, Zone, flexitarian, pescatarian, and paleo have all been awarded their fifteen minutes of fame and then shoved aside for the next great diet. They are rarely effective for long. Some nutrition specialists say that the current preoccupation with gluten-free products reminds them of the national obsession with removing fats from foods in the late nineteen-eighties. “Low-fat” foods are often packed with sugar and calories to make up for the lack of fat. The same is true of many products that are advertised as “gluten-free.”

While there are no scientific data to demonstrate that millions of people have become allergic or intolerant to gluten (or to other wheat proteins), there is convincing and repeated evidence that dietary self-diagnoses are almost always wrong, particularly when the diagnosis extends to most of society. We still feel more comfortable relying on anecdotes and intuition than on statistics or data. Since the nineteen-sixties, for example, monosodium glutamate, or MSG, has been vilified. Even now, it is common to see Chinese restaurants advertise their food as “MSG-free.” The symptoms that MSG is purported to cause—headaches and palpitations are among the most frequently cited—were initially described as “Chinese-restaurant syndrome” in a letter published, in 1968, in The New England Journal of Medicine. The Internet is filled with sites that name the “hidden” sources of MSG. Yet, after decades of study, there is no evidence that MSG causes those symptoms or any others. This should surprise no one, since there are no chemical differences between the naturally occurring glutamate ions in our bodies and those present in the MSG we eat. Nor is MSG simply an additive: there is MSG in tomatoes, Parmesan, potatoes, mushrooms, and many other foods.

Our abject fear of eating fat has long been among the more egregious examples of the lack of connection between nutritional facts and the powerful myths that govern our eating habits. For decades, low-fat diets have been recommended for weight loss and to prevent heart disease. Food companies have altered thousands of products so that they can be labelled as low in fat, but replacing those fats with sugars, salt, and refined carbohydrates makes the food even less healthy. “Almost all of this has proved to be nonsense,’’ Myhrvold said. “Research shows that the total amount of fat in the diet isn’t really linked to weight or disease. What matters is the type of fat and the total calories you consume.” Bad fats increase the risk of death from heart disease and good fats lower it.

Margarine is a bad fat. Yet for decades doctors encouraged consumers to eat it, instead of butter, because butter is laden with saturated fat, which was considered even more dangerous than the fat in margarine. The assumption was not tested until the early nineteen-nineties, when researchers at the Harvard School of Public Health began to analyze data from the Nurses’ Health Study, which had followed the health of ninety thousand nurses for more than a decade. The study showed that women who ate four teaspoons of margarine a day had a fifty per cent greater risk of heart disease than those who rarely or never ate margarine. Yet again, the intuitive advice followed by so many people had been wrong.

Peter H. R. Green, the director of the celiac-disease center at the Columbia University medical school and one of the nation’s most prominent celiac doctors, says that the opposition to gluten has followed a similar pattern, and that it is harming at least as many people as it is helping. “This is a largely self-diagnosed disease,’’ Green said, when I visited his office, at New York-Presbyterian Hospital. “In the absence of celiac disease, physicians don’t usually tell people they are sensitive to gluten. This is becoming one of the most difficult problems that I face in my daily practice.”

He went on, “I recently saw a retired executive of an international company. He got a life coach to help him, and one of the pieces of advice the coach gave him was to get on a gluten-free diet. A life coach is prescribing a gluten-free diet. So do podiatrists, chiropractors, even psychiatrists.’’ He stopped, stood up, shook his head as if he were about to say something he shouldn’t, then shrugged and sat down again. “A friend of mine told me his wife was seeing a psychiatrist for anxiety and depression. And one of the first things the psychiatrist did was to put her on a gluten-free diet. This is getting out of hand. We are seeing more and more cases of orthorexia nervosa”—people who progressively withdraw different foods in what they perceive as an attempt to improve their health. “First, they come off gluten. Then corn. Then soy. Then tomatoes. Then milk. After a while, they don’t have anything left to eat—and they proselytize about it. Worse is what parents are doing to their children. It’s cruel and unusual treatment to put a child on a gluten-free diet without its being indicated medically. Parental perception of a child’s feeling better on a gluten-free diet is even weaker than self-perception.”

The initial appeal, and potential success, of a gluten-free diet is not hard to understand, particularly for people with genuine stomach ailments. Cutting back on foods that contain gluten often helps people reduce their consumption of refined carbohydrates, bread, beer, and other highly caloric foods. When followed carefully, those restrictions help people lose weight, particularly if they substitute foods like quinoa and lentils for the starches they had been eating. But eliminating gluten is complicated, inconvenient, and costly, and data suggest that most people don’t do it for long.

The diet can also be unhealthy. “Often, gluten-free versions of traditional wheat-based foods are actually junk food,’’ Green said. That becomes clear after a cursory glance at the labels of many gluten-free products. Ingredients like rice starch, cornstarch, tapioca starch, and potato starch are often used as replacements for white flour. But they are highly refined carbohydrates, and release at least as much sugar into the bloodstream as the foods that people have forsaken. “Our patients have jumped on this bandwagon and largely left the medical community wondering what the hell is going on,’’ Green said.

“You know, people are always dropping off samples of gluten-free products at our office. And when I eat them I regret it. I get heartburn. I feel nauseous. Because what are the things that sell food? Salt, sugar, fat, and gluten. If the makers take one away, then they add more of another to keep it attractive to people. If you don’t have celiac disease, then these diets are not going to help you.” People seem to forget that a gluten-free cake is still a cake.

I have been baking bread for more than thirty years, and there are few things I find more satisfying than turning a pound of wheat into something that I can feed to my friends. But it’s not always easy to believe in gluten these days. A couple of years ago, having learned that the nutrients and vitamins in wheat berries begin to degrade soon after they are processed, I bought a home mill and began to make my own flour. I started ordering wheat, in fifty-pound buckets, from places in Montana and South Dakota. I bought books that explained the differences between hard red winter wheat, which is good for whole-grain bread, and soft white wheat, which has a lower protein content and is used mostly for cookies, cakes, and pastries. I acquired sourdough starter from a friend, and treat it like a pet.

I have run into a couple of problems, however. The first was technical: I couldn’t make the wheat rise. I decided early on to bake only whole-wheat bread, but there just wasn’t enough protein in any combination of the grains I used. The bread often looked like brown matzoh, so I began to root around the Internet, and soon stumbled on the solution: vital wheat gluten. (“If you want to keep your bread 100% whole wheat, vital wheat gluten is your new best friend,’’ a message on one bread forum said. “This stuff is super-concentrated gluten flour, and it really helps to give low-gluten doughs better structure.”) That turned out to be true. It was like pumping air into a flat tire. A few tablespoons mixed into my flour, and the bread became elastic and chewy, and it looked like a normal loaf of bread; vital wheat gluten became my magic wand. Gradually, another problem arose, as more and more of my friends began to say, “Thanks, but I am staying away from gluten these days.”

I told Jonathan Bethony, the baker at the Bread Lab, about my gluten issue. Then he told me about his. “I went into baking because I thought it was a wholesome form of expression,’’ he said while kneading a loaf he would bake the next day. “I kept hearing about this gluten thing all the time. How gluten was so dangerous, and it was really getting me down in my heart. I started to ask myself, Am I making people sick? Have I become this spear of death?’’ He began to think about a different profession.

“It came to a head one day while I was working at a groovy natural health-food store in the Bay Area,” he went on. “My wife came home from work and said, ‘Sweetie, there is something I have to tell you. The doctor said that I am gluten intolerant. I can’t eat bread anymore.’ ” Bethony looked up from his dough. “I held it in as long as I could, but I just lost it. I had brought a loaf home with me, and I went charging up the stairs as fast as I could and launched that loaf from the balcony like a football.’’ Now Bethony wondered whether he ought to quit. But a famous baker lived nearby, and encouraged him to stick with it. He taught him to bake with nothing but whole grains and lots of water, and to leave plenty of time for the bread to ferment. The results have been sublime.

Later that week, I flew back to New York, went home, and dumped my vital wheat gluten in the trash. I have returned to baking whole-wheat bread the way it is supposed to be made: water, yeast, flour, and salt. I will try to live without the magic wand. But I am certainly not going to live without gluten. That just seems silly. ♦