Grain Brains and Wheat Bellies
The focus on gluten avoidance in the United States was fomented by two popular but controversial diet books, which urge everyone to cut out wheat. Cardiologist William Davis, M.D., argues in his best-selling 2011 book, Wheat Belly, that all wheat is bad for you, whether it is whole grain or refined. Davis claims that modern wheat is nothing like the grains we evolved to eat, and that today's wheat is both addictive and toxic because of its gluten as well as other compounds. He asserts that cutting this "frankenwheat" out of your diet can shrink your belly and fight a wide range of health problems, from diabetes to schizophrenia. In 2012, Davis appeared on The Dr. Oz Show to spread the grain-free gospel far and wide.
Many experts have pointed out in the popular press, health media, and other outlets that Davis's claims do not have sound scientific backing. Davis has been criticized for cherry-picking data and referencing studies that are small or methodologically flawed. For example, in referencing a 2011 review of the literature by the well- regarded celiac expert Alessio Fasano of the University of Maryland, Davis asserted that undigested gliadin a protein component of gluten) can make the intestines leak and trigger autoimmune diseases such as Hashimoto's thyroiditis and type 1 diabetes. But he fails to mention three crucial caveats. First, Fasano's review discusses the involvement of gliadin only in celiac disease and type 1 diabetes, which often co-occur. Second, gliadin has been shown to damage the intestines only of people who are genetically predisposed to these diseases-and fewer than 10% of such people actually develop the autoimmune conditions. Third, Fasano concluded that "loss of intestinal barrier function is necessary but not sufficient for the onset of the autoimmune process." Fasano and other celiac experts, such as Daniel Leffler of Beth Israel Deaconess Medical Center in Boston, have rejected Davis's idea that modern wheat is toxic for every one. As Leffler told NPR in 2013, "There's good evidence that the vast majority of people actually do just fine with wheat."
A second influential book, Grain Brain (2013) by David Perlmutter, a neurologist at the University of Miami, argues that all grains-not just refined carbohydrates but also supposedly healthy whole grains-can cause disorders like dementia, attention deficit disorder, anxiety, depression, chronic headaches, and other health problems. Like Davis, Perlmutter was given a huge audience and, some say, an implicit endorsement by Dr. Oz -dubbed "the most trusted doctor in America" by The New Yorker and "America's doctor" by Oprah Winfrey but chastised by U.S. senators and other scientists for dispensing dubious advice. A 2014 study of Dr. Oz's show by a large group of physicians concluded that "approximately half of the recommendations have either no evidence or are contradicted by the best-available evidence." Those recommendations are hugely influential nonetheless.
Moreover, the negative press for gluten and grains has been reinforced by numerous celebrities who have touted the gluten-free diet as a way to lose weight and feel better. Gwyneth Paltrow, who recently published a gluten-free cookbook, has said going gluten-free makes her feel lighter, more relaxed, and less angry. Singer/songwriter Miley Cyrus wrote to her millions of followers on Twitter in April 2012, "Everyone should try no gluten for a week! The change in your skin, physical and mental health is amazing!".
Thanks in part to celebrity endorsements, the fad has reached beyond the United States to Europe, where celiac disease has been recognized for longer and where a trend for eating gluten-free theoretically should have come and gone much earlier. In fact, the growth in the market for gluten-free products in Europe is the second fastest in the world, just behind the United States. The market in Australia is also highly lucrative, and a similar percentage of Australians as Americans report they are avoiding gluten. This growth has been driven in part by the manufacturers themselves, who are positioning gluten-free foods as healthy choices for everyone rather than as specialized medical products (There are some exceptions, of course-mainly Italy, where gluten-free foods are widely available but generally viewed as being only for celiac patients.)
The science, however, does not support adoption of a gluten-free diet for the general population. As of this writing, no controlled studies demonstrate that gluten-free diets can lead to weight loss in people who do not have celiac disease or nonceliac gluten sensitivity. In contrast, some studies indicate that among people who have celiac disease, a significant percentage of overweight or obese dieters are likely to gain weight when they go gluten-free (probably because their
intestinal lining heals and better absorbs nutrients). Moreover, some researchers have hypothesized that indigestible starches in wheat, such as oligofructose and inulin, may actually provide some health benefits by promoting healthy gastrointestinal microbiota. But evidence for this idea is still thin and preliminary.
Popular diet books notwithstanding, science offers no reason to eliminate gluten from your diet unless you have been diagnosed with celiac disease or a wheat allergy.
Decide for Yourself
The sagas of fibers, fats, salts, carbohydrates whole grains, added sugars, and gluten teach us that it is very difficult to get the truth about the health implications of dietary choices. Three main factors cloud the issues. First, it takes a long time and a lot of money to rigorously test the benefits of a dietary system. Second, industrial food companies and advocates can make a very good living promoting claims, substantiated or not, about dietary systems. Third, even when ideas are proved to be false, they tend to linger as part of the conventional wisdom or popular viewpoint. Advocates want to keep selling diet books, nutrition experts hate to admit that they are wrong, doctors and health organizations want to maintain an aura of authority, and food companies want to keep selling products for which they can claim health benefits.
Today, we know that butter seems to be okay, but trans-fat-laden margarine could kill you just the opposite of the conventional wisdom a generation ago. As medical science gains more under standing of the underlying causes of heart disease, cancer, stroke, and other common diseases, we may learn that there are some other real villains in what we eat. But it is also possible that we will find that some of these diseases are, by and large, unrelated to diet.
Eventually, science will figure all this out, but, until it does, the safest thing to say is that proof requires large, randomized clinical trials that take many years. Until the results of those are in, one can entertain lots of opinions but reach no genuine scientific closure on the issues.
Of course, science isn't the only measure by which people make dietary decisions. These matters involve cultural and religious traditions and one's palate, as well as health considerations. People often get emotional when discussing food preferences; they may see themselves as protectors of the health of their families or patrons, or they may have a deep attachment to a certain way of eating.
Bakers and consumers must base their judgments on their personal experiences as well as the available facts-which we hope you are now better able to distinguish from hyperbole. If you're a professional baker, you're likely to encounter people who adhere to many of the dietary systems we've mentioned. Some of these people may genuinely need gluten-free bread because they have celiac disease. Others who think whole grains are better, for example, may accuse you of killing people by using refined grains in your baking. Based on the best-available science, you can accurately say that there is no clear evidence linking any beneficial health effects to whole grain consumption, low-carbohydrate diets, raw foods, no-sugar-added diets, or for the general public gluten-free diets. People who have celiac disease should strictly avoid gluten-but perhaps in the coming years, enzyme therapies or other medications will be able to mitigate the damage gluten causes in those with the disease. People who merely suspect they have a gluten intolerance may, in fact, be reacting to something else in their food-possibly FODMAPs- but the science is still emerging.
If you believe you have a food intolerance, now you know how to get tested, which tests are scientifically sound, and why self-diagnosis is so tricky. You can also decide that you're just happier avoiding whatever food makes you uncomfortable-and that's a perfectly valid choice. Personal preference is a legitimate reason for choosing to eat a certain way. We simply argue that if you are going to use health as your justification, you owe it to yourself to be aware of the best-available science. That means relying primarily on results from large randomized trials-not on media articles or popular diet books, which may simply report attention grabbing findings from low quality studies.
The uncertainty of much of that science underscores the importance of a diversified diet, which is unlikely to cause overconsumption of any truly harmful substances (like trans fat). Here's another good reason to avoid following nutrition trends: you will likely save money by not buying the latest "it" foods, which often come with a hefty price tag.
As food enthusiasts and practitioners of Modernist cuisine, we hope you feel more confident in making choices about the food you eat and serve while not begrudging yourself the pleasure of new food experiences.