An increasing number of Americans are eating gluten-free despite not having celiac disease, the main medical reason for adopting such a diet.  Between 2009-10, when 0.52% of the population ate gluten-free despite not having celiac disease, and 2013-14, when 1.69% did so, the proportion more than tripled, according to a new study published on Tuesday in the Journal of the American Medical Association Internal Medicine.  A gluten-free diet is the only treatment for celiac disease, though its use by those without a celiac diagnosis has often been debated.  Between 2009-10 and 2013-14 the proportion of the 22,278 Americans surveyed in the study with celiac disease stayed roughly constant at 0.7% in 2009-10, 0.77% in 2011-12 and 0.58% in 2013-14.  The increase in those without celiac disease who kept a gluten-free diet was especially pronounced for women (rising from 0.59% to 2.15%) and 20- to 39-year-olds (rising from 0.37% to 2.42%).  The researchers from the Rutgers New Jersey Medical School examined data from the Center for Disease Control’s National Health and Nutrition Examination Survey (NHANES), which combined interviews and physical examinations. All subjects underwent serologic testing for celiac disease, which examines antibodies in the blood, to determine whether they did or did not have celiac disease, and were asked about prior diagnosis and their adherence to a gluten-free diet. The study was limited by the small number of people identified by the NHANES as having celiac disease or adhering to a gluten-free diet.  Other research has used this data before to analyze the prevalence of non-celiac gluten-free diets, though Dr Hyun-seok Kim, this study’s lead researcher, said none has used this range of data “to investigate time trends”. A 2013 study, for example, looked at the NHANES data in 2009-10, and used the percentage of those who did not have celiac disease yet kept a gluten-free diet as a “surrogate marker” for non-celiac gluten sensitivity, a condition which exhibits similar symptoms to celiac disease. The Rutgers study did not examine non-celiac gluten sensitivity.  Celiac disease is an autoimmune disorder which is said to affect approximately 1% of the population – though most are unaware that they have it. For those with the condition, eating gluten, a protein found in wheat, barley and rye, can damage the lining of the small intestine and cause a complex host of symptoms, from abdominal pain and bloating to ulcers and anemia, which can make diagnosis difficult. The disease is now five times more common than it was 50 years ago, Dr Joseph A Murray, a gastroenterologist at the Mayo Clinic, told the New York Times two years ago.  The new report suggested that decreased gluten consumption could be causing a “plateau” of celiac disease. It did not examine the reasons behind the gluten-free eating, but Kim said he believes the uptick may stem from wider availability and reduced prices of gluten-free products, the diet becoming “trendy” for health-conscious people and “self-diagnosed gluten-sensitivity” by those hoping to alleviate gastrointestinal symptoms. “Young females especially, they are a group that is affected by commercials and social media,” he said. He intends to do a follow-up study to look at the characteristics of those with a gluten-free diet.  In an article published with the study titled Maybe It’s Not the Gluten, Dr Daphne Miller of the University of California, San Francisco, who was not involved in Kim’s study, said it was “important that this choice [to go gluten-free] not be dismissed as an unfounded trend except for those with celiac disease”. Researchers should use this study as an opportunity to try to understand how factors associated with a gluten-free diet might “affect a variety of symptoms, including gastrointestinal function, cognition, and overall wellbeing”, she said.  Miller wrote that removing foods that contain gluten from the diet also removes fermentable oligosaccharides, disaccharides, monosaccharides and polyols – better known as FODMAPs – from the diet, something that may alleviate gastrointestinal symptoms similar to those suffered by celiacs.  Miller noted a 2013 Australian study that found a low FODMAPs diet effectively reduced such symptoms, and there were no negative effects when gluten was reintroduced.  Kelly Courson, a gluten-free lifestyle expert and consultant who has celiac disease, said doctors were often reluctant to diagnose non-celiac patients who “knew that gluten made them sick” with another condition such as non-celiac gluten sensitivity.  She said she did not preach that no one should eat gluten, but some might be surprised by the results if they try to cut it out. “Who am I to say they [shouldn’t] stick to a gluten-free diet because they just feel better or lighter or less bloated?” Courson said. “It might be nothing life threatening, but if their overall quality of life improves or just the side benefits of just feeling bloated after eating pasta.”  But blogger and author Erica Dermer, who has celiac disease with severe symptoms, said that when those anxious about gluten approached her for advice, she warned them against self-diagnosis of celiac disease, as adopting a gluten-free diet could possibly hide other medical problems. “Before you get my recipe for chocolate cupcakes, you’re going to tell me if you got tested for celiac or not,” she said.  Some seem to believe eating gluten-free is a weight loss tool, though Dermer pointed out gluten-free foods may be more highly caloric and less healthy than a normal diet.  Courson said the idea that gluten-free food is inherently healthy frustrated her. “When somebody in that trend category is eating gluten-free cookies and sugary junk foods thinking that it’s healthy – that’s a waste of money and it’s going to bounce back on them with weight gain,” Courson said. “Then they’re going to tell people, I tried gluten-free and it didn’t work for me.”  “If you don’t have celiac disease, then these diets are not going to help you,” Dr Peter HR Green, the director of the celiac disease center at the Columbia University’s medical school told the New Yorker in 2014.  Kim, who has an interest in gastroenterology, said the inspiration for his research emerged from seeing a growing selection of gluten-free products available in grocery stores and chain restaurants. A 2015 Gallup poll found that about one in five Americans include gluten-free foods in their diet, while one third of adults surveyed by Consumer Reports in 2014 said they were trying to cut gluten. Actor Gwyneth Paltrow, who does not have celiac disease, has been known to support the diet as well as numerous athletes and celebrities.
Percentage of the population avoiding gluten but not having disorder more than tripled between 2009 and 2014, possibly due to diet trends and marketing