By Kristin Ohlson, July/August 2009
Everyone at my book club peered at the fancy gluten-free cupcake someone had brought. It was for Anne, who recently had given up all forms of wheat, rye and barley because they contain gluten. (Gluten, as most bakers know, is the protein that gives dough its elastic quality.) I remember wondering why this slender, yoga-teaching, opera-singing woman was on this very restrictive diet—and whether I should try it too.
As the gluten-free bandwagon rolls along, it’s easy to feel like you’re missing something. Last year, Oprah Winfrey went on a 21-day cleanse that was free of gluten as well as caffeine, sugar, alcohol and animal products. Grains that are naturally gluten-free—such as quinoa, millet and teff—are becoming increasingly popular. And the rush of new gluten-free products into the marketplace is staggering: according to market research publisher Packaged Facts, 1,182 new gluten-free foods and beverages were introduced in 2008, continuing an average 33 percent annual increase since 2004. Books and websites claim that a gluten-free diet can help with weight loss, autism and dozens of other conditions.
Should we all be avoiding gluten? For most people, a gluten-free diet offers no benefits; in fact, it may even bring unwanted results, such as weight gain and nutritional deficiencies. Experts concur that gluten-free eating performs wonders for one group of people: those, like my friend Anne, who have celiac disease.
Moreover, the list of symptoms has ballooned. Celiac disease is now implicated in a huge list of symptoms beyond digestive problems, including arthritis, anemia, infertility, a rash on the elbows and knees often mistaken for psoriasis, improper formation of tooth enamel and osteoporosis.
To complicate matters further, some people with celiac disease are completely asymptomatic. Doctors who are savvy about risk factors spot the red flags in a patient’s medical history and recommend the proper screens: an initial blood test that detects the antibodies created when a person with celiac disease consumes gluten and then a biopsy of the small intestine to confirm damage to intestinal villi. Anyone with a relative who has celiac disease should be tested. So should people with other autoimmune diseases like type 1 diabetes or thyroid disease: having one autoimmune condition increases your risk for developing others. (My friend Anne, who had suffered gastrointestinal problems for years, was diagnosed shortly after discovering she had a thyroid disorder.)
But some doctors may miss the signs. That’s because even though celiac disease has been around for centuries—possibly since the domestication of wild grains 10,000 years ago—the medical establishment in the U.S. has lagged behind in its attention to the disease.
“The rate of celiac diagnosis depends on which country you live in,” says Peter Green, M.D., director of the Celiac Disease Center at Columbia University and author of Celiac Disease: A Hidden Epidemic. “It’s commonly recognized in the Scandinavian countries, Holland, Italy, Australia and Canada. In the United Kingdom, people diagnosed with the disease get gluten-free products from the national health plan as a pharmaceutical benefit. In Australia, there are gluten-free products on most menus. In Brazil, everything in a package is marked gluten-free or not. But in the United States, there wasn’t much interest in the disease for a long time, probably related to the fact that there was no pharmaceutical-industry involvement.”
Toward the end of World War II, the Netherlands suffered a “Winter of Starvation.” With shipments of staple foods, such as bread and cereal, disrupted, the Dutch ate tulip bulbs and whatever they could scavenge from the great outdoors. But while most people grew thinner under this harsh regimen, a pediatrician named Willem-Karel Dicke watched with interest as one group of his patients actually gained weight.
Eventually, Allied planes dropped bread to the hungry Dutch people. Most of the population began to regain the weight they had lost, but Dicke noticed that the children who had started thriving during the famine were sickly once again. These kids previously had been diagnosed with celiac disease, a condition marked by chronic intestinal troubles and malnutrition. Although celiac disease was named by a Greek physician in the first century B.C. (its name is derived from the Greek word for abdomen), the condition was still something of a medical mystery. Dicke and other experts had suspected that celiac symptoms stemmed from some sort of intolerance to wheat; the children’s dramatic health improvements during the time when grains were unavailable provided the proof. A few years later, Dicke and two colleagues published papers showing that it is specifically the gluten in wheat (and barley and rye) that causes people with celiac disease such distress. Today, experts concur that people with celiac disease carry at least two genes that predispose their small intestines to greet incoming gluten as an alien invader, not a nutrient.
“For celiacs, there’s a battle in your gut between your immune system and the gluten, which it considers an enemy,” says Joseph Murray, M.D., a gastroenterologist and professor of medicine at the Mayo Clinic in Minnesota. This immunological warfare winds up damaging the small, fingerlike projections called villi that line the gut. Under normal circumstances, the villi expand the surface area of the small intestine and allow it to absorb nutrients. But when doctors biopsy the small intestine of someone with celiac disease, they find that many of the villi have atrophied and flattened. The damage prevents proper absorption of nutrients, causes a variety of problems throughout the body and, left untreated, can even lead to cancers in the intestine.
When Dicke and his colleagues wrote their landmark paper, most people thought celiac disease affected only children—patients were often counseled that they would “grow out of it.” Now, it is widely recognized as an autoimmune disease that persists for a lifetime and can develop at any age. It sometimes becomes active after surgery, pregnancy, a viral infection or emotional stress, for reasons that remain unclear.
The last decade has seen a surge of interest in celiac disease. One boost came in 2002 from a five-year study of more than 13,000 people led by Alessio Fasano, M.D., medical director of the University of Maryland’s Center for Celiac Research. Prior to this research, it was assumed that celiac disease was very rare in the United States. However, Dr. Fasano’s study found a prevalence more consistent with the higher numbers in Europe, India and the rest of the Americas. Celiac disease was found in one out of every 68 adults with any celiac-related symptoms and in one of every 22 people who had first-degree relatives with the disorder. Of study participants not considered at-risk, one in 133 had the disease.
Two years later, the National Institutes of Health held a national conference on celiac disease. The resulting recommendations included increased education of medical professionals and the public about the disease and setting U.S. standards for labeling gluten-free foods. As a result, celiac diagnosis is increasing. Research suggests that it doubles every three years. (Gluten-free standards have been proposed, but the Food and Drug Administration has not yet finalized them.)
Experts estimate that as many as 3 million Americans (about 1 percent of the population) have celiac disease, but only 10 percent have been diagnosed. And like asthma and other autoimmune diseases, celiac seems to be on the rise. Research in the July 2009 issue of Gastroenterology underlines this increase. The study was based on blood samples taken from more than 9,000 Air Force recruits between 1948 and 1954. Led by the Mayo Clinic’s Joseph Murray, researchers tested the 50-year-old blood for antibodies generated by celiac disease. They found that 0.2 percent of the samples had them.
The researchers then drew blood from young men who were roughly the same age as the recruits had been when their blood was drawn and from older men who were born around the same time as the recruits. When they checked these new samples, 0.9 percent of the young men and 0.8 percent of the older men had the antibodies, suggesting that celiac disease may be four to four and a half times as common today as it was in the 1950s.
“It’s not just that we’re diagnosing celiac disease more,” Murray says. “There’s a lot more of it around. That tells us that something in our environment has dramatically changed the rate of celiac disease.” But experts don’t know what has changed. Some experts subscribe to the “hygiene theory,” which holds that our modern environment is so excessively sanitized that our immune systems don’t get a chance to develop properly during childhood. Others suspect that the prevalence of gluten in the modern diet is to blame.
Gluten’s ubiquitousness is precisely why celiac disease is difficult to manage. Breads, cakes, pastas and cereals may be the most obvious sources of gluten, but the protein also finds its way into many ingredients commonly used in processed foods as stabilizers, emulsifiers and thickeners. Canned soups and stews often contain modified wheat starch and so do some medications. Beer and whiskey are distilled from wheat and other grains. Some brands of vinegar, soy sauce and even salad dressings contain gluten, so it’s important to read ingredient lists closely. “Studies show that it only takes 50 milligrams of gluten [about 1⁄8 teaspoon of bread] to damage the villi, but many people get sick way before that,” says Cheryl Wilson, president of the Southern Arizona Celiac Support Group. “For instance, even the tiny crumbs that remain if I take croutons off a salad will make me sick.”
When people with celiac disease eliminate gluten entirely, they alleviate immediate symptoms (e.g., GI distress) and prevent damage to their small intestine—that’s absolutely clear. As to the other claims made for gluten-free diets, there is far less scientific consensus.Does a Gluten-Free Diet Help People with Austism Spectrum Disorder?
The publication of Karyn Seroussi’s Unraveling the Mystery of Autism and Pervasive Developmental Disorder: A Mother’s Story of Research and Recovery in 2000, and actress Jenny McCarthy’s books and activism, prompted many parents of autistic children to try a diet free of gluten and casein, a protein in milk. As some parents reported success with the diet, scientists devised studies to try to pin down the diet’s impact on behavior. So far, however, these studies haven’t convinced scientists of the diet’s effectiveness.
In the Cochrane Database of Systematic Reviews 2008, researchers reviewed studies that had been published on the effect of a gluten-free, casein-free diet on the behavior and cognitive and social functioning in people with autism. They only found two randomized, controlled trials (the gold standard of scientific research), both small, with a combined total of 35 participants. The review deemed the evidence inconclusive.
While only people with celiac disease react to gluten in ways that damage the body, others can have sensitivities to gluten or wheat allergies. These people may feel better avoiding gluten, especially if they’ve been getting it in fatty, sugary processed foods that offer little nutrition.
Can a Gluten-Free Diet Lead to Weight Loss? There’s no evidence that a gluten-free diet leads to weight loss—or even a plausible theory for why it would. In fact, moving from “regular” processed foods to gluten-free ones may result in weight gain. “Lots of gluten-free products are higher in fat,” says Tricia Thompson, M.S., R.D., author of The Gluten-Free Nutrition Guide. “Pretzels, for instance--manufacturers add fat to give them better mouthfeel.” (Plus, these pretzels cost four times as much as “regular” ones.)
Of all the misconceptions about gluten-free diets, the most dangerous is that you can self-diagnose celiac disease. If you go gluten-free, the antibodies that doctors screen for in the blood disappear. You may need to go back to eating gluten for several months to be properly tested.
“If [people] walk into their doctor’s office after being on a gluten-free diet, we can’t diagnose,” says Lori Mahajan, M.D., a pediatric gastroenterologist at the Cleveland Clinic. “If they’re off doing the diet on their own, they might not do it properly. They’ll keep increasing their risk of malignancy.”
So, if you think you might have celiac disease, schedule a visit with your doctor but keep eating bread and pasta until she tells you to stop. If you don’t have celiac disease, continue to enjoy your wheat, barley and rye—and maybe try a few of the lesser-known grains that people with celiac disease can enjoy. Many are great sources of fiber, protein and trace minerals. Teff, anyone?Kristin Ohlson writes about food, science and travel, among other things, from her home in Cleveland Heights, Ohio.