Jen Smith, a 32-year-old graphic designer in Minneapolis, had expressed concerns to her primary-care doctor for years about digestive troubles, skin problems, and headaches. Although tests always came back normal, her symptoms persisted. “You’re fine,” Smith recalls the doctor saying. “Here’s Imitrex for your migraines.” Eventually, at the advice of a holistic health practitioner, Smith stopped eating gluten (a protein in wheat, barley, and rye) and joined a group that science is struggling to understand. She doesn’t have celiac disease, an autoimmune condition that attacks the intestines in response to gluten and affects about 1 percent of the population. But within weeks of eliminating bread, pasta, beer, and other gluten sources, she felt much better. That was a year ago. She still hasn’t told her doctor.
Nobody knows how many people, like Smith, claim gluten sensitivity, but it has become a frequent source of tension between sick patients and skeptical doctors largely because, so far, there is no way to confirm its existence. Celiac is fairly straightforward to diagnose with blood tests and biopsies (though most people who have it don’t realize it and, for reasons scientists can’t yet explain, it has become five times more common than a few decades ago). But tests that claim to verify gluten sensitivity have not been validated by independent research and remain controversial. And although people who have self-diagnosed feel certain that gluten is the source of their woes, there has been no official count of their numbers. “I don’t think gluten sensitivity is rare,” says Dr. Joseph Murray, a gastroenterologist at the Mayo Clinic. “But I can’t say it is common.”
Nevertheless, stories like Smith’s seem to be multiplying as the $10.5-billion gluten-free market expands at a rate that far outpaces the rising rate of celiac sufferers. One recent survey found that nearly 30 percent of adults are trying to cut down on or eliminate gluten.
Shunning gluten may help, Murray says, but not necessarily because of gluten. Instead, going gluten-free eliminates many heavy, starchy foods that often cause stomach upset. People may also eat less on a restrictive diet, at least at first, and that can make them feel better. “It could be they were eating too much to begin with,” he says.
But new research has linked gluten (and its avoidance) to the appearance as well as relief of digestive problems. In a study of 45 patients with irritable-bowel syndrome (IBS), Murray and colleagues reported last year that the group that was randomly assigned a gluten-free diet (but didn’t know it) experienced less diarrhea. Another study published in 2011 found that re-introducing gluten to people who had eliminated it caused a resurgence of the pain, bloating, and tiredness that come with IBS.
One theory is that gluten may cause inflammation in the bodies of people who are sensitive to it, leading to problems that can confound diagnosis. Kacey Morrow, a 34-year-old registered dietitian from Minneapolis, had long experienced chronic headaches, dizziness, digestive distress, partial seizures, frequent colds, and joint pain. The symptoms worsened with time and after she gave birth, even though she ate well and maintained a healthy weight. After consulting multiple specialists, she finally eliminated gluten. Within a couple months, her symptoms were gone. The change was so profound that she has focused her career on the link between nutrition and gut inflammation.
Morrow acknowledges that the scientific evidence on gluten is still emerging. “I probably would’ve continued to be skeptical if I hadn’t experienced such dramatic changes,” she says. But for her, the results have been “just undeniable.”