In our multi-part Q&A series on gluten sensitivity, we go straight to the experts.
[Updated May 21, 2015]
People with non-celiac gluten sensitivity—gluten sensitivity, for short—feel better when they don’t eat gluten. They’re less fatigued or bloated or have less joint pain. Maybe their mood is better. But gluten sensitivity is frequently self-diagnosed. And a recent study found just a quarter of self-diagnosed adults actually fulfilled the criteria for a gluten sensitivity diagnosis—testing for celiac (and wheat allergy) before going gluten-free and noting that symptoms improve on the gluten-free diet. Many of the study participants didn’t test for celiac disease before cutting out the gluten.
Q: We often hear people say that they’ve been tested for gluten sensitivity. There are saliva and stool tests out there that claim to diagnose the condition. Some physicians espouse these tests. Why aren’t these tests considered viable by celiac experts?
Alessio Fasano, MD: There isn’t a validated test for gluten sensitivity yet. We’re not being conservative or skeptical. There are rules for any given test. You have to find the test, validate it and have it approved by the FDA so that you can use it. If insurance doesn’t cover the test, generally, it’s not FDA approved.
Stefano Guandalini, MD: Research has yet to detect any biomarkers for this condition. It is not a matter of refusing to accept this or that test: the point here is that no consistent change has been found in patients with gluten sensitivity that can be relied upon to be used as a diagnostic tool. Hence, any claim to have found such a test is, to this day, completely devoid of any scientific support.
Daniel Leffler, MD: It would be a huge step forward for us to have a reliable and accurate biomarker for gluten sensitivity. Not only could we better determine who would benefit from gluten avoidance, a biomarker would help us better understand the condition and define the patient population. But there’s been no convincing evidence that any of the tests out there are useful. None of them are FDA approved because they don’t meet minimum standards for showing a medical test is valid. And some haven’t been tested at all.
Cynthia Rudert, MD: You have to be careful when people say they’ve been tested for gluten sensitivity because there is no FDA-approved test. I don’t use stool or salivary testing. None of the celiac centers use these tests. Right now, gluten sensitivity is a diagnosis of exclusion—you rule out all other possibilities like celiac disease and wheat allergy before considering gluten sensitivity.
Q: How close are we to having a broadly accepted test?
Fasano: Two years ago, we began a double-blind, placebo-controlled trial—the only way to make sure we identify the true gluten-sensitive people—and we’re close to finishing this trial. Next year, we’ll “break the blind” and see what the data tells us.
Guandalini: I don’t have a crystal ball to answer this! But in my humble opinion, we are quite a distance away because, again in my opinion, non-celiac gluten sensitivity is an umbrella term, encompassing several different conditions. As such, I see it as unlikely that we will find a single test that would cover all of these disorders.
Leffler: It’s hard to know. Lots of people are working on this. A breakthrough could be right around the corner or years and years away. It goes back to what’s causing gluten sensitivity. If gluten sensitivity is more like irritable bowel syndrome,* a test may not be right around the corner. But if gluten sensitivity is closer to celiac disease, we could postulate that we should be able to find, test and validate a biomarker in the near future.
Rudert: I’m not aware of anything on the horizon.
Q: Most people who try the gluten-free diet do so without getting screened for celiac disease first. Why is that a problem?
Fasano: Once you go on the gluten-free diet, the tools to determine which part of the spectrum of gluten-related disorders you’re on are gone. We have tests for celiac disease and wheat allergy but they’re useless if you’re already on a gluten-free diet. People argue, “If the treatment is the same—the gluten-free diet—does it really matter what the reason is?” And yes, the treatment is the same—the gluten-free diet. But if you have celiac disease, the consequences of not strictly following the gluten-free diet matter tremendously.
Guandalini: We need to educate everybody—if you feel that gluten doesn’t agree with you, don’t jump into the diet before ruling out celiac. The test for celiac disease is a simple blood test that takes one minute to perform. Results are available in a few days. Once the increased celiac-specific antibodies in the blood and the inflammation in the small intestine are gone as a result of the gluten-free diet, there is no chance to make a diagnosis of celiac disease. You need to know you don’t have celiac disease because celiac disease is a chronic, incurable condition and treatment (the gluten-free diet) needs to be strict and for life.
Leffler: Although treatment is similar for celiac disease and gluten sensitivity, many people with gluten sensitivity don’t need to be as strict about avoiding gluten. And they aren’t necessarily going to react to the non-wheat grains, barley and rye. Furthermore, people with celiac disease are at risk for bone density issues and other autoimmune disorders in a way that those with gluten sensitivity don’t appear to be. Knowing if you have celiac disease versus gluten sensitivity is important in determining how best to monitor your condition. For example, how strict do you need to be in terms of eating gluten-free? How do you manage family members and their risk of developing celiac? Do you have your kids tested?
Rudert: This happens all too often. Patients will say to me, “I looked on the Internet or talked to my doctor, best friend or neighbor who said I should go gluten free.” Six months later, feeling better, they ask me, “Do I have celiac disease?” At that point, it can be virtually impossible to ascertain. Serological tests will go back to normal after someone goes on the gluten-free diet. How long this takes varies. Do you then perform a gluten challenge? I’m not a fan of this because we don’t know how much gluten to give and for how long. Not to mention the fact that patients don’t like having to eat gluten again.
Q: If someone wants to find out if they have gluten sensitivity, how should they go about it?
Fasano: First, again, don’t go on the gluten-free diet. Second, if they believe gluten is a problem because they’ve seen a pattern or something, consult with a doctor who has knowledge on the matter. If no other diagnosis is identified and you’ve ruled out other forms of gluten reaction—celiac disease and wheat allergy—you can try the gluten-free diet. If symptoms get better, ideally, you’d do a double-blind gluten challenge to make sure the problem is gluten and not something else. [In a double-blind challenge, neither patient nor doctor knows if gluten or placebo pills are being given.]
Guandalini: First of all, be properly tested for celiac disease and wheat allergy. Once these conditions have been ruled out, then you may try the gluten-free diet.
Leffler: While most GI doctors are somewhat knowledgeable about celiac disease, awareness of gluten sensitivity is more sporadic. Patients need to be their own advocate. Tell your doctor you’d like to try the gluten-free diet but you know you’re supposed to get celiac testing done first. Follow up at a celiac center if you live in an area where there is one. If you’re planning to move forward with the gluten-free diet, finding a knowledgeable dietitian is a great next step. Dietitians specializing in gluten-related disorders can be found on the Academy of Nutrition and Dietetics website [eatright.org].
Rudert: Ideally, start with a celiac panel. Usually this is negative in people with gluten sensitivity. Every case is unique but it’s always important for your doctor to get a detailed medical history, since there’s no reliable test for gluten sensitivity to give you a definite answer. What are your symptoms? Could a medication be to blame? What’s the family history? Be sure your doctor is giving you enough time—and really listens.
Senior medical correspondent Christine Boyd lives in Baltimore, MD.
In Part 3 of our “Are You Gluten-Sensitive?” series, the experts discuss “outside-the-gut” symptoms, including ataxia (a balance problem) and migraines.