How to Tell If You Have Non-Celiac Gluten Sensitivity

Carolyn Todd
Updated
You don't need to have celiac disease for gluten to cause you some seriously unpleasant symptoms. Here's what you should know about non-celiac gluten sensitivity and how to tell if you have it.

Not long ago, someone who insisted that eating gluten caused them unpleasant symptoms but tested negative for celiac disease (CD) might have elicited eye rolls. In years past, non-celiac gluten sensitivity (NCGS) wasn't taken very seriously, including by a wide swath of the medical community. This skepticism was based on a few things: There was (and still is) a lack of medical research on NCGS; it's hard to diagnose and the symptoms are very similar to those of CD and some other gastrointestinal (GI) tract disorders, like irritable bowel syndrome (IBS) and Crohn's disease.

As certified dietitian-nutritionist Gina Keatley explains to Allure, "With no physical or biochemical signs that gluten is causing the person's issues and very little rhyme or reason as to who is afflicted with this, it is really hard for outsiders to believe that it must be gluten." That said, in the last few years NCGS has become formally recognized as a distinct clinical condition.

Keri Gans, a registered dietitian-nutritionist and the author of The Small Change Diet, attributes this evolution in large part to grassroots patient advocacy: People are increasingly taking to the web to read up on gluten and share their experiences, then bringing their issues into the doctor's office. "The more people did that, the harder it was for the medical community to totally ignore what their patients are saying," Gans tells Allure. "More and more doctors started looking into it."

As Keatley points out, we don't have a good idea of how many people NCGS affects since it's not tracked like celiac is. "However, from anecdotal reports a significant portion of the population is impacted by this sensitivity," she says. Ahead, what you should know about NCGS and how to tell whether you might have it.

What is non-celiac gluten sensitivity?

NCGS is a clinical condition characterized by a gluten sensitivity that causes gastrointestinal and non-gastrointestinal symptoms similar to those of celiac disease, which improve when sufferers follow a gluten-free diet. "It's exactly what it sounds like," says Gans. "You're sensitive to gluten" — in other words, it makes you feel like crap — "but you test negative for celiac disease."

In addition to patient advocacy, recent research on NCGS has helped legitimize the condition from within medicine. In a study published in the British Medical Journal (BMJ) in 2016, Columbia University Medical Center researchers found evidence of both a systemic immune response and damage to the intestine lining in "a subset of individuals who experience sensitivity to wheat in the absence of celiac disease."

Not everybody who thinks they're gluten-sensitive is gluten-sensitive — people haphazardly use the term.

People with NCGS may still struggle to get their condition taken seriously, especially as eating gluten-free has become trendy among people whose bodies can handle gluten just fine. "Not everybody that thinks they're gluten-sensitive is gluten-sensitive," Gans says. "People haphazardly use the term. They blame every woe in their bodies on gluten when that's not necessarily the case — but that's not to dismiss those that are definitely sensitive to gluten."

How is NCGS different from celiac disease or a wheat allergy?

This is where confusion tends to arise. CD is an autoimmune disorder where the ingestion of even a very small amount of gluten triggers an inflammatory immune overreaction in the body that damages the lining of the small intestine, as the Mayo Clinic reports. This damage can lead to malabsorption of nutrients and a host of other complications, including anemia, fertility issues, and loss of bone density. We don't have evidence that NCGS, meanwhile, leads to lasting damage.

In a wheat allergy, the proteins in wheat other than gluten trigger a systemic immune reaction involving the production of antibodies. (This means that people with a wheat allergy can generally still eat barley and rye with no problem, according to Gans.) The symptoms usually show up within minutes or hours, according to the Mayo Clinic and can include GI issues. The more characteristic symptoms that differentiate a wheat allergy from CD and NCGS include swelling or itching of the mouth, throat, or nose; an itchy rash; hives; a headache; and trouble breathing. “There are some cases of wheat allergies so severe [they] can lead to anaphylactic shock and death,” Keatley says. (She adds that it is possible to have NCGS in addition to a wheat allergy.)

What causes NCGS and how many are affected?

More research is needed to figure out what leads to NCGS: It's unclear whether there is a genetic component or lifestyle or demographic risk factors. We're also not sure if it carries long-term complications or if it's linked to any other conditions. Until that 2016 study out of Columbia University suggested otherwise, the general belief was that NCGS did not trigger either an immunological response or intestinal damage. Still, the evidence is not definitive and as Keatley says, "NCGS is defined by its symptoms more than any measurable signs of disease."

How do you know if you have NCGS?

Diagnosing NCGS is not a straightforward process because as of yet there's no clinical test for it. "It's really based on you reporting your symptoms, discussing it with your doctor (a registered dietitian can also be a huge help here), ruling out CD, and then modifying your diet," Gans explains.

In most cases, according to Gans, "Gluten sensitivity is usually first discovered because somebody is complaining of all these GI problems." People may also experience vague, non-GI symptoms (as they also can with CD), including fatigue, joint and muscle pain, headaches, or a foggy mind. Sometimes a patient comes in thinking they have CD to discover that it's another GI issue, like IBS.

NCGS is defined by its symptoms more than any measurable signs of disease.

If you think you might have NCGS, your doctor's first step will likely be figuring out what's not going on. "First, you want to rule out celiac disease," Gans says. Your doctor can do blood work to screen for specific antibodies indicating an immune reaction to gluten (which means you have to be eating gluten for the test to work). The most definitive test, though, is a biopsy of the small intestine to check for damage on a cellular level. If both of those tests are negative, then you can rule out CD and move on. (Depending on your symptoms and medical history, the doctor may also want to test for a wheat allergy, although Gans says it's likely that if you have one, you've already figured that out.)

After these tests, Gans says she likes to take a look at a person's overall diet to make sure it's healthy and well-rounded. She recommends that patients try eliminating things like overly processed, packaged foods, excessive added sugar, heavily fried foods, and sometimes dairy so they can see how they feel. (Keatley notes that since elimination diets can be lengthy and tricky to navigate on your own, it's a good idea to work with a dietitian who can guide you.) Finally, "Once we've done that, if you're still not feeling better, we can try eliminating gluten,” Gans says. “And if you feel better once you've made that final step, then OK, we can say that you are intolerant to gluten.”

Gans adds that some people start to feel better on a gluten-free diet simply because they're more conscious of what they're eating in general, prioritizing nutrient-rich foods and cutting out the junk: "Some people maybe just need to look at their total diet and not demonize gluten for unnecessary reasons."

How do you treat NCGS?

The only tried-and-true treatment is the same as that for celiac disease: ditching gluten entirely. "If you decide that you're going to eliminate gluten, you've got to be committed to it 100 percent,” says Gans. "Not just a little, not when it's convenient, not just when you're at home." Even a little of the stuff could set off the unpleasant symptoms associated with NCGS.

This means cutting out more than just regular bread and pasta: You'll want to avoid any grains that contain gluten, including wheat, barley, rye, and triticale, a cross of wheat and rye. Scan the labels of any processed foods for added gluten as well as less obvious culprits derived from gluten-containing grains, such as brewer's yeast and malt vinegar. As Gans points out, you can find gluten in everything from salad dressing to certain lipsticks.

The safest and most nutritious staples for GF eaters are mostly whole, unprocessed foods, including beans, legumes, grain-like seeds like quinoa or millet, nuts, Greek yogurt, vegetables, and fruit. On the processed food side, the popularization of the GF diet in recent years means you can find substitutes for everything from bread and pasta to soy sauce and beer.

Finally, if you have NCGS and you do end up ingesting gluten, don't freak out, but don't throw your hands up and eat a doughnut, either: The more swiftly you move back toward a GF diet, the better you'll feel.

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