Is gluten inflammatory? Sorting the wheat from the chaff of these claims

On Nutrition

Peruse almost any “anti-inflammatory” diet, and you’ll see gluten (or foods that contain it) on the “avoid” list? The idea that gluten is inflammatory is endorsed by many social media “wellness” influencers, celebrity doctors and health gurus. I’ve even had many clients tell me that one of their health care providers told them — almost offhandedly — to avoid gluten and dairy because they’re “inflammatory.”

As with many big nutrition myths, there’s often a small nugget of truth, and such is the case with gluten. Let’s dig in, starting with where you find gluten, and what “inflammation” means.

Gluten is a complex of proteins found in wheat, rye, barley and triticale (a cross between wheat and rye). This means it’s commonly found in bread — gluten is what gives bread dough its elasticity and structure, so it can rise and hold its shape — as well as pasta, cereal, pizza dough and many baked goods. The plant-based meat substitute seitan is made from gluten, and beers (unless labeled gluten-free) contain some gluten. Wheat flour or isolated gluten is also used as a binder or thickener in many foods, including sauces and soups, as well as in nonfood products such as Play-Doh and some cosmetic and bath products.

Inflammation is the immune system’s response to a physical or psychological irritant, whether it’s a burn, a cut, an injury, an infection or stress. When inflammation happens in response to a short-term problem, say, a paper cut or cold, it’s beneficial. When inflammation happens in response to ongoing stress or illness, physical inactivity, long-term exposure to harmful substances — pollutants, alcohol, drugs, tobacco — or certain food exposures (think peanuts in someone who has a peanut allergy), it can become chronic. This may increase the risk of some health conditions, including diabetes, cardiovascular disease and certain cancers.

Who needs to avoid gluten?

It is true that gluten is inflammatory for certain people. People with celiac disease have an abnormal immune system reaction when they eat gluten-containing foods, which can cause inflammation and damage in the intestinal tracts and other parts of the body. That damage can have a variety of negative health effects, including poor absorption of nutrients. Currently, a 100% gluten-free diet — which means no “cheat days” or making exceptions on vacations or during holidays — is the only way to prevent the inflammation, damage and symptoms.

Symptoms of celiac disease or non-celiac gluten sensitivity include diarrhea, abdominal pain or cramping, poor appetite, weight loss, bloating or feelings of early fullness, itchy rashes, and growth delay (in children). However, some people with celiac disease have no symptoms (“silent” celiac), and the first clue that something’s wrong may be signs of nutrient deficiency or malabsorption. An estimated 1-2% of the population may have celiac disease, which is diagnosed through blood tests that detect certain antibodies, administered while the person is still eating gluten, and often followed by an intestinal biopsy. Genetic tests can rule out celiac disease — if you don’t have a genetic predisposition, you can’t develop the disease.

People with wheat allergy must avoid all wheat-derived ingredients in food and nonfood products, which would include gluten from wheat, but not necessarily gluten from rye or barley. Wheat allergy, which may affect up to 1% of the population and is more common in children than in adults, can be diagnosed through skin testing.

People with non-celiac gluten/wheat sensitivity don’t have celiac disease or wheat allergy, yet they experience symptoms similar to those of celiac disease when they eat foods containing gluten. In some cases, they may be sensitive not to gluten, but to other proteins in wheat. Or, they may have irritable bowel syndrome, with symptoms triggered not by the gluten in wheat, rye and barley, but by the fructans, a type of fiber that in most people has health benefits, in those grains.

It’s estimated that 1-2% of people have non-celiac gluten/wheat sensitivity. There’s currently no validated test for this (IgG testing is not a valid test), so diagnosis is generally made after ruling out celiac disease and wheat allergy and assessing for IBS.

Tips for everyone else

Research suggests that more than 20% of the U.S. population follows a gluten-free diet or has done so in the past, even though the vast majority would not have a health-related reason to do so. In some ways, this is understandable. Because gluten is unhealthy for people with celiac disease, some people might avoid it just in case. People interested in anti-inflammatory diets may come across the false but compelling argument that because gluten triggers inflammation in people with celiac disease, avoiding it will prevent or reduce chronic inflammation in other people, too.

It’s especially easy to be seduced by anecdotal claims about gluten from testimonials (“Eliminating gluten improved my health, and it will improve yours, too”) or celebrity endorsements. And authors selling books calling gluten a “toxin” or the root of all diseases can be very persuasive, especially when they use scientific or medical language and cherry-picked “evidence.”

It’s a common belief that gluten-free foods are more healthful and nutritious than conventional foods, but that’s not necessarily true. Many naturally gluten-free foods — basically every whole food other than wheat, rye and barley — are nutritious, but processed gluten-free grain-based foods are much less likely to be fortified with folic acid, iron and other nutrients than regular foods containing gluten, which is a problem because nutrient fortification bridges important nutritional gaps for much of the population. Also, these gluten-free foods often contain less fiber and more sugar and fat than their wheat-, rye- or barley-based counterparts.

Plus, gluten-free processed foods tend to be more expensive than conventional foods. So unless you have celiac disease, wheat allergy, or non-celiac gluten/wheat sensitivity — or live and dine with people who do — don’t feel you should look for “gluten-free” on food labels.