When you first begin researching gluten intolerance or a gluten-free diet, you may find yourself puzzled by all the different terminology used to refer to the gluten phenomenon. Some of these terms are used because there are different conditions relating to problems digesting gluten or just wheat, but some of these terms are not technically accurate.

For example, here’s a quick list of terms that might fall under the umbrella term of gluten intolerance:

• Celiac Disease (or Coeliac Disease)
• Celiac Sprue Disease
• Endemic Sprue
• Gluten Allergy
• Gluten Enteropathy
• Gluten Intolerance
• Gluten Sensitivity
• Gluten-Sensitive Enteropathy
• Non-Celiac Gluten Sensitivity (NCGS)
• Non-Tropical Sprue
• Wheat Allergy
• Wheat Intolerance

Many — but not all — of these terms are synonyms. Some of them are not technical terms at all but are casually used by laymen. So in total we have a confusing mess of semantics within the gluten intolerance discussion.

Yet all these terms can be boiled down to three fundamental conditions, all which I put under the umbrella term gluten intolerance.

Celiac Disease

Celiac disease is an autoimmune disease where the primary target of the immune system is the small intestine. Celiac disease is the formal disease at the center of gluten intolerance. There are specific biomarkers for identifying and diagnosing celiac disease.

It occurs in genetically-predisposed individuals and it is triggered by the consumption of gluten, a protein composite unique to specific grassy grains or cereal grains, particularly wheat. The gluten issue alone can be confusing, as gluten is neither a grain nor a protein, despite how many people refer to it as such. See my guide: What Is Gluten?

The word celiac comes from the Greek word for abdominal, koiliakós. The more close translation is coeliac with an o, but in the United States most doctors and researchers spell it celiac.

Celiac disease is also known as celiac sprue disease, gluten enteropathy (which basically means “disease of the small intestine caused by gluten”), gluten-sensitive enteropathy, non-tropical sprue, and endemic sprue. If you see any of those terms, including variations with celiac spelled coeliac, they all refer to the same condition, celiac disease. For more celiac disease and celiac disease symptoms, see my comprehensive guide: Celiac Disease Symptoms

Non-Celiac Gluten Sensitivity

This condition is trickier, because it was only formally recognized in early 2011, even though many doctors and researchers believed it existed because of personal experience and anecdotal evidence. It is altogether possible that yet another term will be conceived for this new disease.

In the simplest terms, a Non-Celiac Gluten Sensitivity is present when an individual experiences an adverse reaction to consuming gluten but multiple tests are negative for either celiac disease or a wheat allergy. You will also see it listed as Non-Celiac Gluten Sensitive or by its somewhat common abbreviation NCGS.

In a study entitled “Divergence of gut permeability and mucosal immune gene expression in two gluten-associated conditions: celiac disease and gluten sensitivity,” published in the journal BMC Medicine in March of 2011, researchers determined that there is a gluten sensitivity that manifests itself differently than celiac disease. This study revealed that it is not just a degree of celiac disease but rather an entirely new and different disease that results from consuming gluten.

Its symptoms are similar (though usually not as severe) to the symptoms of celiac disease, but biopsies of the small intestine indicate a fundamentally different change to the mucosal lining than when celiac disease is present.

Wheat Allergy

A wheat allergy is not an autoimmune disease like celiac disease. It is a Type 1 Hypersensitivity, which means it is an allergic reaction similar to what occurs in hay fever or with a peanut allergy. A wheat allergy will trigger a more immediate response to consuming wheat than what many gluten sensitivity or celiac disease patients will endure. A wheat allergy is not a form of celiac disease or gluten sensitivity; it is different condition altogether.

The term wheat intolerance is not particularly meaningful. It is either a layman’s term for gluten intolerance or wheat allergy or it is used to imply a mild wheat allergy, but it is not a technically accurate term in its own right.

For more on the wheat allergy phenomenon, read my guide to Wheat Allergy Symptoms or to better understand its difference from celiac disease read either my Gluten Intolerance lesson or my lesson on Gluten Allergy Symptoms.

While those are the three conditions under the umbrella of the term gluten intolerance, there is still one term left to discuss.

Gluten Allergy

One of the most common terms used to refer to either celiac disease or a gluten sensitivity is gluten allergy. Unfortunately, this term has no technical meaning and can be misleading. Celiac disease and gluten sensitivity are not allergies; an allergy is a Type 1 Hypersensitivity, whereas both celiac disease and non-celiac gluten sensitivity are autoimmune responses, not allergic responses.

And a wheat allergy is an allergic response specifically to wheat, and not to other gluten-containing grains, so using gluten allergy for wheat allergy is not accurate either.

The only way I can see the term as being useful is as a casual way to communicate your condition to people who do not need to know the details of your life but must understand that you can’t have gluten. For example, maybe a waiter at a restaurant. The term celiac disease sounds cryptic while the terms gluten intolerance or gluten sensitivity may inaccurately connote or imply a less severe response to a food. Many people are familiar with how severe a peanut allergy can be or with the seriousness of anaphylactic shock, so if you just say gluten allergy, people may quickly get the point you need to communicate.

Arguing with it being accurate or not at that point may just be pedantic; using the term gluten allergy in this way is just a pragmatic way to get the point across quickly in a casual, social environment.

However, online I too often see the terms used interchangeably even in a formal context, which is neither accurate nor helpful to people trying to understand these serious and complex conditions.

This entire discussion got longer than I’d hoped, but as you can see, the three different conditions underneath the gluten intolerance umbrella and the dozen or so different terms used to refer to those three different conditions can make this entire discussion a semantic mess. I hope those of you who took the time to read this entire clarification better understand all the different gluten intolerance vocabulary used in this field of medical research.