[Celiac Disease] About one in 133 Americans has celiac disease – an inherited, intestinal disorder in which the body cannot tolerate gluten, a protein found in wheat, rye and barley.^[4] Corn and rice products made in factories that also make wheat products can be contaminated with wheat gluten.^[5] When individuals with celiac disease ingest gluten, their immune system attacks and damages the lining of their small intestine causing malabsorption of nutrients from food. Long-term complications of untreated celiac disease include liver disease, intestinal cancer, and malnutrition that can lead to anemia, osteoporosis and miscarriage.^[4] A gluten-free diet is the only treatment for celiac disease.^[4]

[Wheat Allergy] Wheat allergy is another form of immune reaction against gluten and other wheat proteins. This disorder is characterized by an IgE mediated response resulting in respiratory symptoms or gastrointestinal symptoms.^[6]

[Non-Celiac Gluten Sensitivity [NCGS]] The majority of individuals seeking medical attention for gastrointestinal symptoms that benefit from gluten withdrawal, however, have non-celiac gluten sensitivity (NCGS).^[6] NCGS manifests as intestinal (diarrhea, abdominal discomfort or pain, bloating and flatulence) and/or extraintestinal symptoms (including fatigue, headache, lethargy) that occur after the ingestion of gluten and improve after gluten withdrawal.^[6] Symptoms of NCGS overlap with symptoms of the common disorder – irritable bowel syndrome. Whether it is the gluten or the grain that is responsible for these symptoms is unknown. Similarly, whether NCGS belongs to the spectrum of celiac disease with related immunology or to the spectrum of functional bowel disorders caused by other components of wheat is unknown.^[6]

[In addition to celiac disease,] investigators have identified that many other diseases, including irritable bowel syndrome, fibromyalgia, psoriasis, and many other autoimmune diseases, for example, have a high correlation with gliadin (gluten) sensitivity.

Keep in mind that when these people complaining of gluten sensitivity are tested, a large number of them are found to be nocebo responders. That means that when they are given a food that they think has gluten in it (when it doesn’t), they feel worse. And, when they are given real gluten they still feel poorly, as long as they know they are getting gluten. The internet is rife with unsubstantiated claims about gluten-free diets to make gluten the diet villain du jour. Claims like ‘17 million Americans are gluten sensitive,’ are not born by real studies.

Most people do not have gluten-sensitivity, nor do they need to eliminate wheat from their diets, however, non-celiac gluten sensitivity is not a clearly understood condition, and due to the wide variety of symptoms associated with this condition, many are not officially diagnosed, and others have an exaggerated emotional response promoted by all the hype against gluten, therefore the prevalence is not exactly known.

When is it Necessary to Go Gluten-Free?

For years, wheat has been blamed in diet books as a cause of obesity, dementia, and poor health. But there are only three health conditions that are gluten-related: wheat allergy, the autoimmune condition known as Celiac disease, and non-Celiac gluten sensitivity.

In Celiac disease, eating gluten provokes the body to launch an autoimmune attack on the small intestine.  This can lead to chronic inflammation and serious health problems throughout the body, not just in the digestive tract. Estimates are that about 1 percent of the population has Celiac disease .²  Another 1 percent of the population has a wheat allergy.

People with non-Celiac gluten sensitivity do not have the intestinal damage related to Celiac disease and they do not have an allergy to wheat or gluten. A diagnosis of gluten sensitivity is usually made after Celiac disease is ruled out and removing gluten from the diet removes the symptoms. Individuals with gluten sensitivity can have joint pain, muscle aches and fatigue in addition to digestive symptoms. The disease is not well understood and the symptoms are not clearly defined.

Overall, it is estimated that three to six percent of the population are sensitive to gluten.  This includes  irritable bowel syndrome and some autoimmune diseases that are sometimes  aggravated by gluten consumption.

A new category of problems classified as "wheat sensitivity" or "non-celiac gluten intolerance" has recently become widely recognized. This form of gluten intolerance is diagnosed when both celiac disease and wheat allergy have been excluded. Symptoms include abdominal discomfort, bloating, pain, and diarrhea. In addition, many people relate headaches, "foggy mind," depression, fatigue, muscle cramps, joint pain, numbness, and skin rash to wheat sensitivity. The actual incidence of non-celiac gluten intolerance is unknown. 

Because this condition is so non-specific, my guess is that most of these people are simply sick from their unhealthful diet of meat, dairy foods, vegetable oils, and other junk food. Blaming gluten or wheat is wrong, and as a result, their efforts on gluten-free eating are misplaced. Benefits seen while attempting any new more restrictive diet regimen are from simply removing foods recognized to be unhealthful, irrelevant to their containing gluten or not.