Could your fatigue, headaches, digestive problems, depression, or aches and pains be gluten sensitivity symptoms, even if you don’t actually have celiac disease or a wheat allergy? More and more research is pointing to gluten sensitivity as a possible cause of a variety of symptoms. One of the largest studies to-date on non-celiac gluten sensitivity, involving almost 500 patients, identified all these symptoms and more as common in people with this form of gluten intolerance.[1]

What is non-celiac gluten sensitivity?

Non-celiac gluten sensitivity occurs when ingestion of wheat and other gluten-containing grains causes symptoms, but the patient does not have celiac disease or wheat allergy. Slightly more than 1% of the general population is now believed to have non-celiac gluten sensitivity, but estimates of its prevalence range from 0.6% up to 6%.[1] In comparison, 1% of the population has celiac disease.

The study followed 486 patients from 38 Italian centers with expertise in gluten-related disorders. All patients were diagnosed with non-celiac gluten sensitivity.[1] All of the patients reported having intestinal and non-intestinal symptoms occurring after the ingestion of gluten, which improved or disappeared when gluten was withdrawn from the diet, and recurred when gluten was reintroduced into the diet. Furthermore, all the patients tested negative for celiac disease and wheat allergy. (They had negative celiac tests for anti-tissue transglutaminase antibodies and anti-endomysial antibodies, and negative allergy tests for specific IgE antibodies to wheat.)

Common symptoms of gluten sensitivity

Non-celiac gluten sensitivity symptoms identified in the study include a combination of irritable bowel syndrome-like symptoms and body-wide symptoms. The time lapse between gluten ingestion and the appearance of symptoms varied from a few hours to a day in the large majority of patients. The most commonly reported symptoms of gluten sensitivity were:

• Abdominal pain
• Bloating
• Bowel habit abnormalities (either diarrhea or constipation)
• Nausea
• Epigastric (upper abdominal) pain
• Gastroesophageal reflux
• Tiredness
• Headache
• Fibromyalgia-like joint/muscle pain
• Leg or arm numbness
• ‘Foggy mind’
• Dermatitis or skin rash
• Depression
• Anxiety
• Canker sores
• Anemia (both iron and folate deficiency anemia)

Other health conditions associated with gluten sensitivity

Almost half (47%) of the patients in the study had also been diagnosed with irritable bowel syndrome, 35% had other food intolerances (such as lactose intolerance), and 22% had immediate-type (IgE) allergies to foods or environmental allergens. Autoimmune diseases were detected in 14% of patients.

No good lab tests available for identifying gluten sensitivity

The patients underwent blood testing to see if they had any positive biomarkers linked to gluten intolerance. The most frequent laboratory finding was the presence of IgG anti-gliadin antibodies in 25% of the patients. These antibodies against gluten are not found exclusively in people with non-celiac gluten sensitivity. They are also found in celiac disease, some autoimmune liver disorders and connective tissue diseases, some people with irritable bowel syndrome, and even in some healthy controls. However, their finding in patients with symptoms of gluten sensitivity can help support the diagnosis.

Some of the patients also tested positive for the genetic markers linked to celiac disease (HLA-DQ2/-DQ8), but the researchers found no correlation between testing positive for the genetic markers and non-celiac gluten sensitivity. Some of the patients also had intestinal biopsies; for those that did, the biopsies were normal in 69% and 31% showed signs of mild injury to the intestinal lining.

Interestingly, more than 20% of patients showed signs of malabsorption with lab testing, with low levels of iron (ferritin), folic acid, or vitamin D. The researchers speculated that these deficiencies might be due to inflammation of the small intestine caused by the gluten sensitivity.

Gluten sensitivity symptoms in children

One of the only studies so far to document non-celiac gluten sensitivity symptoms in children was recently published in the Journal of Pediatrics.[2] Abdominal pain was the most frequently reported symptom after a gluten challenge, reported in 80% children, followed by diarrhea (73%), fatigue (33%), and bloating (26%). Limb pain, vomiting, constipation, headache, and failure to thrive were also reported.

One of the interesting findings in this study was the length of time it took for symptoms to occur after the children ingested gluten. The average time was 44 hours, with a range of 38 to 80 hours. This means that a child’s gluten-related symptoms are not likely to appear for two days after eating gluten and symptoms may not occur until four days have passed. In contrast, symptoms in most adults seem to appear within a day.

What to do if you suspect gluten sensitivity

If you think you might have a gluten sensitivity, most experts recommend you visit a healthcare provider with experience in diagnosing celiac disease and other gluten intolerances before you try a gluten elimination diet on your own. This is because it is important to rule out celiac disease, and some of the important tests for celiac disease will not work if you have already eliminated gluten from your diet. For suggestions on how to find a health care provider experienced in nutritional medicine, use the NHAI Doctor Search Directory and select nutrition from the “additional practice specialty” drop down box. A provider skilled in gluten intolerances will also be able to help guide you through a proper gluten elimination and challenge diet, helping make sure you completely eliminate all hidden sources of gluten.

[1] BMC Med. 2014 May 23;12:85.

[2] J Pediatr. 2014;164(3):463–467.