Who Really Needs to Be Gluten-Free?

By Dace L. Trence, MD, FACE

Are you avoiding gluten in your food and beverages? If so, have you noticed how much easier it is these days to find gluten-free selections in the grocery store and restaurants? Is it because celiac disease triggered by the ingestion of gluten is becoming a more common problem or because it is being recognized more frequently? Or is it an entirely different phenomenon?

Since EmPower Magazine last featured a celiac disease article several years ago, more has been learned about gluten-related disorders. Indeed, the prevalence of gluten-related conditions is on the rise, with increasing numbers of individuals trying out a gluten-free lifestyle to see if they feel better on the diet. And often they do. Yet when tested by their healthcare team, the results suggest that they do not have celiac disease. So what’s going on? Let’s examine the facts.

First described by British pediatrician Samuel Gee in 1887, celiac disease is a chronic autoimmune disease that causes inflammation in the small intestine triggered by dietary gluten, a family of proteins found in grains like wheat, barley, rye and triticale, a cross between wheat and rye. Derived from the Latin word that means glue, gluten is a substance that gives elasticity to dough, helping it to rise and keep its shape. It is found in many staple foods in the Western diet.

You must have specific genes that predispose you to possibly develop actual celiac disease. And although up to as many as 40 percent of the population has the specific genotype (HLADQ2 or HLA-DQ8) required for the development of celiac disease, only 2 percent to 3 percent of this population will subsequently develop the disease. The prevalence of celiac disease in the general population is 1 percent, with regional differences. For example, if you live in Algeria, the reported prevalence is 5.6 percent. If you live in Finland, it is 1 to 2.4 percent. If you live in the Netherlands, 0.5 percent.

Symptoms of the condition can be extremely variable. Gastrointestinal symptoms are more common in children. In those under the age of 3 years, diarrhea, loss of appetite, abdominal distention and poor growth should be reason to screen for celiac disease. Older children and adults may also report diarrhea and bloating, but may additionally experience constipation, abdominal pain, or weight loss. But not all symptoms relate to symptoms of the gut.

Poor growth, short stature, or delayed puberty may be the only symptoms of pediatric celiac disease. Also, tooth defects are common in very young children with celiac disease. Irondeficiency anemia is a very common presentation seen in as many as 32 percent of adults. In women with celiac disease, there is a reported increased risk of miscarriage. And there is an uncommon condition called dermatitis herpetiformis, which causes chronic, intensely itchy blistering of the skin, that can be a manifestation of gluten sensitivity, along with less-exotic dermatologic conditions such as hives, psoriasis and dry skin.

Even neurologic changes or psychiatric conditions can be a heralding sign of possible celiac disease. This may be linked to the inability to absorb adequate amounts of specific nutrients such as vitamin B12.

There are several serologic (blood) tests available to screen for celiac disease. Because the disease is characterized by elevated autoantibodies (an antibody produced by the immune system that is directed against one or more of the individual’s own proteins), specifically against transglutaminase 2 (TG2), endomysium, and/or deamidated gliadin peptide, blood testing can be done to check for the presence of these antibodies. Checking for the presence of transglutaminase immunoglobulin A (IgA) antibodies, or immunoglobulin G (IgG) antibodies in patients with immunoglobulin A deficiency, is considered the best screening test. If needed, an additional test can be performed to check for the presence of IgA endomysial antibodies, but experts advise this should be used only as a confirmatory test because of the cost and some challenges in interpreting test results. Before having these tests, it is important to continue eating a normal diet, including foods that contain gluten Otherwise, avoiding or eliminating gluten could cause the antibody levels to fall to normal, delaying a diagnosis.

A small intestine biopsy remains the gold standard for diagnosis and is recommended by the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition and the American College of Gastroenterology. The biopsy, in which multiple tissue samples typically are collected, should show characteristic intestinal wall and cell changes that are associated with celiac disease. Additional diagnostic procedures such as double-balloon enteroscopy, videocapsule endoscopy, or magnetic resonance imaging (MRI) are available but rarely used. They may have a role in very unusual situations, such as when there are discrepancies between blood testing and biopsy results, or when a patient with celiac disease has persistent or worsening symptoms despite following a gluten-free diet.

Because scientific evidence supports the premise that celiac disease is an autoimmune disease triggered when genetically predisposed individuals ingest gluten, the treatment is avoidance of gluten-containing products. At this time, a lifelong gluten-free diet is the only treatment option. This is easier to achieve than in the past due to better food labeling and availability of gluten-free products, but still can be a challenge as even trace amounts of gluten can be present in gluten-free foods…and these trace amounts can still trigger intestinal changes.

Experts also advise that a patient’s nutritional markers should be evaluated when celiac disease is diagnosed and, if abnormal, rechecked after one year of a gluten-free diet. This is because up to 28 percent of children with newly diagnosed celiac disease have a nutritional deficiency such as low iron, low folate, low vitamin B12, or low vitamin D, and adults with newly diagnosed celiac disease often have low folate, vitamin B12, zinc, or iron. Additionally, growth progress should be monitored in children with celiac disease.

Current clinical guidelines recommend follow-up blood testing of the antibodies and nutritional markers as a way to check for a patient’s dietary adherence, as truly sticking with a gluten-free diet will rapidly result in loss of the initial antibodies, and nutritional marker levels should return to normal. Other recommendations support a baseline bone density test for women and men older than 30 years diagnosed with celiac disease.

Beyond celiac disease, there is another condition related to gluten ingestion called non-celiac gluten sensitivity (NCGS). Characterized by a lack of tolerance to gluten-containing grains and symptoms similar to those seen in celiac disease, NCGS is often diagnosed when celiac disease and wheat allergy have been excluded.

Patients with NCGS lack the same antibodies and have the intestinal damage seen in celiac disease. Symptoms can include abdominal bloating, constipation and abdominal pain. Less likely but sometimes present are nausea, vomiting and weight loss. NCGS has had a curious symptom reported as “foggy brain,” described as slowed thinking, memory disturbance, or decreased sense of alertness. Headaches, joint and muscle pain, fatigue, depression, leg or arm numbness, dermatitis (eczema or skin rash), and anemia have also been reported.

Just how often NCGS is present is unclear as there is no way to specifically test for it, although it’s thought to be more common than celiac disease. Also unclear is why this condition develops, although some think the immune system is nvolved, just not due to a specific antibody response that indicates true celiac disease.

Until markers of NCGS can be identified, the diagnosis of NCGS — other than a subjective trial of a gluten-free diet and reported changes in how one feels — is limited to research settings. An example of such a clinical study — and obviously not easily performed in a normal clinic setting — is an individual diet challenge in which participants are given gluten (corresponding to approximately two slices of bread) or a placebo for one week, separated by a one-week “washout” period in which study subjects receive no treatment. Symptoms are carefully monitored throughout the challenge.

The good news is that NCGS may be transient. Experts recommend that a gluten-free diet be followed for 12 to 24 months, before testing with a gluten challenge. Currently there is no scientific evidence that a gluten-free diet is part of a healthier lifestyle. Gluten can be difficult to digest completely, even in the absence of sensitivity to the substance, so avoidance of gluten could make anyone feel better — less bloating, less bowel irregularity, and so forth. Gluten-containing cereals are a source of fermentable products that are poorly absorbed, so avoidance of these — especially by individuals with irritable bowel symptoms — can also be beneficial.

Finally, there is a third gluten-related disorder: wheat allergy. This is a true food allergy (an overreaction of the immune system to a specific food protein) and not to be confused with gluten intolerance or celiac disease. The body responds very quickly after a wheat product is ingested. Symptoms can include swelling or itching of the mouth, throat and skin; nasal congestion; watery eyes; and difficulty breathing. First identified during Roman Empire times and referred to as baker’s asthma, we now know this as an allergic response to inhaling wheat flours, which has been reported to affect up to 10 percent to 15 percent of all bakers, millers and pastry factory workers. Wheat allergy is more common in children, with a prevalence between 2 percent and 9 percent, and less so in adults, with a prevalence of 0.5 percent to 3 percent.

In summary, there are several gluten-related disorders. Fortunately, maintaining a gluten-free diet is becoming increasingly easier due to the increase in availability of gluten-free foods. If you are concerned that you might have a sensitivity to gluten, discuss screening with your healthcare team. This is especially important if there have been other family members already diagnosed with celiac disease, or if you have other autoimmune diseases such as type 1 diabetes mellitus or autoimmune liver disease.