Celiac Disease and Thyroid Health
Published June 30 2014
Celiac disease is an autoimmune condition that is triggered by gluten. This condition affects both adults and children, and while people with this condition can experience gastrointestinal symptoms such as bloating, gas, stomach pain, diarrhea or constipation, it’s common for others to experience extraintestinal symptoms. Some of these signs and symptoms include dermatitis herpetiformis, anemia, osteoporosis, weight loss, female infertility, neurological problems, and other health issues. As I’ll discuss in this article, there is a higher prevalence of Celiac disease in autoimmune thyroid conditions.
Let’s begin by taking about why people develop Celiac disease. Just as is the case with most autoimmune conditions, Celiac disease is triggered by a combination of genetic and lifestyle factors. With regards to the genetics of Celiac Disease, more than 95% of patients with Celiac disease share the major histocompatibility complex II class human leukocyte antigen (HLA) DQ2 or DQ8 haplotype (1). As a result, if someone tests negative for these markers then there is a pretty good chance they don’t have Celiac disease, although not having these markers doesn’t completely rule this condition out, and of course there is the possibility that the person will have a non-autoimmune gluten sensitivity issue, which I’ll discuss later in this article.
Additional Testing For Celiac Disease
In addition to testing for the genetic markers of Celiac disease, one can also obtain a Celiac panel. Although a negative Celiac panel doesn’t always rule out Celiac Disease, obtain such a panel is usually a good place to start if someone suspects a gluten sensitivity issue. Some people get the gliadin antibodies tested, but keep in mind that it’s possible for these to be negative even if someone has Celiac Disease. If a problem with gluten is suspected you want to test the gliadin antibodies, the antibodies to tissue transglutaminase, and the anti-endomysial antibodies. It’s also a good idea to test both immunoglobulin A (IgA) and immunoglobulin G (IgG). The reason for this is because if one of these immunoglobulins happen to be depressed it can result in a false negative result.
The company Cyrex Labs has a comprehensive test for gluten called the Wheat/gluten proteome reactivity and autoimmunity panel. This measures one dozen of the markers associated with gluten, and tests the IgA and IgG for each one. Although it’s a great test, very rarely do I order it, as I usually just recommend for my patients to just avoid gluten. However, if someone really wants to know if they have an intolerance to gluten then this is a test to consider obtaining. This is a more comprehensive test than a Celiac panel, as in addition to measuring alpha gliadin antibodies it also measures additional antibodies against wheat proteins and peptides. In addition, whereas a Celiac panel will only measure transglutaminase-2 antibodies, the Cyrex Labs panel will also test for the antibodies against transglutaminase-3 and transglutaminase-6. This is important, as is it possible to test negative for the transglutaminase-2 antibodies, yet be positive for either the transglutaminase-3 or transglutaminase-6 antibodies.
If one of the antibodies come out positive then the doctor might want to perform a biopsy from the small intestine. The reason for this is because Celiac disease frequently shows damage to the villi of the small intestine. However, just because someone has a negative biopsy doesn’t conclude that they don’t have Celiac disease. If someone has Celiac disease yet has mild intestinal damage then it’s possible to have a negative biopsy. On the other hand, if a biopsy is performed and is positive, then a follow-up biopsy can be conducted at a later date to determine if the person responded well to a gluten free diet.
Since Celiac disease can affect the absorption of some of the nutrients and can cause anemia, some other tests are important to obtain if one tests positive for this condition. This includes a complete blood count, a complete metabolic profile, an iron panel, as well as checking the vitamin B12 and vitamin D levels. Bone density can also be affected, and so a bone density scan might be a good idea in some cases.
So What Exactly Is Celiac Disease?
I started out by mentioning that Celiac disease is an autoimmune condition that is triggered by gluten. But what actually happens from a physiological standpoint when someone has Celiac disease? In order to better understand the mechanisms behind Celiac disease, it’s probably a good idea to briefly define some of the common proteins and structures associated with this condition. I briefly mentioned gliadin earlier, as this is a protein of gluten. So when you measure the gliadin antibodies, these are the antibodies that your body produces against one of the gluten proteins. Earlier I mentioned how it’s possible for the gliadin antibodies to be negative, yet for someone to still have Celiac disease. The reverse is true as well, as it’s possible to have positive gliadin antibodies yet not have Celiac disease. I’ll elaborate on this shortly.
Transglutaminase is a calcium-dependent enzyme that forms a complex with ingested gliadin and causes specific deamidation of gliadin (2), which in simple terms means that it modifies the protein structure of gliadin. It’s a complex process, but what’s important to understand is that autoantibodies against transglutaminase confirms that someone has Celiac disease, and thus will need to avoid gluten. So if you solely have gliadin antibodies then this isn’t considered an autoimmune process, and the reason for this is because gliadin is a protein of gluten, and isn’t part of your body. On the other hand, transglutaminase is an enzyme produced by your body, and so when there are antibodies against transglutaminase then this confirms the presence of autoimmunity. What about endomysium antibodies? The endomysium wraps around the muscle fibers, and so if you have positive anti-endomysial antibodies then this also confirms that you have an autoimmune component.
So without making this too difficult to understand, what essentially happens in someone with Celiac Disease is that someone consumes gluten, and the HLA-DQ2 and HLA-DQ8 antigen presenting cells I mentioned earlier present the gluten peptides to the T cells of our immune system, which results in immune system activation. In a case of “mistaken identity” the body will begin to produce antibodies against tissue transglutaminase, and anti-endomysium antibodies might also be present. When tissue transglutaminase-2 antibodies are present this will result in damage to the cells of the small intestine, and can lead to digestive symptoms, malabsorption, anemia, and some of the other problems I previously discussed. On the other hand, tissue transglutaminase-3 antibodies primarily affect the epidermis (the skin), whereas tissue transglutaminase-6 while affect the tissues of the nervous system.
What Is Non-Autoimmune Gluten Sensitivity?
Non-autoimmune gluten sensitivity, also known as Non-Celiac gluten sensitivity, is defined as a condition in which symptoms are triggered by gluten ingestion, in the absence of Celiac-specific antibodies and of classical Celiac villous atrophy, with variable Human Leukocyte Antigen (HLA) status and variable presence of first generation anti-gliadin antibodies (3). And so what this is saying is that this condition doesn’t necessarily cause damage to the villi, and there are no autoantibodies to tissue transglutaminase or anti-endomysial antibodies. However, in some cases there are positive gliadin antibodies. And the genetic markers will also be positive in some people.
Many people with Non-Celiac gluten sensitivity will experience symptoms upon ingesting gluten. As I discussed in the beginning of this article, they might experience gastrointestinal symptoms, or they might experience extraintestinal symptoms, such as fatigue, brain fog, dermatitis, anemia, or muscle and joint pain. The pathophysiology of non-autoimmune gluten sensitivity is still controversial, and whereas an increase in intestinal permeability (a leaky gut) is common in people with Celiac disease who continue to consume gluten, it’s not known whether people who don’t have Celiac disease but are sensitive to gluten are at risk of developing a leaky gut.
Is Eating A Small Amount of Gluten Okay?
If someone has Celiac disease then without question they need to strictly avoid gluten. Eating even a small amount can cause the development of the autoantibodies I discussed before, which in turn will lead to inflammation. I realize it’s not easy to completely avoid gluten, and what makes it even more challenging is that there are many hidden sources of gluten. Speaking of which, if you haven’t done so already I’d recommend reading my blog post entitled “Are You Really Gluten Free?”
If someone has a non-autoimmune gluten sensitivity problem should they still be strict when it comes to avoiding gluten? Well, if anyone has any type of gluten sensitivity I think it’s important to strictly avoid gluten. However, while someone with Celiac disease needs to avoid gluten on a permanent basis, there still is controversy over whether someone with a non-autoimmune gluten sensitivity should avoid gluten for the rest of their life. Some healthcare professionals will recommend for people with any type of gluten sensitivity to avoid gluten on a permanent basis. I’m still not sure about this, as while I think that everyone should minimize their consumption of gluten, even if they’re not sensitive to it, I’m not sure if everyone who has a gluten intolerance but doesn’t have Celiac disease needs to completely avoid gluten on a permanent basis. For example, if someone has developed a gluten sensitivity due to a leaky gut, upon healing the gut there is a chance that they might be able to tolerate gluten. But of course keep in mind that there is no good reason for eating gluten, and so even if someone can tolerate gluten it still is a good idea to minimize one’s consumption of it.
Celiac Disease and Thyroid Autoimmunity
Without question there is a much higher prevalence of Celiac disease in people with autoimmune thyroid conditions. This is the case with both Hashimoto’s Thyroiditis and Graves’ Disease.
Celiac Disease and Hashimoto’s Thyroiditis. One study involved 150 newly diagnosed patients with autoimmune thyroid disease, and the data suggested a significantly higher prevalence of Celiac disease in patients with autoimmune thyroid disease, in particular with Hashimoto’s Thyroiditis (4). A small study involving 27 adults with newly diagnosed Celiac disease showed that they had an increased risk of thyroid autoimmune conditions (5). This study showed that a gluten-free diet didn’t prevent the progression of the autoimmune thyroid condition during a follow-up of one year. So while some people with autoimmune thyroid conditions report a decrease in thyroid antibodies when they stop consuming gluten, this definitely isn’t the case with everyone. Another small study showed that a significant proportion of patients with Hashimoto’s Thyroiditis present signs of “potential” Celiac disease and of activated mucosal T cell immunity (6). Since Celiac disease seems to be more common in patients with hypothyroidism, a study looked to determine whether the absorption of levothyroxine was influenced by the presence of Celiac disease (7). The study showed that levothyroxine malabsorption likely occurs with hypothyroidism and untreated Celiac disease, and that absorption may improve after Celiac disease treatment. This is of course very important, as if someone with hypothyroidism is taking thyroid hormone and it doesn’t seem like it’s working well, it’s possible that they are having absorption problems which is responsible for this.
Celiac disease and Graves’ Disease. One study looked to determine the prevalence of Celiac disease in people with Graves’ Disease. This involved 111 patients, and the study showed that the prevalence of Celiac disease in patients with Graves’ hyperthyroidism was 4.5% as compared with 0.9% in healthy controls (8). Another study involving 161 patients looked to screen for Celiac disease in patients with Graves’ Disease, and confirmed that patients with Graves’ disease are at a substantial risk of Celiac disease (9).
Celiac Disease and Thyroid Autoimmunity in Children. Many children also have Celiac disease, and a few studies have shown a higher prevalence of thyroid autoimmunity in children with this condition (10) (11). This is very important, as if you have a child with Celiac disease, even if they aren’t experiencing any thyroid symptoms it probably would be a good idea to screen them for the presence of thyroid antibodies, especially anti-thyroglobulin antibodies and anti-thyroid peroxidase antibodies.
Steps To Take After Being Diagnosed With Celiac Disease
If someone has been diagnosed with Celiac disease then they want to take the following steps:
1. Avoid gluten…permanently. If someone has Celiac disease, eating even a small amount of gluten can result in the production of the autoantibodies mentioned earlier. As a result, if you have been diagnosed with Celiac disease you really do need to avoid eating gluten on a permanent basis.
2. Consider avoiding other foods which cross react with gluten. This isn’t always necessary, although one does need to consider that eating other foods such as corn can cause problems in people with Celiac disease. Research has shown that the proteins from corn can cause a Celiac-like immune response due to similar or alternative pathogenic mechanisms to the proteins found in wheat (12). In other words, eating corn can cause a similar response as gluten. So if someone with Celiac disease completely eliminates gluten from their diet but still has overt symptoms, then they might be reacting to corn, or a different type of food.
3. Conduct tests for anemia, nutrient deficiencies, and bone density. Because Celiac disease results in malabsorption of many nutrients it is a good idea to do some additional testing. For example, everyone with Celiac disease should receive a CBC and an iron panel. Serum testing for vitamin B12, folate, vitamin D, and magnesium also would be a good idea. Although the blood isn’t the best method of evaluating mild to moderate deficiencies of many nutrients, if someone has a severe nutrient deficiency this usually will show up on serum testing. Regardless of what the testing shows, everyone with Celiac disease should be on a good quality multivitamin with minerals. Due the malabsorption of nutrients people with Celiac disease might also have a decrease in bone density. As a result, in some cases having a bone density scan would be a good idea.
4. Test for a leaky gut. If someone has Celiac disease then I would recommend either doing a test for intestinal permeability (a leaky gut), or just assuming that someone has a leaky gut and then doing things to help them repair the gut. Many people with Celiac disease who stop eating gluten don’t take measures to help repair the gut.
5. Eat whole, healthy foods. This might seem obvious, but it is possible to be gluten free but still eat an unhealthy diet. And this what many people with Celiac disease do, as they avoid gluten, but eat a lot of “gluten free processed foods”. This includes gluten free cookies, gluten free cakes, gluten free potato chips, gluten free cereal, gluten free pasta, gluten free pizza, etc. I’m not saying that you can never eat these foods, but you of course want to eat mostly whole foods, and minimize the consumption of processed foods, even if they are gluten free.
There’s a lot more information relating to Celiac disease that I didn’t cover in this article. For example, there does seem to be a correlation between Celiac disease and irritable bowel syndrome (IBS). Other conditions such as autism and schizophrenia might also be related to gluten ingestion. If you visit pubmed.gov and do some research you will see that there is a correlation between Celiac disease and many chronic health conditions. And when this is the case, eliminating gluten usually will result in a dramatic improvement in the person’s health.
In summary, many people have Celiac disease, which is an autoimmune condition that is triggered by gluten. Celiac disease is more common in people with Graves’ Disease and Hashimoto’s Thyroiditis. Although a Celiac panel doesn’t always rule out Celiac disease, if someone is consuming gluten then it’s usually a good place to start. If someone has Celiac disease then they will need to avoid gluten on a permanent basis. They also will want to consider doing testing for anemia, nutrient deficiencies, and perhaps a bone density scan. Having a leaky gut is common for those people with Celiac disease, and so this is also something to consider. Finally, in addition to avoiding gluten, you ideally want to eat mostly whole, healthy foods, and minimize the consumption of processed gluten free foods.