Okay everyone, there is a lot of misinformation going around the net about the role of gluten in thyroid disease. In the next two blogs I'll try to suss out everything we thyroid patients need to know about the role of gluten in our diets.
I've been researching gluten-related disorders and thyroid disease since my diagnosis of celiac disease on May 1, 2002. Later that year I was also diagnosed with Graves' disease.
I have some background on this issue since I have published several articles for the highly regarded "Journal of Gluten Sensitivity" and was lucky to speak on behalf of celiac patients at the National Institutes of Health Consensus Conference on Celiac Disease. As far as I can ascertain, these are the facts as we now know them.
Thyroid disease is three times as common in celiac patients as it is in the general population, and Hashimoto's disease is three time as common in celiac disease patients. That comes to about 2.5% of Hashimoto's patients who have celiac disease. Still a very low number, but high enough to suggest that autoimmune thyroid patients should all be screened for celiac disease. A reference at the bottom of this page applies to this topic. You may want to print it out for your doctor.
Those who are being treated with thyroid drugs while being diagnosed with celiac disease will need less and less medication as the lining of the small intestine heals on the gluten-free diet. All autoimmune thyroid patients who are diagnosed with celiac disease should be closely monitored and tested regularly to adjust for better absorption of thyroid medication and to see whether their autoimmune status is improved on the gluten free diet.
This is another of the many reasons that celiac disease should be properly ruled out by antibody screening lab tests before a gluten-free diet is instituted. Going off gluten will render these tests void since you have to be actively eating gluten on a regular basis in order to produce the antibodies for celiac disease. Please note, that this only applies to celiac patients and not to people with non-celiac gluten sensitivity or wheat allergy. Those last two groups have not proven to have a higher likelihood of autoimmune thyroid disease than does anyone in the general population. But please, those who are on the gluten-free diet and have noted a positive change in their health should by no means go off it. Non-celiac gluten sensitivity is real and should not be taken lightly.
Those who have already made the plunge into the gluten-free lifestyle would have to go back on gluten in order to test positive for celiac disease. You can find more on that later in this blog.
“... a gluten-free trial of up to 6 weeks is the only way to determine if you have non-celiac gluten sensitivity”
Gluten-related disorders (the official umbrella term) are comprised of three distinct conditions. They are:
Celiac disease (CD), is an IgA-mediated immune response (that is, an autoimmune disease). A patient must be genetically susceptible with either the HLA DQ8 or the HLA DQ2 haplotype in order to develop CD, although most people with these genes do not go on to develop celiac disease. Those who have both haplotypes have a 25% liklihood of developing CD.
Non-celiac gluten sensitivity (NCGS), which appears to be a dysfunction of the innate immune system. It’s cause and mechanism are not well-understood. There are no lab tests for it as yet.
Wheat allergy, an IgE-mediated immune response
The popular, yet misused term “gluten allergy,” is not medically defined and isn’t used in a well-informed discussion of these topics. Although people can be allergic to any of the gluten grains (wheat, rye and/or barley), there are no tests for an allergy to gluten itself, defined as a protein fragment common to all three of these grains. While, strictly speaking, all grains, including corn, millet, etc., have their own kinds of gluten, they are not harmful in the same way. For the sake of this discussion, "gluten" will only refer to the kind that comes from wheat, rye and barley.
As to non-celiac gluten sensitivity (NCGS), it's distinctly different from either celiac disease or wheat allergy and occurs in the general population at a rate anywhere between five and twenty percent depending on whose clinical opinion or which very small study you reference. Without conclusive biomarkers to NCGS it's difficult to put an exact number on the prevalence since so much of it is self-reported. That means there could be many more who haven't taken the difficult step of eliminating gluten from their diets in order to see if it helps their symptoms. It could also mean that the placebo effect or other changes in their diet may account for their improvement. To further cloud the issue, we can't discount the possibility that other things in the forbidden grains besides gluten account for the improvement (see low FODMAPS diet).
We have no reason, as yet, to suspect that it's more common in thyroid patients. Some research has not shown a greater association between NCGS in people with autoimmune disease than in non-autoimmune patients. Other research shows a slightly higher likelihood of some autoimmune diseases in folks who have NCGS suggesting a connection.
No study has been done that shows a slightly greater occurrence of intestinal permeability in people with NCGS, so we don't yet understand why there are some people with NCGS who have more autoimmune disease. It's too early to say that NCGS causes autommunity, or whether autommune patients are more susceptible to NCGS for other reasons.
It is, however, recommended by the National Institutes of Health that everyone with an autoimmune disease be screened for celiac disease with the EMA and tTG antibody tests. A total IgA test is also needed to assess the accuracy of the first two. If either of these tests show positive results, an endoscopy with biopsies will likely be called for.
So far, a gluten-free trial of up to 6 weeks is the only way to determine if you have non-celiac gluten sensitivity. Unlike celiac disease, there are no objective tests yet available for NCGS, but it’s important to note that there are highly-regarded researchers in the field of gastroenterology who are looking for objective biomarkers. It has been said by the pioneering and well-regarded celiac disease researcher Dr. Alessio Fasano that we are at the same point in our medical understanding about NCGS that we were with celiac disease 30 years ago.
It is strongly advised that before doing a gluten-free trial, that anyone who suspects they have a reaction from eating gluten be tested for celiac disease. Celiac disease antibody tests will not be accurate unless the patient is actively consuming the equivalent of two slices of wheat-based bread daily for at least six consecutive weeks. The importance of determining whether you have this inherited autoimmune disease, from a perspective of family responsibility, is obvious. A child, parent or sibling of a celiac patient has a one in 20 chance of also having the condition, so they should all be screened in the advent of a celiac diagnosis. Since a significant percentage of celiac patients have absolutely no symptoms of the disease, screening of first-degree relatives is extremely important.
NCGS appears to cause widespread inflammation; its symptom profile is extensive and covers many body systems. Even if it's just a one-out-of-twenty (5%) chance that you have non-celiac gluten sensitivity, it can make a difference in your inflammation profile. Five percent likelihood is still high enough to suggest that people who suffer with autoimmune disease give that option careful consideration if going off gluten can reduce their general inflammation.
To make matters more confusing, symptoms of NCGS are quite similar to those of celiac disease. Digestive dysfunction such as bloating, irritable bowel, diarrhea, constipation, gas and abdominal pain are classic complaints, but both disorders also cause joint and muscle pain, headaches, limb numbness, skin rashes, fatigue, cognitive abnormalities (like brain fog) and sleep disturbances. Psychiatric complaints such as anxiety, depression, and personality disruption have been noted.
Edit - July 14, 2014 In vitro studies have shown that exposure to wheat in non-celiac patients triggers the production of zonulin. Zonulin is known to cause the intestinal permeability (leaky gut) that is thought to trigger a cascade of events in celiac patients that can lead to many other autoimmune diseases. However, in non-celiacs, far less zonulin is released and it only effects the first layer of the intestinal barrier and does not result in the kind of intestinal permeability that is known to affect celiac patients.
Schizophrenic and autism patients are also being seriously investigated because of studies that have shown that each group has a subset that seems to respond to the gluten free diet.
In our next blog, we will discuss whether or not non-celiac gluten sensitivity affects those with autoimmune disease and whether everyone with autoimmune disease really needs to avoid gluten.
Author's Note (7-14-2014): After doing more research, I've edited this article and amended my statement that non-celiac gluten sensitivity does not correlate with higher incidence of autoimmune disease. Although there is a study that shows no higher occurrence of autoimmune disease in people with NCGS, I've also read a different study that shows a slightly raised incidence of certain autoimmune conditions in people who have NCGS. Whether NCGS causes the higher rate of autoimmune disease or there is another factor that causes both is not yet determined. We do know that there is no higher rate of intestinal permeability in those patients who have non-celiac gluten intolerance, however.
Prevalence of thyroid disorders in untreated adult celiac disease patients and effect of gluten withdrawal: an Italian multicenter study: The American Journal of Gastroenterology (2001) 96, 751–757; doi:10.1111/j.1572-0241.2001.03617.x.
Non-Celiac Gluten Sensitivity: The New Frontier of Gluten Related Disorders: Oct 2013; 5(10): 3839–3853. Published online Sep 26, 2013. doi: 10.3390/nu5103839. PMCID: PMC3820047
Differentiating between celiac disease and NCGS: http://www.ncbi.nlm.nih.gov/pubmed/24619056
Effect of treated celiac disease on levothyroxine dosage: DOI: 10.1016/j.amjmed.2011.09.003
Screening for celiac disease in autoimmune patients: Clin Med Res. Oct 2007; 5(3): 184–192. doi: 10.3121/cmr.2007.738. PMCID: PMC2111403
Celiac Disease and Autoimmune Thyroid Disease
This subject has raised some controversy, to help clear up the confusion, I'm listing more citations below:
Edit: July 14, 2014 - New citations
The 2004 NIH Consensus Conference on Celiac Disease
Archives of Internal Medicine; 2003 Feb 10;163(3):286-92. Prevalence of celiac disease in at-risk and not-at-risk groups in the United States: a large multicenter study.
Gastrointestinal-associated autoantibodies in different autoimmune diseases. Am J Clin Exp Immunol. 2012 May 25;1(1):49-55. Print 2012. http://www.ncbi.nlm.nih.gov/pubmed/23885314
Non-celiac Gluten Sensitivity Does Not Cause Intestinal Permeability.
Imran Aziz and David S. Sanders (2012). Emerging concepts: from coeliac disease to non-coeliac gluten sensitivity. Proceedings of the Nutrition Society, 71, pp 576-580. doi:10.1017/S002966511200081X.
Is there higher prevalence of some AI diseases in patients with NCGS? Non-celiac gluten sensitivity.
Gastroenterol Hepatol Bed Bench. 2013 Summer; 6(3): 115–119. PMCID: PMC4017515
Biological markers that indicate a difference between celiac disease and non-celiac gluten sensitivity:
Non coeliac gluten sensitivity. Gastroenterol Hepatol Bed Bech. 2013 Summer; 6(3): 115-119