Hashimoto's, Thyroid, and Celiac Disease: Is There a Link?
The issue of gluten in food has become a hot health topic. Gluten is a protein found in wheat, wheat-related products like spelt, kamut, farro, durum, bulgur, semolina, and other grains including barley and rye. You can find a comprehensive list at the Celiac Disease Foundation’s "Sources of Gluten" page.
There are two health issues that arise out of gluten exposure: nonceliac wheat sensitivity, and celiac disease. In both conditions, exposure to gluten causes digestive issues, inflammation, and a variety of other symptoms. In celiac disease, however, the intestinal lining can be destroyed by regular exposure to gluten, leading to even more serious health complications.
Symptoms of nonceliac wheat sensitivity and celiac disease
Some of the common symptoms of nonceliac wheat sensitivity and celiac disease include:
Osteoporosis or bone loss
Missed menstrual periods
Canker sores inside your mouth
Joint pain and muscle aches
Peripheral neuropathy (tingling, numbness or pain in your hands and feet)
Erratic menstrual periods
Dermatitis herpetiformis, an itchy rash
Hives and rashes
In children, nonceliac wheat sensitivity and celiac disease can also show up as irritability, behavioral problems, Attention Deficit Hyperactivity Disorder (ADHD), failure to thrive, and delayed growth and puberty.
Diagnosis of nonceliac wheat sensitivity and celiac disease
To make a diagnosis, you need to be consuming foods with gluten, and have blood tests that include:
IgA and IgG gliadin antibodies
IgA transglutaminase antibodies (TGA)
IgA endomysium antibodies (EMA)
If any of these tests show elevated antibodies, a biopsy should also be performed to confirm the diagnosis of celiac disease.
In some cases, one or more of these antibody tests may be positive, without confirmation of celiac disease. This is the scenario when nonceliac wheat sensitivity is diagnosed.
Even if your antibody tests are negative, if you have symptoms triggered by gluten exposure — and an elimination diet to remove gluten is followed by an improvement in those symptoms — you can be diagnosed with nonceliac wheat sensitivity.
According to the Beyond Celiac advocacy group, there are 18 million Americans with nonceliac wheat sensitivity, six times the 2 million Americans who have celiac disease.
Experts who use more controversial stool analysis tests estimate that as many as 35 percent of Americans — more than 114 million people — are sensitive to gluten.
Treatment of nonceliac wheat sensitivity and celiac disease
There is a treatment for nonceliac wheat sensitivity and celiac disease: strictly following a 100 percent gluten-free diet for life. This helps prevent any destruction of the intestinal lining and prevents most complications.
A gluten-free diet means that you do not eat wheat or wheat products, rye, and barley, and you avoid processed foods that contain any gluten or have been contaminated by exposure or proximity to gluten. The Celiac Disease Foundation has an excellent overview of what you can and can’t eat when following a gluten-free diet.
The link to thyroid disease
There are well-established links connecting nonceliac wheat sensitivity, celiac disease, gluten, and thyroid disease.
Specifically, we know that having nonceliac wheat sensitivity or celiac disease significantly increases your risk of having (or developing) thyroid disease, especially autoimmune thyroid disease.
A 2014 Italian study found, for example, that among patients with nonceliac wheat sensitivity, 29 percent developed autoimmune thyroid disease, mainly Hashimoto's thyroiditis. Among patients with celiac disease, 29 percent developed autoimmune thyroid disease, mainly Hashimoto's thyroiditis.
Also, having a thyroid condition — especially autoimmune Hashimoto’s thyroiditis — significantly increases your risk of having nonceliac wheat sensitivity or celiac disease.
One study found that more than 4 percent of patients with autoimmune thyroid disease test positive for celiac disease, compared to less than 1 percent testing positive in the population that does not have autoimmune thyroid disease.
There are several theories that could explain these links:
Celiac disease causes malabsorption of key nutrients such as iodine and selenium that increase the risk of developing a thyroid condition.
Celiac disease may be an autoimmune disease.
Patients with activated immune systems in celiac disease are at greater risk of developing autoimmune diseases, including autoimmune thyroid problems.
Of particular interest is the fact that the molecular structure of the protein in gluten is also very similar to your thyroid. In some cases, your immune system reacts to — and attacks — both. If you have autoimmune Hashimoto’s thyroiditis and you eat gluten, your immune system may mistakenly mount an attack on your thyroid, and the attack can last for months.
What should you do?
If you have been formally diagnosed with celiac disease or nonceliac wheat sensitivity, you absolutely need to follow a strict, 100 percent gluten-free diet and lifestyle. Groups like the Celiac Disease Foundation are a great starting point for advice on how to follow a gluten-free diet and avoid gluten exposure.
If you have celiac disease or nonceliac wheat sensitivity, you should be periodically screened for thyroid disease, including thyroid stimulating hormone (TSH), free T4, free T3, and thyroid peroxidase (TPO) antibody tests.
If you have a thyroid condition, you should be routinely screened for celiac disease, given the increased coexistence of these two health disorders.
If you have Hashimoto’s thyroiditis, consider following a gluten-free diet. A 2017 study evaluating the impact of nutrition on Hashimoto's thyroiditis concluded that if you have Hashimoto's thyroiditis — whether or not you test positive for celiac disease — you will benefit from a gluten-free diet in terms of disease complication, disease progression, and your symptoms.
While it’s more controversial, some health experts feel that if you are hypothyroid — whether or not it is caused by Hashimoto’s — you should follow a gluten-free diet. One study, for example, found improvement of hypothyroidism symptoms, and a reduction of the dosage of thyroid hormone replacement medication in hypothyroid patients who followed a gluten-free diet.