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Celiac disease is more common in people with Hashimoto's thyroiditis than in the general population, so a celiac blood test is reasonable if you have Hashimoto's, especially if you also have gut symptoms or anemia. If you have both conditions, a gluten-free diet is essential treatment for the celiac disease.
If you have Hashimoto's without celiac disease, the evidence that going gluten-free helps your thyroid is limited. A few small studies suggest a modest effect on thyroid antibodies and hormone levels, but researchers say it is not yet enough to recommend the diet to everyone with Hashimoto's.
Key takeaways
- Roughly 1 in 62 people with autoimmune thyroid disease also has biopsy-confirmed celiac disease, a higher rate than in the general population.
- Screening for celiac disease uses the same tTG-IgA and total IgA blood test as for anyone else, done while eating gluten.
- A pooled analysis of four small studies hinted at lower thyroid antibodies on a gluten-free diet but fell short of firm proof.
- Thyroid medicine and regular monitoring remain the core of Hashimoto's care, whatever you decide about gluten.
What Hashimoto's thyroiditis is
Hashimoto's thyroiditis is an autoimmune condition in which the immune system gradually damages the thyroid gland. It is the most common cause of an underactive thyroid (hypothyroidism), which affects about 5 in 100 Americans.1 It is 4 to 10 times more common in women than in men.1
Doctors confirm it with blood tests for thyroid hormone levels (TSH and free T4) and thyroid antibodies, mainly thyroid peroxidase (TPO) antibodies. Some people have positive antibodies while their hormone levels are still in the normal range. You can read how the clinic approaches thyroid care on its thyroid page.
Why celiac disease and thyroid disease travel together
Autoimmune conditions tend to cluster, and having one raises the chance of another. People are more likely to develop Hashimoto's disease if they have other autoimmune disorders, including celiac disease, lupus and rheumatoid arthritis.1
A meta-analysis of more than 6,000 people with autoimmune thyroid disease found biopsy-confirmed celiac disease in 1.6% overall, about 1 in 62.2 The rate was 2.7% in adults in the studies that looked at adults alone. For comparison, a global analysis put biopsy-confirmed celiac disease at about 0.7% of the general population.3
You may have read that gluten "looks like" thyroid tissue, so the immune system attacks both. This idea, called molecular mimicry, is a hypothesis. It has not been established as a cause of Hashimoto's.
Should you be screened for celiac disease?
The authors of the thyroid meta-analysis argued that people with autoimmune thyroid disease should be screened for celiac disease, given the higher rate. It is especially worth asking about if you have:
- Bloating, diarrhea, weight loss or other gut symptoms
- Iron-deficiency anemia or low vitamin levels without a clear reason
- Mouth ulcers, joint pain or an itchy, blistering rash
- A close relative with celiac disease or another autoimmune condition
The test is the standard one: tTG-IgA with a total IgA level, while you are still eating gluten. A positive result leads to a gastroenterologist and, in most adults, an endoscopy with small-bowel biopsies to confirm the diagnosis.4 Your primary care doctor or endocrinologist in Pennsylvania can usually order the blood test.
What the evidence says about gluten-free diets for Hashimoto's
Many people with Hashimoto's try a gluten-free diet on their own, hoping to calm the autoimmune process. A 2023 meta-analysis looked for studies of this in people with Hashimoto's who did not have celiac disease. It found only four studies, with 87 patients in total, following the diet for about six months on average.
The pooled results showed a small drop in TSH and a small rise in free T4, and a trend toward lower thyroid antibodies that did not reach statistical significance. The effect looked larger in people with other gluten-related conditions. The authors concluded that current evidence is not yet sufficient to recommend a gluten-free diet to all patients with Hashimoto's.5
That leaves room for a personal trial if you and your clinician agree, as long as you have had celiac testing first and the diet stays nutritionally balanced. It is not a replacement for thyroid hormone treatment when your levels call for it.
Your next step
If you have Hashimoto's and have never had a celiac blood test, that is the practical place to start. Our guide to celiac disease testing guidelines explains each step. If you are considering a broader wheat antibody panel, read what the Wheat Zoomer measures first, so you know which results are diagnostic and which are not. More articles are in our wheat and gluten testing guide.
Frequently asked questions
Will a gluten-free diet lower my TPO antibodies?
It might a little, based on small studies, but the evidence is not strong. Antibody levels also vary on their own, so a single change is hard to interpret.
If I have celiac disease and Hashimoto's, does treating celiac help my thyroid?
A strict gluten-free diet is the treatment for celiac disease and helps the gut heal. Your thyroid still needs its own monitoring and treatment.
Should my family be tested?
Guidelines recommend testing first-degree relatives of people with confirmed celiac disease.4 Ask your doctor about thyroid testing for relatives with symptoms.
Related reading
This article is for general education and is not medical advice. Decisions about testing and treatment should be made with your clinician. If you have severe symptoms, call 911. For a suspected poisoning, call Poison Control at 1-800-222-1222.
