Medically reviewed by
Dr. Minako Abe, M.D., Board-certified emergency medicine physician researching the relationship between lifestyle and disease onset in relation to the immune system and cancer, Japan
In recent years, the gluten-free diet has exploded in popularity, and its adoption by people who do not require it medically has raised some concerns among some scientists and healthcare professionals. A survey by the market research group Circana (formerly known as the NPD Group) found that in 2013, nearly 30% of American adults claimed to be cutting down on gluten or going gluten-free.
According to researchers, this rise in popularity has been fueled in part by celebrity endorsements, diet trends, and self-diagnoses of gluten sensitivity. This has led to misconceptions about the diet’s health benefits and who should be following it. A 2013 study by Mintel (a market research company) also found that many Americans are drawn to gluten-free foods: about two-thirds (65%) believe they’re a healthier choice, while about a quarter (27%) specifically choose them to help with weight loss.
If you’ve been diagnosed with a thyroid disorder and want to know if you should also go gluten-free, then this is just the article for you. But, before we address all your concerns, let’s start with the basics. What exactly is gluten?
Gluten is a protein found in grains like wheat, barley, and rye. It gives dough its elasticity and helps it rise during baking. While gluten is harmless for most people, it can cause adverse reactions in individuals with certain conditions, such as celiac disease and non-celiac gluten sensitivity. A study published in 2019 in the American Journal of Gastroenterology found that even when following a gluten-free diet, approximately one-third of foods labeled gluten-free in restaurants still contain detectable levels of gluten. For those who really need to avoid gluten, this is alarming. But, it also highlights the need to be extra conscious and cautious of what you consume.
This article answers the following questions:
What is the difference between celiac disease and non-celiac gluten sensitivity?
Affecting about 1% of the global population, celiac disease is an autoimmune disorder triggered by the consumption of gluten in susceptible individuals. Gluten is a composite of two proteins glutenin and gliadin. Gliadin is the component of gluten that triggers this immune response. When someone with celiac disease consumes gluten, their immune system attacks the lining of the small intestine, leading to inflammation and intestinal permeability, commonly referred to as “leaky gut.”
Research suggests a strong link between celiac disease and autoimmune thyroid disorders, particularly Hashimoto’s thyroiditis. This is because people with celiac disease are more likely to have other autoimmune conditions due to shared genetic factors and immune system dysfunction. Here’s where the research gets even more interesting. Some studies suggest that a gluten-free diet might improve symptoms and autoantibody levels in people with Hashimoto’s, even if they don’t have celiac disease. However, the evidence is still not considered to be conclusive, as pointed out by a review of the scientific literature. In this review article, published in Nutrients in 2022, the authors recommended an anti-inflammatory diet instead of a gluten-free diet for Hashimoto’s.
Non-celiac gluten sensitivity (NCGS), on the other hand, is a condition characterized by adverse reactions to gluten in individuals who do not have celiac disease or a wheat allergy. While the exact mechanisms are not fully understood, NCGS shares symptoms with celiac disease, such as gastrointestinal discomfort, fatigue, and headaches. Some studies suggest a potential association between NCGS and thyroid disorders, including Hashimoto’s thyroiditis. In a study conducted across multiple medical centers in Italy, focusing on individuals who were thought to possibly have NCGS, Hashimoto’s thyroiditis was highly prevalent among the study participants with NCGS.
Is there a link between gluten and thyroid autoimmunity?
As discussed previously while looking at the difference between celiac disease and NCGS, there is indeed a connection between gluten and autoimmune thyroid disorders, particularly Hashimoto’s thyroiditis. Research shows that individuals with Hashimoto’s disease have a higher prevalence of gluten intolerance or celiac disease compared to the general population. Celiac disease has been found to impair the absorption of essential nutrients (including iodine), which are needed for thyroid hormone production. When it comes to Graves’ disease, the exact relationship between gluten and the disease is less understood.
Sensitivity to gluten causes changes in the intestine. In individuals with celiac disease, the intestinal permeability triggered by gliadin allows toxins and undigested food particles to pass through the gut lining into the bloodstream, where they may trigger immune responses and inflammation. Research has shown that a leaky gut can contribute to increased immune system activity associated with autoimmune thyroid diseases.
Autoantibodies are antibodies that target the body’s own tissues. The main defining feature of autoimmune diseases such as celiac disease, Hashimoto’s thyroiditis, and Graves’ disease is that the immune system mistakenly identifies specific proteins or cells within the body as foreign threats and produces autoantibodies to attack these “threats.”
Here are the antibodies involved in these diseases.
1. Celiac Disease
- Anti-tissue transglutaminase antibodies (tTG-IgA): These are the most commonly tested antibodies for celiac disease diagnosis. These antibodies target tissue transglutaminase, an enzyme involved in repairing body tissue.
- Anti-endomysial antibodies (EMA-IgA): These antibodies are highly specific for celiac disease and target the endomysium, a part of the connective tissue surrounding muscle fibers.
- Anti-deamidated gliadin peptide antibodies (DGP-IgA and DGP-IgG): These antibodies can be particularly useful in diagnosing cases where tTG-IgA might be unreliable, such as in children under 2 years old or individuals with IgA deficiency.
2. Hashimoto’s Thyroiditis
- Anti-thyroid peroxidase antibodies (TPO antibodies): These are the most commonly detected antibodies in Hashimoto’s thyroiditis and target an enzyme in the thyroid gland important for the production of thyroid hormones.
- Anti-thyroglobulin antibodies (Tg antibodies): These target thyroglobulin, which is a protein involved in the production of thyroid hormones in the thyroid gland.
3. Graves’ Disease
- Thyroid-stimulating hormone receptor antibodies (TRAb): These are antibodies that bind to the thyroid-stimulating hormone (TSH) receptors on thyroid cells. TRAbs can be either stimulating or blocking.
- Thyroid-stimulating Immunoglobulins (TSI): A subset of TRAb, these stimulate the thyroid to produce excessive amounts of hormones, causing hyperthyroidism.
These antibodies are essential in the diagnosis and management of these autoimmune diseases because their detection confirms the disease and guides treatment choices.
Do I really need a gluten-free diet?
The answer depends on your individual situation. If you have been diagnosed with celiac disease, then there’s really no other way around this; you have to eliminate gluten from your diet, regardless of whether you have a thyroid disorder or not. A gluten-free diet is also considered a necessity for people with NCGS.
Some studies have shown that a gluten-free diet may help people with certain conditions like irritable bowel syndrome (IBS), dermatitis herpetiformis, and diabetes. However, strictly sticking to this diet can lead to nutrient deficiencies and unhealthy eating patterns (including the likelihood of an excessive intake of fats and carbohydrates). To address this, researchers hope to make gluten-free foods to be more nutritious and appealing. Incorporating micronutrients and fiber that are often lacking in gluten-free foods seems to be an ideal approach. This way, people with these conditions can maintain a balanced and enjoyable diet.
If you’ve been diagnosed with an autoimmune thyroid disease (especially Hashimoto’s thyroiditis) and are considering a gluten-free diet, the general consensus among researchers is that unless you also have some form of gluten sensitivity, a gluten-free diet is not a necessity.
Interestingly, while thyroid hormone levels may not change, some individuals with Hashimoto’s disease report feeling better on a gluten-free diet, experiencing reduced fatigue, brain fog, and other symptoms that can overlap with both Hashimoto’s and gluten sensitivity conditions like Celiac disease. Researchers believe there are so many factors at play here and that the positive outcomes observed might be due to an improved gut health or a reduction in inflammation which can be a factor in both autoimmune thyroid disorders and gluten sensitivity.
It’s also worth mentioning that a gluten-free diet can be restrictive, expensive, and generally challenging to maintain. It’s therefore important to get guidance from a healthcare professional (a registered dietitian) before making any dietary changes. They can even guide you through a gluten-free trial if needed.
In any case, make sure you haven’t decided to go gluten-free solely for suspected thyroid issues without a confirmed diagnosis from a doctor.
If you have to maintain a gluten-free diet, always remember to:
- Read food labels carefully, especially those that don’t specifically have “gluten-free” indicated on them. This is very important because gluten can hide in various processed foods and condiments.
- Check the ingredients to confirm the absence of gluten in medications and supplements. Some medications and supplements may contain gluten as a binder or filler, but according to the FDA, this is rare. If there isn’t enough information on the label, you can check with the manufacturers or consult your pharmacist just to be sure. There are resources and databases that can also be of help.
Key takeaways
- The connection between gluten and thyroid function is complex and not fully understood.
- For individuals with celiac disease or NCGS, adopting a strict gluten-free diet is necessary to alleviate symptoms, promote healing of the intestine, and reduce the risk of associated complications, including autoimmune thyroid dysfunction.
- More research is needed to fully understand the mechanisms underlying the relationship between gluten and thyroid health.
- Currently, there’s no clear evidence that gluten directly affects thyroid function in people without celiac disease. However, some studies and anecdotal evidence suggest positive outcomes (improvements in symptoms) for certain individuals with Hashimoto’s after switching to a gluten-free diet.
- If you suspect gluten sensitivity and have thyroid problems, first discuss it with your doctor. Do not self-diagnose.
- It’s important to approach dietary changes with caution and under the guidance of a healthcare professional, especially if considering eliminating gluten from your diet. Doing this can help ensure you’re getting all the nutrients you need.
