Hypothyroidism and Gluten Don’t Mix
Eating gluten may drive autoimmune destruction of the thyroid gland.
The thyroid is the body’s master of metabolism, regulating important functions like digestion, energy production, mental sharpness, sweating, skin healing, fat burning, and heart rate.1
Unfortunately, a growing number of people have sluggish thyroid function, a condition known as hypothyroidism. Hypothyroidism can cause symptoms like:
• Brain fog
• Weight gain
• Dry skin and poor wound healing
• Feeling cold easily
• Hair loss
• Joint pain and poor recovery after working out
• Forgetfulness and brain fog
• Menstrual issues and fertility problems
• Nerve issues like carpal tunnel
• High cholesterol levels
• Fatty liver disease
If the thyroid gland itself starts to swell, hypothyroidism can also cause a sore throat, a sensation of something pressing on the front of the neck, a hoarse voice, or even a goiter (a visible swelling of the neck).2
Whereas iodine deficiency is to blame for most cases of hypothyroidism in developing nations,3 the most common cause of hypothyroidism in the developed world is Hashimoto’s thyroiditis (also called Hashimoto thyroiditis, Hashimoto’s, or Hashi’s, for short).4 Hashimoto’s is an autoimmune condition – the most common autoimmune disease, in fact – in which the body creates antibodies that attack and destroy the thyroid gland.5,6
Strategies to support people with Hashimoto’s should not only focus on supplementing with thyroid replacement hormone, but ideally also aim to balance the immune system and avoid things that trigger autoimmunity. One very simple way to do just that is to follow a gluten free diet.
Gluten fuels the attack on the thyroid.
Gluten is a protein found in certain grains, namely wheat, rye, barley, spelt, and contaminated oats. Gluten gives breads their elastic property, making them stretchy and chewy.7
Gluten is made up of different proteins, with gliadin and glutenin being the most potentially harmful for people with autoimmune diseases.7,8
After a gluten-containing food is eaten, the gliadin “escapes” through the gut lining (where it’s supposed to stay) and passes into the bloodstream (where it isn’t supposed to go). This escape is quite common in those with poor intestinal integrity (aka “leaky gut”). Folks with hypothyroidism (regardless of the cause) are highly likely to have a leaky gut, as thyroid hormone regulates digestion. Individuals with one or more autoimmune diseases are also likely to have leaky gut.9,10
Once the gliadin peptides cross into the bloodstream, the cells of the immune system recognize the gliadin as a foreign invader and respond by producing antibodies to attack the gliadin. This results in inflammation, which further damages the leaky gut and wreaks havoc in the body.11
Gliadin resembles the enzyme transglutaminase. Transglutaminase is found throughout the body, but in especially high concentrations in the thyroid. The antibodies designed to attack the gliadin peptides therefore mistakenly attack the thyroid, thus compromising its ability to make thyroid hormone.11 (This phenomenon of a foreign peptide resembling one found in the body is known as molecular mimicry.12)
In other words, every time somebody with Hashimoto’s eats gluten, their body responds by creating antibodies that injure the gut lining, create inflammation, and damage the thyroid.
Occasionally “cheating” on a gluten free diet can still cause harm.
Whenever a person with hypothyroidism eats gluten, their body begins attacking their thyroid – and that attack can last as long as six months!11
That’s why having a “cheat” on a gluten free diet even once in a while can still carry significant, negative consequences for a person with hypothyroidism. Reading labels (for foods as well as cosmetics and medications) is quite important to prevent accidental gluten exposure.
For example, I had a patient with Hashimoto’s who was very strict in following a gluten free diet – except for on Sundays at church, when he would take the Eucharist. He finally spoke with his priest about the matter, and the congregation started offering a gluten free Eucharist option for him. Within a few months, his carpal tunnel (nerve pain in the wrist and hand) was gone.
Is a gluten free diet still helpful if thyroid antibodies are normal?
The majority of cases of hypothyroidism in the developed world are caused by Hashimoto’s.13 Depending on the severity of the disease and/or the body’s ability to produce B cells (the cells that make antibodies), however, a person with Hashimoto’s may not always test positive on a blood test for thyroid antibodies.
Fortunately, the early implementation of a gluten free diet might be able to stave off thyroid gland destruction, preventing one’s condition from getting worse.14,15
The link between Hashimoto’s and celiac disease
Celiac disease is a serious genetic, autoimmune condition in which the ingestion of gluten causes significant damage to the small intestine.16
Studies have shown a strong connection between Hashimoto’s and celiac disease.17 That’s likely because autoimmunity begets autoimmunity: People with one autoimmune disease are at high risk of developing a second (or third).18,19
Gluten may be implicated not only in Hashimoto’s, but in a number of other autoimmune diseases like type 1 diabetes9,20,21 and psoriasis.19 In fact, one study reports that between 10 and 30% of patients with celiac disease test positive for thyroid and/or type 1 diabetes antibodies. The report also estimates that between 5 and 7% of patients with autoimmune thyroid disease, type 1 diabetes, and/or autoimmune diseases of more than one gland test positive for IgA tissue transglutaminase antibodies (an antibody seen in celiac disease). The authors explain that the early implementation of a gluten free diet may delay or even prevent the development of Hashimoto’s.14,15
Another study found that the incidence of celiac disease is 10- to 30-fold higher in those with autoimmune disease than in the general population.22
The rising rate of celiac disease is also likely to blame for the increase in Hashimoto’s and other autoimmune ailments. The incidence of celiac disease is estimated to have doubled in Finland between 1980 and 2000, and quadrupled in the United States between 1959 and 2009.23,24 It is therefore important that people with autoimmune diseases get tested for celiac disease, even if they have no noticeable digestive symptoms. (Note: celiac testing is only reliable if the patient is still eating gluten, so it’s best to get tested before adopting a gluten free diet.)
In a study exploring the occurrence of autoimmune thyroid disease, 79 celiacs (patients with celiac disease) were compared to 184 non-celiac control patients. Almost fourteen percent (13.9%) of the celiacs were found to have autoimmune thyroid disease, as compared to just 2.1% of the non-celiac controls. Sub-clinical (mild) thyroid disease was found in 10.1% of the celiac patients, in comparison to just 3.3% of the control patients. In short, patients with celiac disease were much more likely to have autoimmune thyroid disease.25
For those with celiac disease, going gluten free not only helps reel in thyroid health, but also reduces the risk of all cause mortality (death from other causes). In fact, undiagnosed celiac disease is associated with a nearly four-fold increased risk of death.23
What about people who don’t have celiac disease?
The importance of nutrition on thyroid health cannot be overstated – both for those with autoimmune and non-autoimmune thyroid disease, as well as for those with and without celiac disease.
While a gluten free diet is imperative for celiacs, a strong case for a gluten free diet among those with Hashimoto’s who do not have a diagnosis of celiac disease can still be made.26
A study performed in 62 Caucasian women investigated the potential role of a gluten free diet on thyroid lab tests. Half of the women (31 women) ate their usual diet inclusive of gluten; the other 31 women ate a gluten free diet. All women had blood tests performed at baseline and after three, six, and 12 months on the prescribed diet. Curiously, no significant difference in thyroid antibody counts were observed across the two groups, but the women who ate a gluten free diet had significant decreases in thyroid stimulating hormone (TSH) levels and increases in free T4 (thyroid hormone) levels – lab results associated with healthy, positive changes.27
Another study concludes: “Patients with hypothyroidism should often eliminate gluten from their diets, on account of potential interactions between gliadin and thyroid antigens.”28 After all, the molecular mimicry dynamic described in the second section of this article applies even to those who test negative for celiac disease.
Furthermore, there is strong evidence that autoimmune disorders like Hashimoto’s, dermatitis herpetiformis, psoriasis, and rheumatoid arthritis are associated with non-celiac gluten sensitivity (NCGS).29
In another study investigating the effects of a gluten free diet on thyroid autoimmunity, 34 women with Hashimoto’s were observed. Sixteen of the women followed a gluten free diet for six months; the other 18 women had no dietary restrictions. The blood tests of these women showed that those who followed an unrestricted diet had more or less the same thyroid and vitamin D lab values over time. The women who ate a gluten free diet, however, had lower TPO and TG thyroid antibody titers (suggestive of less autoimmune activity) and slightly higher vitamin D levels. The authors of the study conclude: “The obtained results suggest that the gluten-free diet may bring clinical benefits to women with autoimmune thyroid disease.”30
In short: gluten and thyroid health don’t mix
Eating a balanced gluten free diet may be an effective and drug-free method for both preventing and managing autoimmune hypothyroidism (Hashimoto’s). Before going gluten free, however, it’s important to first get checked for celiac disease.
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