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Food Sensitivities & the Thyroid: Graves’ and Hashimoto’s

Naturopathic doctor Maura Scanlan explains how food sensitivities and allergies can contribute to autoimmune thyroid conditions such as Graves’ and Hashimoto’s.

Over the last few weeks we have been exploring the difference between food allergies and food sensitivities, and their symptoms. We have looked at the potential causes of food sensitivities and allergies and the impact they can have on your body. If you missed any of the previous articles, you can catch up by following the links below:

As we saw last time, food sensitivities cause inflammation that can occur anywhere in the body. In this article I want to explore how this inflammation affects the thyroid – a gland that is especially vulnerable to changes both inside and outside the body but first, let’s look at how the thyroid works and what happens when things go wrong.

What is the Thyroid and How Does it Work?

The thyroid gland is located in the center of the throat and is responsible for controlling our metabolism.  The thyroid gland is responsible for producing thyroid hormone which is made up of the amino acid tyrosine and the mineral iodine. The thyroid gland produces triiodothyronine (T3) and thyroxine (T4). T3 is the active form of thyroid hormone and is only produced in small amounts in the thyroid gland. The majority of T3 is converted from T4 (the inactive form) in the body’s cells. Production of these hormones is regulated by the production of Thyroid Stimulating Hormone (or TSH) in the pituitary gland in the brain.

Note: If you are prescribed medication to treat a thyroid problem, you may know T3 as the drug liothyronine or the brand name Cytomel and T4 as levothyroxine or Synthroid.

What Happens when Things Go Wrong?

When this regulation mechanism goes wrong it can result in either too much thyroid hormone being produced (hyperthyroid) or too little (hypothyroid). As a primary care physician, I work with many patients who have one or other of these conditions. Hypothyroid is more common than hyperthyroid and both occur more commonly in women than men, likely because of the relationship between female hormones and reproductive system and the thyroid gland.

There are a few different elements of thyroid hormone production that can go wrong.

  1. The thyroid gland itself has difficulty producing adequate amounts of T3 and T4 hormone.
  2. The pituitary gland does not produce the right amount of TSH thus affecting the how much thyroid hormone is produced.
  3. Cells located anywhere in the body do not have the ability to turn inactive T4 into active T3.

Today I am going to discuss the first of these – the problem with the thyroid gland itself producing thyroid hormone.

The most common cause of thyroid problems is autoimmune thyroid. What happens in autoimmune thyroid conditions is that the immune system produces antibodies that directly target the thyroid gland and damage it causing it to either produce too much thyroid hormone – what is known as autoimmune hyperthyroid or Graves’ disease  – or too little – autoimmune hypothyroid or Hashimoto’s disease.

There are two main autoimmune processes that damage the thyroid gland:

  1. Anti-thyroglobulin antibodies attack the protein thyroglobulin which is used by the thyroid gland to produce T4 and T3.
  2. Anti-thyroperoxidase antibodies (anti-TPO) affect the ability of iodide to convert into iodine which is needed to bind with tyrosine to create T3 and T4.

But what causes the immune system to go haywire and start attacking the thyroid gland? This is one of the most common questions I am asked.

The thyroid gland is a highly active gland that is very sensitive to both internal and external factors

One of the most dangerous external causes of thyroid damage is radiation. Radiation exposure can come from many different sources including medical or dental x-rays (which is why we wear lead barriers when we get an x-ray).  Another key source of radiation is a by-product of nuclear energy production. When a tsunami hit Japan in March 2011 damaging the Fukoshima nuclear power plant, the west coast of the United States was put on alert for radiation exposure drifting across the Pacific Ocean. Because of this possible radiation exposure, all babies born during the 6-month window following the Japanese tsunami will have a lifelong risk of increased thyroid conditions. I am the mother of one of these babies. Knowing this, my son will be periodically screened throughout his life to monitor for symptoms of hypo- or hyper-thyroid.

Other known causes of thyroid conditions are viruses and bacterial infections, environmental toxins (in addition to radiation), heavy metals and toxins. Genetics also play a role in who experiences symptoms of thyroid conditions. Commonly, multiple generations of a single family will have thyroid conditions.

People with thyroid and autoimmune diseases also tend to have increased symptoms with environmental allergens such as plant and tree pollen and grasses.

How Does Food Cause Thyroid Problems?

As we have discussed in previous articles, certain food can cause immune reactions and the formation of antigen antibody complexes – click here to read more about this. The thyroid gland is related to metabolism and is therefore susceptible to changes in the body. Increased inflammation from the production of inflammatory white blood cells can fuel thyroid auto-antibodies which attack the thyroid gland and cause the thyroid to become either over- or under-active.

There is a difference between a food sensitivity (IgG reaction), a food allergy (IgE reaction) and celiac disease in terms of what happens within the immune system. However, the end result can be the same – thyroid injury. In addition a link has been found between autoimmune thyroid conditions such as Graves’ and Hashimoto’s and the onset of celiac disease. It seems that when the immune system is programed for an “autoimmune reaction” this is not limited to the original organ, gland or tissue where it started. So, if the autoimmune disease originated in the digestive system, it can then move on to affect the thyroid gland as well, or vice versa.

Some foods act directly on the thyroid gland, making it harder for it to absorb the iodine it needs to function properly. These foods are known as goitrogens.Known goitrogens are vegetables from the cruciferous family: broccoli, brussel sprouts, cabbage, cauliflower, kale, collards.  Consumed in high amounts (especially raw) they are known to cause swelling of the thyroid gland leading it to become over- or under-active.

What Are The Symptoms?

The symptoms of an over- or under-active thyroid can creep up on you so stealthily and be so seemingly unrelated to one another that it’s only when you get a diagnosis that you start to connect the dots. Some of the most common symptoms are as follows:



What To Do If You Suspect Thyroid Problems?

If you have any of the above symptoms and suspect you have a thyroid condition you will want to have comprehensive thyroid bloodwork done. Many doctors will only test for TSH (thyroid stimulating hormone) but this alone is not the best screening test for thyroid conditions because, even if your TSH values are normal, your body may still not have enough thyroid hormone available. I usually recommend screening for TSH, free & total T3, free and total T4, antithyroglobulin hormone and anti-TPO (thyroid peroxidase hormone). Another way to test is known as the Wilson’s Thyroid protocol. This involves taking your body temperature orally, three times throughout the day. If the readings run below the normal 98.6oF, your thyroid hormone production is not optimal.

In Summary

When the process of an autoimmune condition has begun, the white blood cells that should be protecting us and keeping us safe from the invasion of virus and bacterial infections turns rogue and starts an attack against our own body. Any tissue in the body is fair game for an autoimmune condition including the thyroid gland, which is more prone to attack from autoimmune processes then other body parts. In order to keep the body healthy and prevent stimulating the branch of the immune system that attacks one’s own organs we need to address one of the major triggers, food allergies and sensitivities.

By testing and addressing foods allergies and sensitivities we can reduce irritation and inflammation to the thyroid gland. People with autoimmune thyroid conditions, either Graves’ or Hashimoto’s, should absolutely adhere to a gluten-free diet as well as testing for other food sensitivities & allergies.

To find out more about my food allergies and sensitivities package, click here. If you would like to find out more about your thyroid or to do food allergy test you can contact me here.

Next week I will be discussing weight concerns and food allergies.


Dr. Maura Scanlan

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