This is the third article in a multi-part series on the thyroid. Follow along as we explore how the thyroid works and how you can use The Myers Way® Four Pillars of Health to prevent, control, or reverse thyroid disease.

Toxins can wreak havoc on your body in many ways, increasing inflammation in your body, disrupting your hormones, putting you at risk for an autoimmune disease, and even causing cancer. As I discuss in my book, we are exposed to hundreds, if not thousands, of toxic chemicals on a daily basis that can accumulate in our bodies and significantly impact our health. In this article I’ll take a look at the three toxins that pose the greatest risk to your thyroid, and how you can minimize your exposure and clear them from your body.

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3 Toxins that Threaten Your Thyroid


As I’ve covered previously on my blog, mercury can be found everywhere from cosmetics to fish, to pesticides, to vaccines, to your dental fillings. What’s more, coal-burning plants emit over 70,000 pounds of mercury into the air each year, where it settles into our water, meaning even if you’re taking precautions to avoid it, you’re still being exposed. I’m sure you’re well aware that mercury is a toxic chemical that is not healthy for your body but did you know that it is particularly dangerous for the thyroid? In Part I of this series we explained that your thyroid needs iodine to produce its hormones (we will talk more about iodine later in the series). In fact, your thyroid is exceptionally good at absorbing any available iodine in your body. Unfortunately for your thyroid, mercury and iodine are chemically very similar to each other, so your thyroid is quick to absorb and store mercury too.

This creates a two-fold problem for your thyroid. First, if your thyroid is storing mercury in place of iodine, it won’t have enough iodine to produce adequate levels of T4 and T3 hormones, which can cause you to develop hypothyroidism.1

Second, it puts you at risk of developing an autoimmune disease. No one knows exactly how heavy metals like mercury lead to autoimmune disease, but research has shown a demonstrated link between the two, including a 2011 study that found that women with high mercury exposure were more than twice as likely to have thyroid antibodies.2

One proposed reason for why this happens is that mercury damages the cells of your thyroid gland (as well as other cells in your body) so much that your immune system can no longer recognize these thyroid cells as “self” cells. Another prevailing theory is that your immune system goes on high alert to get rid of the mercury, and this chronic state of inflammation stresses your immune system so much that it starts attacking your whole thyroid.


Perchlorate is a chemical used primarily to create rocket fuel, but is also used extensively to produce fireworks, and sometimes fertilizers. Due to runoff, it is commonly found in the water supply, as well as produce irrigated with perchlorate-contaminated water. Like mercury, perchlorate is chemically similar to iodine and is quickly absorbed by the thyroid, preventing it from absorbing enough iodine. Perchlorate competitively blocks iodine absorption so well that it was actually used as a treatment for Graves’ disease (to slow patients’ overproduction of thyroid hormones) in the 50’s and 60’s, but was abandoned after it was found to cause death by aplastic anemia,3 a condition where your bone marrow stops producing enough red blood cells.

A 2006 study by the Centers for Disease Control found that even very low levels of perchlorate exposure caused decreased thyroid function in women.4

The study also stated that “A combination of human activity and natural sources has led to the widespread presence of perchlorate in the environment,” yet it wasn’t until five years later, in 2011, that the Environmental Protection Agency determined that it met the criteria as a contaminant to be regulated. They still have yet to issue any actual regulations for public water systems.5


Nitrates are a group of nitrogen and oxygen-containing chemicals that are used in fertilizer and foods. Some foods like spinach and celery naturally contain nitrate, but other foods, primarily processed or cured meats like hot dogs and bacon, have nitrates added to them as preservatives. Just like mercury and perchlorate, nitrates are similar enough to iodine to competitively block its absorption, which reduces thyroid function, but they have also been linked to increased rates of thyroid cancer.

A 2010 study examined women’s nitrate intake via their water supply and diet to determine if increased nitrate exposure coincided with thyroid problems.6

In the quartile of women whose nitrate-water contamination was highest (although still only 1/5 of the EPA’s maximum allowed level) thyroid cancer was 2.18 times more likely than the women in the bottom quartile. When it came to dietary nitrate, women in the top quartile were 2.9 times more likely to have thyroid cancer and 24% more likely to have hypothyroidism than women in the bottom quartile.

How To Avoid Exposure & Reduce Your Toxic Burden

I take a two-fold approach to reducing your toxic burden. Part one is reducing your future exposure to toxins and part two is clearing your body of the toxins that have accumulated in your system over the course of your lifetime. I outline my approach in this blog post, in a podcast episode, and you can read about it fully in my book, The Autoimmune Solution. Here we will cover those strategies specifically for the three toxins that most threaten your thyroid.

Clean Your Air

Mercury can be found in the air near coal-burning plants, so to avoid breathing in mercury and increasing your risk for thyroid disease, I recommend using a HEPA filter in your home and office. I use AirDoctor® purifiers, which use HEPA technology that is more effective than traditional HEPA filters. The Sierra Club created an interactive map that allows you to see if there are any coal-burning power plants in your area.

Clean Your Water

Thanks to pollution and runoff, mercury, perchlorate, and nitrates can all be found in the water supply, and the EPA’s regulated levels for each are either unreasonably high or, in the case of perchlorate, nonexistent. To protect your water I recommend installing water filters on all of your taps and showerheads. Remember, chemicals can be absorbed through the skin too!

Buy Clean Food

Eating organic, grass-fed, pasture-raised food will significantly reduce your risk of exposure to toxic chemicals. Unfortunately, you can never 100% eliminate your risk of mercury and perchlorate contamination because even certified organic farming practices don’t account for public water sources being contaminated through runoff. But, if you use all of these strategies in conjunction, then the trace amounts that might get passed on through your organic food is not likely to have a large effect on you.

To further reduce your risk of mercury exposure, it is best to avoid eating fish that are particularly high in mercury, such as tuna, and instead stick with fish with lower levels of mercury, such as salmon. To reduce your nitrate exposure, purchases nitrate-free cured and processed meat products, or avoid them altogether.

Buy Clean Body Products

Like I always say, you aren’t just what you eat, you’re also what you apply to your skin! Some foreign-produced skin-lightening cosmetics, including products that claim to lighten age spots and freckles, were found to have dangerous levels of mercury by the Food and Drug Administration. 7

Although American-made products have more stringent regulations, they can still be full of harmful chemicals, many of which mimic hormones in your body and disrupt the endocrine system. The Environmental Working Group put together a helpful Dirty Dozen list of chemicals that impact the endocrine system, as well as Skin Deep®, a tool that ranks the risk level of cosmetic products and each of their component ingredients.

Know Your SNP Status

SNPs, pronounced “snips” and short for single-nucleotide polymorphisms, are genetic mutations that can affect all sorts of processes in your body. Three of these mutations in particular, two in the MTHFR gene and one in the GSTM1 gene, reduce your ability to detox heavy metals like mercury, so you need to take extra care to avoid exposure and use supplements to support your body’s detoxification process. You can test for these mutations through a regular lab or a 23andMe at-home test kit.

Examine Your Mouth

Most dentists use amalgam fillings, which contain mercury and emit mercury vapor that can leach into your bloodstream. If you have amalgam fillings I recommend seeing a biological dentist to discuss the impact it might be having on your health and your options for having them replaced.

Support Your Detox Pathways

To reduce your existing toxic burden it is important to support your liver, where most of your body’s detoxification takes place. Eating a diet rich in nutrients will support your liver, as well as eating actual animal liver. For a delicious way to incorporate animal liver into your diet, check out this week’s featured recipe: Organic Beef Liver with Bacon and Rosemary. You can also use supplements for additional detox support, such as glutathione (your body’s natural detoxifier), or a methylation support supplement to aid in heavy metal detoxification if you have an MTHFR mutation.

Reverse Chronic Illnesses So You Can Take Back Your Health!

Are you ready to beat your symptoms, regain your energy, and feel like yourself again? Whether you have Hashimoto’s, Graves’, or any of the hundreds of other autoimmune diseases, I want you to know you CAN reverse your condition!

Tens of thousands of people around the world have already taken back their health using my New York Times Bestsellers, The Autoimmune Solution and The Thyroid Connection. Are you ready to join them?

In each book you’ll learn how to address the true underlying causes of your symptoms using simple yet proven dietary and lifestyle changes. Best of all, you’ll get step-by-step, four-week plans to put all of the principles into practice and truly make optimal health a way of life!

Get your copies today!

he Autoimmune Solution and The Thyroid Connection - Amy Myers MD Books

Additional Resources

For more information, check out my interview with Todd LePine, MD, where we discuss how heavy metals contribute to vitamin D deficiency.