Heavy Metals & Thyroid Function
Heavy metals are highly toxic elements that are both poisonous and hard for the body to eliminate. These substances are particularly damaging to the thyroid gland and can have harmful effects many years after exposure. Heavy metals’ delayed harm lies in the fact that the body stores these toxins in bone and body tissues in a desperate effort to get them out of the bloodstream. As we age, some of those bone/body-tissues break down and when they do, heavy metals are released back into the bloodstream where they again harm thyroid function.
The term toxic heavy metals references the relatively high density of toxic metals like lead, mercury, cadmium and thallium among others. However, there are lightweight metals/metaloids that have been found to be toxic such as aluminum. While aluminum is lightweight as metals/metaloids go, it builds up in body tissues over time and for this reason it is often mentioned with heavy metals. This article examines the negative effects that toxic heavy metals have on the thyroid gland. For more general information, see our other article on toxic heavy metals.
This page is part of our summer, 2019 series on thyroid health.
Heavy Metals & The Thyroid
While toxic heavy metals are damaging to the entire human body, the effects may go unnoticed for some time. Toxic heavy metals are harmful endocrine disruptors; this is a fancy way of saying that these metals damage the body’s hormone-producing glands. The thyroid gland is a small, butterfly-shaped organ located in the neck that is responsible for secreting hormones that keep many body processes in balance. The link between heavy metals and thyroid harm is clearly illustrated by the fact that people who live in areas with high heavy metal exposure, such as near industrial centers or near the sites of volcanic activity (I’m looking at you, Mt. Saint Helens), have increased risk of thyroid cancer (heavy metals & the environment). Scientists suspect that the link between heavy metals and cancer may be because heavy metals stop enzyme function, damage cell membranes, clog hormone receptors and cause oxidative damage to the entire body. Whatever the exact mechanism between thyroid cancer and heavy metal exposure, the link between these substances and harmful effects on the body is clear.
Even low-levels of cadmium interfere with mitochondrial function (the cell’s energy generator) in the thyroid, change the liver’s processing of thyroid hormones (leading to lower available T3/T4 hormones) and decrease the ability of cells to respond to thyroid hormones. Similarly, mercury inhibits the enzyme that converts thyroid hormone from the inactive version (T4) to the active version (T3). It also decreases overall levels of circulating thyroid hormones. Furthermore, mercury will lead to higher levels of anti-bodies against the thyroid. In this way, “autoimmune” thyroid issues can sometimes be due to mercury accumulation, rather than the body randomly trying to attack itself.
- Mercury that the body can’t eliminate gets stored in bones/tissue
- Bone loss can release mercury into the bloodstream
- Mercury in the bloodstream damages the thyroid
- Damaged thyroid cannot stop bone loss
- Further bone loss releases more mercury
- More mercury repeats this harmful cycle
Mercury, Bone Mass & Thyroid Health
Mercury’s link to thyroid autoimmune conditions becomes even more interesting when we consider the fact that mercury is stored in bone mass that is lost during menopause. Even more troubling, the thyroid is responsible for producing the bone-strengthening hormone calcitonin.
Reducing heavy metal exposure
- Do not feed children tuna. Mercury is especially toxic to developing brains; even once a month can be too much for their system.
- Limit your general seafood intake, seafood is a high source of mercury.
- Rinse your rice before cooking it. (But make sure your water is free from arsenic and other heavy metals first!) By rinsing rice and discarding the water before cooking, you can significantly reduce the arsenic levels. Unfortunately, brown rice typically has higher levels of arsenic than white rice.
- Eat organic foods when possible. Although pesticides are different than heavy metals, some pesticides contain high concentrations of heavy metals. In addition, having to detoxify the pesticides puts burden on the liver and diminishes its ability to detoxify other substances (such as heavy metals) from the body. Check the Environmental Working Group’s Dirty Dozen/Clean Fifteen list for foods that you should definitively buy organic and those you can get away with buying conventional.
- Eating a diet high in vegetables will help provide the body with the nutrients and antioxidants it needs to better protect itself from toxic substances.
- Remove shoes when entering the house to avoid tracking in automotive/industrial pollution from surfaces inside. Cities have particulate-matter pollution from arsenic and other heavy metals from car traffic, industrial businesses and other sources.
- Test tap-water by ordering a home test kit. Arsenic is a common heavy metal that can get into wells, especially near old orchards. Acidic water can leach metals like zinc, copper and lead from pipes into water supplies. We recommend Doctor’s Data water test kits. No, we do not get paid by them.
- Use air and water filters. Make sure that filters are rated to remove heavy metals. Air filters should be HEPA air filters.
- Wear proper protective equipment when working with paints, batteries, cars etc. Dispose of these items properly.
- Open windows and allow air flow through the house to avoid a build-up of indoor air pollution.
- Check for safe cosmetics: https://www.ewg.org/skindeep/
- Advice on fish consumption for children and women who are/want to become pregnant or are breastfeeding: https://www.fda.gov/food/consumers/advice-about-eating-fish
- Occupational Safety and Health Administration guidelines on toxic metals: https://www.osha.gov/SLTC/metalsheavy/index.html
- Recycling batteries and cell phones: https://www.call2recycle.org/locator/
A few resources for staying safe:
Toxic heavy metal testing
At Terrain Wellness, we prefer urinary testing because heavy metals do not stay in the bloodstream for prolonged periods of time. Some doctors perform blood tests for heavy metals but these tests only show cases of recent acute poisoning, but don’t indicate toxicity levels within bone and organ tissue. Hair samples may be a bit better, but the concentration can vary depending on environmental exposure (hair products, air, etc) and not all metal exposures are well-reflected in the hair. Lastly, urine is the major route where the body excretes heavy metals so if these substances are being detoxified from the body, it will show up in the urine.
Another key difference in our heavy metal testing protocol is that labs publish a “normal range” on their report, but their normal can be misleading. The problem is that laboratory reference ranges are based on results from the samples that they have tested; this skews the lab’s range of “normal” higher because people with doctor’s orders to undergo a heavy metal test are more likely to have elevated levels than the general population.
Instead of using a lab company’s standard interpretation, we compare test results against the more accurate National Health And Nutrition Examination Survey (NHANES) results. This program of studies was designed by the Center for Disease Control and Prevention (CDC) to assess the health and nutritional status of adults and children in the United States. Using these nationally established reference ranges allows us to have a more objective evaluation of whether or not a person has unusually high exposure compared to the general population.
Dr. Vy’s Lab Test Results Evaluated
Below, I’ve shared one of my own test reports. This test result was not perfect but I’m sharing it to educate my patients; we are all on this journey together. On the surface, the test results look okay because most of the heavy metals are within the lab’s reference range. This can be misleading however, because lab reference ranges are based on results from samples that the lab has tested. When we compare these results to NHANES/CDC safe levels, we see a different picture. The results also indicate that toxic metals can affect people who live healthy lifestyles. As we continue our journey toward improving our health, it will be interesting to see how much improvement I can get in my own test results.
Treating Heavy Metal Exposure
The first thing to do is identify the source(s) of heavy metal toxicity and eliminate the risk of further exposure. In serious cases where the body has high levels of heavy metals, IV chelation therapy may be recommended for certain patients depending on health status and the levels of heavy metals present. For those with lower levels of toxic metals, there are lifestyle changes that can also help the body process and remove these contaminants on its own.
Chelation therapy is the binding of a metal with a medicinal agent. There are both intravenous (IV) and oral chelation methods, which we recommend on a case-by-case basis as deemed appropriate for a patient’s health history. Since chelation is a sensitive medical process requiring multiple visits and close medical supervision, it may not be right for every patient.
- Exercise: helps move the lymph to clear toxins from the cells and sweating from exercise can clear toxins from the body
- Saunas: sweating helps clear toxins from the body
- Eating vegetables: especially sulfur-containing vegetables (broccoli, cauliflower, kale, cabbage, etc) promotes glutathione synthesis and supports sulfur-dependent detox pathways
- Water: making sure you are drinking plenty of (filtered) water and having consistent bowel movements (at least 1-2 per day). Heavy metals are mostly eliminated through the kidneys and some are eliminated through the stool, so keeping these methods of elimination moving are ways to help your body detoxify.
Ways to eliminate heavy metals that don’t involve chelation:
We hope you found this article both helpful and informative. If you are in the Portland area (or are willing to travel here) and need help with heavy metal detoxification, we are accepting new patients and would be honored to help you.
Yours in health,
Thanks for reading. We hope you found this article helpful. If you’d like to read more articles like this one or follow along with our summer, 2019 thyroid series, sign up below if you haven’t already.