by Dr. Will Cole
Millions of people struggle with the annoying and debilitating symptoms of low thyroid hormones. Some of these people get lab tests that show low thyroid hormones, but many more have labs that come back “normal,” and they are left without answers or solutions to their symptoms, which can include anxiety, irritability, depression, brain fog, weight gain, and fatigue. Why would someone experience symptoms of low thyroid hormone in the first place. In my practice, I have discovered that one major underlying factor that isn’t normally addressed in the standard model of care is toxin exposure.
Toxins are often a significant piece of the complex thyroid puzzle. Fortunately, you can take steps to minimize your exposure to these 11 offenders, and doing so might help to restore your thyroid health and resolve your symptoms.
Perchlorate is a manufacturing by-product of rocket and jet fuel production. It can also come from the manufacturing of car air bags and fireworks. This toxin leaks into drinking water and food supply chains, and almost all of us have some perchlorates in our bodies, according to the CDC. This CDC study not only found widespread perchlorate exposure in humans, but a connection between perchlorate levels and thyroid hormone levels.
Perchlorate can prevent the production of thyroid hormone, which can lead to low thyroid symptoms. One study found babies born with elevated levels of thyroid-stimulating hormone which may have been affected by small amounts of perchlorate in their mother’s drinking water. These studies, and the work of the Environmental Working Group, show that not only is perchlorate exposure pervasive, but that even low levels of perchlorate exposure can have negative health effects on the thyroid. Choose drinking water that has been purified to avoid this toxic chemical.
Polychlorinated biphenyls (PCBs) are persistent industrial chemicals that were banned in the 1970s but are still detected in our environment today. PCBs have been shown to increase thyroid dysfunction, and, by increasing the level of thyroid-stimulating hormone, can make your body resistant to they thyroid hormone due to overexposure, similar to the way insulin resistance (seen in type II diabetes) is the result of chronic high levels of circulating insulin.
PCBs can also affect the liver enzymes that regulate the conversion of thyroid hormone, causing it to be less available in your body. PCBs are stored in fat and may be present in fatty fish from polluted waters or in well water in contaminated areas. Be careful about sourcing your seafood and the purity of your drinking water to further minimize exposure.
Dioxin is a highly toxic herbicide that is the primary component of Agent Orange, to which so many were exposed during the Vietnam war. Dioxins (like PCBs) are known to have disruptive effects on the endocrine system, and I have seen many patients who served in Vietnam, whose current thyroid problems are likely related to Agent Orange exposure.
Soy may not sound like a toxin but the phytoestrogens in soy proteins can have a toxic-like effect on the thyroid because they have been found to inhibit thyroid peroxidase. Soy is able to disrupt normal thyroid function by inhibiting the body’s ability to use iodine, blocking the process by which iodine becomes the thyroid hormones, inhibiting the secretion of thyroid hormone and disrupting the peripheral conversion of T4 to T3. Researchers have also found that infants fed soy formula had a prolonged increase in their thyroid-stimulating hormone (TSH) levels compared to infants fed non-soy formulas. In addition to its thyroid-impacting effects, soy is also one of the most commonly genetically modified foods (GMOs). As we still do not fully understand how GMOs affect human health, this is something additional to consider.
There are many different types of pesticides, but their use is ubiquitous and many antifungals and weed killers used on produce have been shown to decrease thyroid function and increase weight-loss resistance. One study found that women married to men who used pesticides in their daily work (such as in farming or landscaping) were at a much higher risk of developing thyroid problems than other women. Another study warns that about 60 percent of pesticides used today may affect the thyroid gland’s production of hormones. Choose organic foods to minimize this effect!
6. Flame retardants
According to several studies, flame retardants, or polybrominated diphenyl ethers (PBDEs), can disturb thyroid function. Flame-retardant chemicals are found in television and computer screens, as well as in the foam used for furniture and carpeting padding, and many of us have PBDEs in our bodies already, which have been linked to behavioral and developmental problems. Using natural products in your household could help reduce your exposure.
Plastics are bad for the environment. We all know that. But they can also be hazardous to your body’s environment. Antimony, a chemical that leaches from plastic bottles, is one concern. Researchers at the University of Copenhagen found antimony levels in fruit drinks and juices in plastic bottles at levels 2.5 times higher than what’s considered safe in tap water! Phthalates in some plastics have been shown to decrease thyroid function. Bisphenol A (BPA) – also used in plastics, food can coatings, and dental sealants – decreases thyroid receptor site sensitivity, causing thyroid resistance, similar to PCBs. Best to avoid plastics as much as possible. Store food in glass or steel containers, and never heat food in plastic.
Non-stick may be convenient, but that convenience comes at a price. One study found that perfluorooctanoic acid (PFOA), a chemical used to make Teflon, food wrappers, and other products, can affect thyroid function even at moderate levels of exposure. A study in Environmental Health Perspectives found that higher concentrations of PFOA are associated with the thyroid conditions that are seen today. Try getting to love stainless steel cookware and store your food in glass containers to avoid exposure to this chemical. Also minimize your consumption of packaged food, as the packaging may contain PFOA.
Exposure to halogen such as fluoride and chloride can lead to a decrease of iodine transport, since these chemicals are molecularly similar to iodine. This similarity means that halogens can occupy your iodine receptors in place of iodine, making the body’s iodine levels unusable. This can subsequently block the conversion of T4 to T3. This reduces your level of the active form of thyroid hormone. Specifically, even at low doses of just 2 to 5 mg per day, fluoride has been found to suppress thyroid function. You can absorb these halogens through your food, water, medications, and the environment, so keep your diet and environment as clean as possible and if you are able, work with your doctor to minimize the use of non-crucial medication.
10. Heavy metals
Mercury, lead, and aluminum can all trigger antibody reactions in the body, which can lead to autoimmune thyroid conditions such as Grave’s disease and Hashimoto’s disease. While you may have heard of acute heavy metal poisoning that would show up on a conventional blood test, this is a slower, more chronic type of heavy metal toxicity which can only be accurately demonstrated with a urine test using a chelating agent. The chelator will pull the metals from your cells where it has leached, so it can actually be measured on the test. A functional medicine practitioner can order this test and help you pinpoint the source of the toxicity so you can eliminate it.
11. Antibacterial products
So you thought that antibacterial soap was protecting you from disease? In 2016 the FDA banned the use of triclosan and other chemicals in hand soaps because they were deemed unsafe. The triclosan that was previously used in these antibacterial soaps is a chemical that is an endocrine disruptor and impacts thyroid function. One recent study found that triclosan had an effect on thyroid hormones, and another showed that triclosan interacted with androgen and estrogen hormone receptors. Best to use good old-fashioned products without this added ingredient. No need for this chemical boost.
Every person is uniquely complex, with individual genetic tolerances for toxins and individual life situations that can influence specific exposures. Think of your genetic tolerance as an empty bucket. The toxins you are exposed to gradually fill up the bucket. Some people’s buckets are smaller than those of others, and therefore fill up faster. Some people have more drastic exposures than others and can fill up even a large bucket more rapidly. And some people can be exposed to all of these toxins and show no noticeable effects from them.
There is no “one size fits all” solution for resolving toxin exposure. It’s easy to say “I’m doomed, you’re doomed, we’re all doomed!” but knowledge is power. You can make informed decisions to decrease the level of stress your thyroid is up against. You can also investigate these underlying issues and address them head on with professional guidance. And lastly, remember, your body is amazingly resilient. It wants to heal.
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