The Thyroid, Your Hormones and Endocrine Disruptors

Endocrine Disruptors hormones thyroid BPA

You’ve eliminated gluten, started eating more saturated fat, stopped eating that white poison, sugar, and tried to minimise stress, yet you’re still feeling crappy. Maybe it’s time to look at how your thyroid and hormones are being effected by the environment you live in?

Ok so it’s not feasible to live in a bubble of fresh air, free from toxins and chemicals, eating only organic food and drinking pure water (you know, that fancy, wind dried stuff that you pay $50 a bottle for at your local artisanal juice bar…). But realising what sort of chemicals and toxins you are exposed to everyday can help you minimise the bad of the bad and hopefully quick start your hormones into doing their job properly.

You’ve probably come across the term ‘endocrine disruptor’ before, or at least heard of the negative effects chemicals can have on your health. So what is an endocrine disruptor we hear you ask? Endocrine disruptors are chemicals that can interfere with our body’s endocrine system, producing adverse reproductive, neurological, developmental and immune effects in both us and wildlife.

As the Environmental Working Group (EWG) says, “there is no end to the tricks that endocrine disruptors can play on our bodies: increasing production of certain hormones; decreasing production of others; imitating hormones; turning one hormone into another; interfering with hormone signalling; telling cells to die prematurely; competing with essential nutrients; binding to essential hormones; accumulating in organs that produce hormones”.

Simply, endocrine disruptors mimic our naturally occurring hormones, tricking our bodies into thinking they actually are them. But once we start to use these ‘hormones’ are body reacts differently to how it would if they were the actual hormones.

BPA Hormones thyroid

When absorbed in the body, an endocrine disruptor can decrease or increase normal hormone levels (left), mimic the body’s natural hormones (middle), or alter the natural production of hormones (right).

Endocrine Disruptors and the Thyroid

Given the essential role the thyroid has in our hormone production, exposure to endocrine disruptors can significantly impact its functioning. In fact, endocrine disruptors can interfere with nearly every step in the thyroid system.

Examples of Endocrine Disruptors’ impacts on the thyroid:

  • Endocrine disruptors can alter the thyroid-pituitary-hypothalamus axis through increasing T4 and stimulating the thyroid which can result in thyroid follicular cell proliferation, and in some cases, result in thyroid cancer.
  • It is well established that thyroid hormones are of special importance in the development of the brain, which, in utero, is dependent upon normal levels of thyroid hormones. Studies have shown that exposure to endocrine disruptors during pregnancy can result in significant cognitive problems for the unborn child.
  • Dioxin-like compounds and certain flame retardants, have a high degree of structural similarity with the thyroid hormones, T3 and T4. When we are exposed to these chemicals, they compete with our naturally occurring hormones for the thyroid hormone receptor and transport proteins.
  • Exposure to PCBs (or fire retardants) can reduce circulating levels of thyroid hormone, resulting in hypothyroidism.
  • Studies have shown that endocrine disruptors such as PCBs (or fire retardants) interfere with the way the thyroid hormone functions, but they don’t actually change the amount of the hormone found in the body. This is of interest as we know, our thyroid function is measured by hormonal tests.

Unfortunately, chemicals are not currently tested specifically for their ability to mimic, disrupt, or otherwise act as hormone disruptors. In our next post, we’ll discuss the most common endocrine disruptors and what you can do to best minimise your exposure to them.