Are You Exposing Yourself to These Thyroid Disrupting Chemicals?
Did you know that we are constantly exposed to a variety of chemicals on a daily basis that can disrupt the functioning of our thyroid glands? These chemicals can be very problematic and harmful to our health in general, and especially harmful to the thyroid. This blog will discuss some common thyroid disrupting chemicals that people are exposed to on a daily basis, common sources of exposure, and give some tips on how to limit your exposure to them.
Pesticides and Herbicides
The use of pesticides and herbicides in industrial agriculture is ever increasing. These chemicals are sprayed directly on the food that we consume and are also in the water supplies that are used on crops. Since we eat multiple times per day, the exposure to these chemicals from food can really begin to add up if measures aren’t taken to decrease your exposure.
Many classes of pesticides and herbicides have been shown in studies to impair thyroid function, including organophosphates, organochlorines, carbamates, pyrethroids, neonicotinoids, and phenylpyrazoles. These chemicals have the potential to disrupt thyroid function in many different ways. They can interfere with thyroid hormone gene expression, inhibit the ability for our thyroid gland to uptake iodine, bind to thyroid hormone receptors and transport proteins, reduce cellular uptake of thyroid hormones, and increase the clearance of thyroid hormones from the body.
Organochlorines have specifically been studied and shown to have a similar structure to thyroid hormones T3 and T4. This means they have the potential to mimic the activity of thyroid hormones and bind to their receptors in our bodies, leading to thyroid disruption. A study done in Brazil tested a population of people who lived in an area of high contamination of organochlorines. The study tested the potential relationship between 19 different organochlorine pesticides and thyroid hormone levels. It showed that the individuals who were exposed to high levels of these chemicals had a much greater prevalence of hyperthyroidism and anti-TPO antibodies compared to people living in regions with less exposure to these chemicals. This means there is the potential for these thyroid disrupting chemicals to also induce thyroid autoimmunity in some people.
Personal Care Products
Many of the products we put on our skin daily contain multiple chemicals that are endocrine disruptors. While there are numerous chemicals in personal care products that pose harm to thyroid health, the thyroid disrupting chemicals in personal care products that we will discuss today include parabens, phthalates, bisphenol A, and oxybenzone.
Parabens are commonly used in many skincare products as a preservative. Parabens have been found to reduce thyroid hormone levels. Phthalates are used in many skincare products for their function as solvents and stabilizers. Phthalate exposure can inhibit the binding of thyroid hormone to its receptors. Phthalates have been shown to lower total T4 or T3 levels and increase TSH levels, or in other words, can induce a state of hypothyroidism.
Bisphenol A (BPA) is found in many personal care products, including toothpaste, soaps, deodorants, and cosmetics, just to name a few. BPA can interfere with thyroid hormone synthesis, transport, and metabolism. Bisphenol A (BPA) concentrations were also found to be associated with thyroid peroxidase (TPO) antibody positivity, which suggests that BPA can induce thyroid autoimmunity. Oxybenzone found in many sunscreens and products with SPF has been studied and shown to disrupt thyroid hormone receptors and inhibit the activity of thyroid peroxidase (TPO).
Household Products
Many common household products contain various types of chemicals that can disrupt normal thyroid function. These include, but are not limited to, plasticizers, per- and polyfluoroalkyl substances (PFAS), triclosan, and flame retardants such as polybrominated diphenyl ethers (PBDEs).
Cleaning products are a common source of thyroid disrupting chemicals that are found in homes. Triclosan is one such chemical, which is added to cleaning products for its anti-microbial properties and has been shown to have thyroid disrupting effects.
BPA and phthalates, which were mentioned for their use in personal care products, are also used in other common household products since they are plasticizers. This includes items made from vinyl, such as vinyl flooring, shower curtains, and tablecloths. Many plastic children’s toys contain these chemicals, as well as many plastic water bottles, adhesives, food packaging, and canned goods.
Polybrominated diphenyl ethers (PBDEs), commonly known as flame retardants, are present in many common household items including furniture, carpets and carpet padding, clothing items, and even computer and TV screens. Flame retardants disrupt thyroid function because they have a similar structure as thyroid hormone, thus displacing thyroid hormone from binding proteins and preventing them from being transported in the blood. They can also bind to thyroid hormone receptor sites, which can block thyroid hormones from doing so.
Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic compounds that are commonly used in non-stick cookware, food packaging products, furniture, and many other common household items. PFAS have many negative effects on thyroid function including impairment of iodine uptake by thyroid cells, interference with thyroglobulin synthesis, modification of TPO activity, and disruption of the TH signaling pathway.
Tips to Reduce Exposure
It's certainly overwhelming to know how many thyroid disrupting chemicals we are exposed to in our environment, and this isn't even a complete list. It's impossible to avoid all of these chemicals entirely, but you can certainly take some steps to reduce your exposure where you can. Here are my top tips on how to reduce your exposure to many of these thyroid disrupting chemicals.
Buy skincare products that are free of parabens, phthalates, BPA, oxybenzone, and other endocrine disruptors
Use cleaning products made from natural ingredients, and especially avoid products that contain triclosan
Avoid the use of plastic products whenever you can (invest in stainless steel or glass water bottles and food storage containers to use at home)
Get a high quality air filter for your home that removes volatile organic compounds (VOCs) from your living space (look for air filters that include both a HEPA filter and an activated carbon filter)
Use a high quality water filter in your home (a whole house system would be ideal, but if you can't afford that, start with filtering your drinking water)
Avoid buying clothes with flame retardants or from "fast fashion" brands that use a lot chemicals in their manufacturing process (clothes made from GOTS certified organic cotton are always great)
Buy organic produce whenever possible as this will limit your exposure to some of the most offending thyroid disrupting pesticides and herbicides
Replace any PFAS containing non-stick cookware in your home with cast iron or stainless steel
