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. Today we 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 found in the water supplies used in farming. Since we eat multiple times per day, the exposure to these chemicals from food and water 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.
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, and oxybenzone.
Oxybenzone is a chemical used in many sunscreens and products with SPF has been studied and shown to disrupt thyroid hormone receptors and inhibit the activity of thyroid peroxidase. Parabens are a group of chemicals commonly used in many skincare products as preservatives, and they have been found to reduce thyroid hormone levels. Phthalates are another group of chemicals used in many skincare products for their function as solvents and stabilizers. Phthalate exposure can inhibit the binding of thyroid hormone to its receptor. They have been shown to lower total T4 or T3 levels and increase TSH levels, or in other words, can induce a state of hypothyroidism.
Household Products
Many common household products contain various types of chemicals that can disrupt normal thyroid function. These include, but are not limited to triclosan, plasticizers such as bisphenol A (BPA), and per- and polyfluoroalkyl substances (PFAS).
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. Bisphenol A (BPA) is a chemical found in many common household products due to its use as a plasticizer. BPA is found in many items made from vinyl, such as vinyl flooring, shower curtains, and tablecloths. Many plastic children’s toys also contain BPA, as well as many plastic water bottles, adhesives, food packaging, and canned goods. BPA can interfere with thyroid hormone synthesis, transport, and metabolism. BPA concentrations were also found to be associated with thyroid peroxidase (TPO) antibody positivity, which suggests that BPA can induce thyroid autoimmunity.
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 negaive effects on thyroid function including impairment of iodine uptake by thyroid cells, interference with thyroglobulin synthesis, modification of TPO activity, and disruption of the thyroid hormone signaling pathway.
Tips on Avoiding Exposure
- Buy skincare products that are free of parabens, phthalates, 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, especially microwaving food in plastic containers
- Invest in stainless steel or glass water bottles and food storage containers to use at home
- Use a high quality water filter in your home
- Buy organic produce whenever possible, as this will limit your exposure to some of the most offending pesticides and herbicides to your thyroid health
- Replace any PFAS containing non-stick cookware in your home with cast iron, stainless steel, or ceramic coated cookware