Center for Research on Ingredient Safety

What do I need to know?

To understand endocrine disrupting chemicals, we need to understand a few basics, including our endocrine system and hormones.

What is our endocrine system and what does it control?

Our endocrine system works as a chemical messenger system that produces and sends regulatory hormones as signals throughout our bodies using our bloodstream.
 
Hormones are produced by our primary endocrine glands including the thyroid and adrenal glands. Other systems in our bodies have secondary endocrine functions like our liver, kidneys, and more.

What are hormones?

Hormones are signaling molecules produced by our bodies with diverse functions. They primarily communicate throughout our organs and tissues to help regulate our physiology and behavior, including digestion, metabolism, sensory perception, sleep, stress, growth and development, reproduction, mood, and more.

How do hormones work in the body?

Our primary glands produce most of the hormones and send them throughout the body to hormone receptors on the different types of cells in our bodies. When the hormone receptor receives the right hormone, it triggers a biological function.
 
It can help to think of it as a key with a keyhole. Our hormones are the keys, and the receptors are the keyholes. When we receive the correct hormone to the correct receptor it unlocks a specific biological function such as metabolism, reproduction, growth, and more.
 
Our bodies produce hormones and receive hormones in specific quantities to keep our systems functioning in equilibrium, or in other words, in proper balance.
 
However, when we receive too much or too little of a specific hormone our bodies may not respond in the appropriate manner.
 
Let’s look at a specific hormone, insulin. Our pancreas produces insulin which allows our body to use the sugar, glucose, for energy. It does that by signaling to our liver and muscles to absorb glucose from our blood. When our bodies produce the correct amount of insulin our bodily system works properly. However, if our bodies don’t produce enough insulin or produce too much insulin it can result in too much or too little glucose in our bloodstream. When our blood sugar levels are outside the normal range it can be a sign of a serious condition like diabetes (high blood sugar) or hypoglycemia (low blood sugar).

What is an endocrine disrupting chemical?

Endocrine disrupting chemicals are compounds that can interfere with maintaining the appropriate balance of our hormones' by either change the amount of hormone being made or by mimicking the biological action of a hormone. However, this does not mean endocrine disrupting chemicals all cause harm.
 
Endocrine disrupting chemicals like the kind found in prescribed pharmaceuticals can be incredibly beneficial to the recipient. For example, birth control pills can either contain the hormones progestin and estrogen or progestin only, both of which are also naturally made in women's ovaries. By artificially changing the amount and timing in the rise of these two hormones by taking a pill, women can avoid pregnancy. Birth control can also help with specific medical conditions. 
 
However, endocrine disrupting chemicals such as contaminants found in large enough quantities that are not prescribed and monitored by a healthcare professional have the potential to cause great harm to the body and we can face a number of adverse health outcomes such as cancer, reproductive health issues, cognitive deficits, and obesity (1).

The good news.

Understanding this foundational information will help us understand how endocrine disrupting chemicals impact our bodily functions. In the next installation of this series, we’ll dig deeper into endocrine disrupting chemicals and our health.