|“Other chemicals have mixed effects, acting on all of our hormone receptors. These endocrine or hormone disruptors have been found in the body fat and breast milk of humans [and animals] throughout the world.”
Gender Benders & Endocrine Disruptors around You
By Elizabeth Lee Vliet, MD
For years, I have been exploring the links between environmental chemicals and their effects on our endocrine system. These synthetic, hormone-like substances interact with the estrogen receptors in our body, sabotage our hormones, and increase our long-term risk of disease.
Other chemicals have mixed effects, acting on all of our hormone receptors. These endocrine or hormone disruptors have been found in the body fat and breast milk of humans throughout the world, and well as in terrestrial and aquatic animal life. They are often called gender benders, for reasons that will become apparent later.
Many of these chemicals—such as dioxin, DDT, PCBs, and others—have been linked with increasing rates of cancer and endometriosis. But there are ominous signs that they also damage ovarian function, contributing to the alarming rise in female infertility, ovarian cysts, PCOS, hormone-triggered depression and anxiety, premature ovarian decline or failure, and immune disorders.
What Are Endocrine Disruptors and What Do They Do?
Certain man-made chemicals can act like hormones in the body. Because they persist in the environment for decades or even centuries without being broken down, they are also called persistent organic pollutants, or POPs. POPs pack a whollop to our endocrine system and our bodies: They may accentuate or disrupt, or completely alter or even block the actions of multiple body hormones, and not just estrogen.
Since POPs can mimic or block testosterone, thyroid, insulin, or other hormones, they fit under the broader category of “endocrine disruptors” and can affect anything in our body that is governed by hormones, which means just about everything! There are already hundreds of known POPs, and potentially thousands more.
Diethylstilbestrol, or DES, is a case in point. DES is a highly potent estrogenic compound that was first synthesized in Britain in 1938. Believing that it would prevent miscarriages, doctors subsequently prescribed DES to over 5 million women in the United States, Europe, and Latin America.
Later, DES was even more widely used, with the idea that it would create healthier pregnancies and stronger, healthier babies. Its application was further expanded to include emergency “morning after” contraception, to suppress milk production in women who did not want to nurse, and for treatment of menopausal symptoms like hot flashes. It even became a way to stop growth in teenage girls who were becoming “too tall!” DES was added to animal feed to fatten livestock and given to chickens speed their development. Human ingenuity compiled an absolutely staggering list of uses for DES.
Some Health Consequences of DES
Clearly DES, and more broadly all POPs, can cause a wide range of serious health problems. But it is their specific ability to interfere with sexual development and gender-specific behavioral function that has earned them the dubious distinction of being called “gender benders.”
Why Are Endocrine Disruptors Such a Problem Now?
The short answer is that none of these organic compounds existed before the 1930s. Most have been invented in the “chemical age” that started just prior to WWII. During the period from roughly 1970 through the 1990s, the first human generation ever exposed to DDT and other POPs during fetal life began reaching their own reproductive age. Subtle disruptions began to appear.
Timeline of Synthetic Endocrine Disruptors (POPs)
Where Are Chemical Endocrine Disruptors Found?
Simply put, they are now everywhere. Man-made endocrine disruptors, or POPs, are found in the plastic linings of canned goods, plastic food wrappers, detergents, herbicides, hair dyes, cosmetics, cigarette smoke, and auto exhaust—to name just a few sources. They may even be found in the water we drink, the food we eat, and the air we breathe.
They are also unwittingly added to the environment. Substances that are flushed down the toilet or rinsed down the sink can end up in the water supply, bubbling up in rivers and streams. A U.S. Geological Survey on 140 waterways in 30 states tracked 95 different pollutants, with some surprising results: 74% of the samples contained insect repellents; 48% contained antibiotics; 40% contained reproductive hormones (e.g., birth control pill estrogens and progestins); 32% contained other prescription drugs; and 27% had chemicals used for fragrances. So you may want to think carefully about how you dispose of your old prescriptions!
Since POPs are fat soluble, they become concentrated in the fat tissues of fish, animals, and humans. Anyone or anything at the top of the food chain accumulates the most POPs in body fat because each step in the sequence adds a little more of the pollutants to fatty tissues.
Mechanisms of Endocrine Disruption
Environmental chemicals that mimic hormones may act is several different ways to disrupt normal body function. They: