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Estrogen Dominance: Is It Affecting Your Health?

When researchers from l'Universite de Montreal recently tested the waters of the St. Lawrence River downstream of Montreal, they discovered levels of estrogen 90 times the normal rate. These estrogens were both the natural type (estradiol) occurring in all women and men, and synthetic estrogens, like the ones found in some contraceptive medications and medications used in hormone replacement therapy.

Although the original reason for the research study was to determine the cause of changes in the reproductive organs of fish, there are implications for humans as well. As many as one-third of a species of minnows in that portion of the St. Lawrence River were found to be developing ovaries within their testes.

Montreal has a 200 million dollar project in the works to install a new ozonation process at its waste treatment plant that environmental engineers are hoping will destroy not only estrogens, but other pharmaceuticals in human waste. The development of this type of technology is important to human health, as increased exposure to estradiol and synthetic estrogens can contribute to a troublesome physiological state called estrogen dominance.

Estrogen dominance is a term that was coined by the late Dr. John Lee, and is defined as the state of having too much estrogen in one's body relative to progesterone.

When left unaddressed, estrogen dominance may create a number of health challenges, some of the most common ones being:

  • Breast tenderness

  • Cervical dysplasia

  • Cold hands and feet due to thyroid dysfunction

  • Low or absent libido

  • Early onset of menstruation

  • Endometrial (uterine) cancer

  • Fat gain, especially around the abdomen, hips and thighs

  • Fibrocystic breasts

  • Hair Loss

  • Infertility

  • Irregular menstrual periods

  • Insomnia

  • Osteoporosis

  • Polycystic ovaries

  • Premenopausal bone loss

  • Uterine cancer

  • Uterine fibroids

  • Water retention, bloating

Before we review key recommendations for preventing and addressing estrogen dominance, let's review...

Estrogen and Progesterone Output During a Healthy Monthly Cycle

From the onset of puberty to menopause, a woman's body is designed to have estrogen and progesterone work together to fuel and regulate her monthly cycle.

The bulk of estrogen is released into a woman's blood circulation during the first half of her monthly cycle. Estrogen works to build the lining of a woman's uterus to prepare it for implantation of a fertilized egg should fertilization occur.

The bulk of progesterone is released into a woman's bloodstream during the second half of a healthy monthly cycle. During this time, progesterone acts to maintain the rich lining of the uterus that estrogen helped to build up during the first two weeks of her cycle.

If a fertilized egg successfully implants into the uterine wall i.e. if a woman becomes pregnant, her body must continue to produce a steady and significant stream of progesterone to maintain a thick and richly vascularized uterine wall throughout the course of pregnancy. This job of continuous progesterone production is handled nicely by a healthy placenta.

If there is no implantation/pregnancy, a woman's body stops producing large amounts of progesterone, which results in the thickened uterine lining sloughing off and being eliminated during a woman's monthly flow.

This cycle repeats itself about once every month until a woman experiences menopause, with estrogen dominating the first half of each cycle, and progesterone dominating the second half.

Getting Back to Estrogen Dominance

So how do people - mainly women and teenage girls in industrialized countries - develop estrogen dominance?

The main causes of estrogen dominance are as follows:

  1. Exposure to Xenoestrogens

    Xenoestrogens are estrogens that are produced outside of the body.

    Significant sources of xenoestrogens include:

    • Birth control pills
    • Hormone replacement drugs
    • Condom spermicides
    • Conventional personal care products, particularly cosmetics
    • Plastic cookware
    • Growth hormones found in factory-farmed animal products
    • Pesticides and herbicides
    • DDT
    • PCBs - polychlorinated biphenyls
    • Foaming agents in soaps and detergents

  2. Being Overweight

    Estrogen is produced in three different areas of the body:

    • Ovaries (testicles in men)
    • Adrenal glands
    • Fat cells

    That's right. Estrogen is produced by fat cells. The more fat cells a person has, the greater chance he or she has of experiencing estrogen dominance.

  3. Chronic Stress

    When a person experiences chronic physical and/or emotional stress, his or her body will begin to convert progesterone into the stress hormone, cortisol. In fact, we now know that when a woman experiences significant stress during pregnancy, she may actually draw upon her baby's progesterone stores to manufacture enough cortisol to deal with her stress. The point is this: stress can lead to a depletion of progesterone, which creates the same condition of estrogen dominance that a woman experiences when she has too much estrogen in her system.

So, what can you do to prevent or address estrogen dominance?

  1. Clearly, you must strive to avoid unnecessary exposure to xenoestrogens. Study the list of xenoestrogens above and do your best to avoid them.
  2. Because fat cells produce estrogen, reaching and maintaining your ideal body weight is essential to addressing chronic estrogen dominance.
  3. Finally, estrogen dominance must be addressed in part by making a conscious and consistent effort to manage emotional stressors effectively.

If your food and lifestyle choices are in alignment with the suggestions listed above, your body stands a good shot at preventing or recovering from estrogen dominance.

Please note: A more thorough look at this topic would require a technical discussion of the entire endocrine system. The purpose of this article is to give you a clear understanding of what estrogen dominance is, how it develops, and how you can prevent or overcome it.

If you would like to study this topic in greater depth, I recommend that you read

Taking Charge of Your Fertility: The Definitive Guide to Natural Birth Control, Pregnancy Achievement, and Reproductive Health (Revised Edition) for a comprehensive look at female reproductive health,


What Your Doctor May Not Tell You About Premenopause : Balance Your Hormones and Your Life from Thirty to Fifty for a thorough look at endocrine imbalances that can contribute to uterine fibroids.


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