Estrogen is a powerful hormone. We don’t want too little (see Part 1: Estrogen Deficiency), but we definitely don’t want too much.
Many Types of Estrogen
The tricky thing about estrogen is that it’s not one thing—it’s many. There is estradiol, our main estrogen from our ovaries. There’s also estrone from adipose tissue, and numerous estrogen metabolites from intestinal bacteria. To top it all off, there are xenoestrogens or endocrine disrupting chemicals (EDCs), which are environmental toxins that act like estrogen. There are also plant estrogens (phytoestrogens), but phytoestrogens generally have an anti-estrogen effect in menstruating women (see my Soy post).
5 Causes of Estrogen Excess
1) Hormonal birth control
The estrogen in hormonal birth control is a xenoestrogen called ethinylestradiol. It’s much stronger than natural estradiol, and it further contributes to estrogen excess by altering intestinal bacteria (see the next point).
2) Impaired detoxification
All estrogens (including xenoestrogens) must be detoxified in a two-step process through the liver and bowel. Liver conjugation requires nutrients such as B-vitamins, selenium, and the amino acid glycine. It’s impaired by xenoestrogens and by alcohol, which is why women who consume more than one drink per day have measurably higher blood levels of estrogen, and a higher risk of breast cancer.
After conjugation, estrogens enter the bowel, where they should then exit the body. Problems with intestinal bacteria (such as too many gram-negative bacteria) cause estrogens to be de-conjugated (reactivated) and re-enter the body. That’s why antibiotics cause PMS (see Karen’s story in Chapter 8 of my book), and increase the risk of breast cancer.
Estrogen is erratic during the years before menopause. It swings from low to high, and back to low again. I call this the the perimenopausal estrogen roller coaster and it’s very unpleasant. Roller coaster symptoms include the hot flushes and insomnia of estrogen deficiency, and then the breast pain and irritable mood of estrogen excess just a few days later. The estrogen roller coaster is caused by rising FSH (follicle stimulating hormone), which stimulates ovaries to make more estradiol. Perimenopausal women can have double the estradiol of younger women. Progesterone is also deficient during perimenopause (see Estrogen Dominance section below).
How much estradiol is too much estradiol?
At its highest point, estradiol should not exceed 270 pg/mL (1000 pmol/L) on a blood test. Unfortunately, estradiol is difficult to test because it fluctuates greatly throughout the cycle, and even throughout the day. Estradiol is lowest on day 3, and highest about four days before ovulation (day 10 in a standard cycle). It’s then high again in the middle of the luteal phase, which is usually when I test it together with progesterone (which is also at its highest point).
Adipose tissue makes an estrogen called estrone. In a young woman, too much estrone impairs ovulation and can cause polycystic ovarian syndrome (PCOS) and too little estradiol. In a postmenopausal woman, estrone from adipose tissue is too much estrogen. Post-menopause, obesity and estrone increase the risk of endometrial cancer.
5) Receptor hypersensitivity
The actual amount of estrogen is only part of the story. What really matters is the response, and that happens at the estrogen receptors. There are estrogen receptors in each and every tissue including brain, bowel, thyroid, and muscle. They respond to estradiol. They also respond to de-conjugated estrogens from the bowel (see detoxification section above), and to endocrine disrupting chemicals such as pesticides.
Estrogen receptors are more or less sensitive depending on other factors. For example, they’re more sensitive when stimulated by inflammation, which is why inflammatory foods like dairy cause period problems. They’re more sensitive when deficient in iodine (read my Iodine post). They’re less sensitive when buffered by phytoestrogens from vegetables.
Estrogen receptors are naturally hypersensitive in the early years of menstruation, and that’s why some teens suffer heavy periods. Teen estrogen “excess” should settle down after a year or two, and in the meantime, there are simple non-hormonal ways to reduce a teen’s heavy flow. See my Heavy Period post.
What Is Estrogen Dominance?
Estrogen dominance usually means estrogen excess, but it can also describe a situation of normal estrogen and progesterone deficiency. I generally do not use the term ‘estrogen dominance’ because I prefer the more precise terms of ‘estrogen excess’ and ‘progesterone deficiency’. It’s common to suffer both conditions simultaneously. (See Why I Don’t Use the Term Estrogen Dominance.)
A word about the gynecological condition endometriosis. It is an inflammatory, autoimmune condition in which endometrial tissue grows throughout the pelvis. Endometriosis is worsened by estrogen excess but it is not caused by estrogen excess. Although estrogen-reducing treatments can help somewhat, endometriosis responds best to immune-modulating treatment. Please see my Endometriosis post.
How to Reduce Estrogen
- Don’t take hormonal birth control.
- Reduce alcohol to promote liver conjugation and detoxification of estrogen.
- Eat vegetables to promote liver conjugation, feed healthy intestinal bacteria, and buffer estrogen receptors (phytoestrogens).
- Avoid antibiotics to maintain healthy intestinal bacteria.
- Maintain a healthy body weight to reduce estrone.
- Avoid inflammatory foods such as dairy to reduce estrogen receptor hypersensitivity.
- Minimise exposure to xenoestrogens such as plastics and pesticides.
Supplements to Reduce Estrogen
- DIM. Diindolylmethane is a phytonutrient from cruciferous vegetables like broccoli and brussel sprouts. It promotes the conjugation and detoxification of estrogen. I recommend 200 mg per day with food.
- Calcium d-glucarate. Glucarate is normally made by the body in small amounts and is also found in foods such as oranges and broccoli. Glucarate conjugates and detoxifies estrogen (glucarate is the active part of this supplement—not calcium).
- Iodine down-regulates estrogen receptors, making them less sensitive. It is particularly helpful for breast symptoms such as tenderness or breast cysts. Iodine is safe up to a dose of 500 mcg (0.5 mg), but higher dose iodine can damage the thyroid gland. Please see my Iodine post.
- Natural progesterone. Progesterone counterbalances estrogen. It lightens periods, and improves breast tenderness and premenstrual irritability. When taken a supplement, a good starting dose is about 20 mg (¼ tsp of a 2% cream). Progesterone should be used only after ovulation, or it can suppress ovulation and progesterone. The progestins of hormonal birth control are not progesterone. I’ll discuss the difference between progestins and progesterone in next month’s post.
Yours in Health,