Estrogen is a powerful hormone. We don’t want too little (see Part 1: Estrogen Deficiency), but we definitely don’t want too much.
The many types of estrogen
The tricky thing about estrogen is that it’s not one thing—it’s many different things. There is estradiol, our main estrogen from our ovaries. There’s also estrone from body fat 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. Read How Soy Affects Hormones.
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 damages gut bacteria so it also impairs estrogen metabolism or detoxification.
2) Impaired metabolism or 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 can cause or worsen PMS (see Kate’s story in Chapter 11 of my new 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 can become very deficient during perimenopause and cause mood symptoms. Please read Why Stress Hits Hard in Your 40s.
How much estradiol is too much estradiol?
At its highest point, your estradiol should not exceed 270 pg/mL (1000 pmol/L) on a blood test. Unfortunately, estrogen 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).
Body fat makes an estrogen called estrone. When you’re young, too much estrone can impair ovulation and cause polycystic ovarian syndrome (PCOS). When you’re post-menopause, too much estrone can increase your risk of uterine cancer.
5) Receptor hypersensitivity
Your actual amount of estrogen is only part of the story. What really matters is your response to estrogen and that happens at the estrogen receptors. You have estrogen receptors in each and every part of your body including your brain, bowel, thyroid, and muscle. They’re stimulated by estradiol. They’re also stimulated by reabsorbed estrogens from your bowel (see detoxification section above), and to xenoestrogens such as pesticides.
Your estrogen receptors become more sensitive or less sensitive depending on many factors. For example, they become more sensitive in the presence of chronic inflammation or histamine, which is why inflammatory foods like dairy cause period problems. They become more sensitive when you’re deficient in iodine (read my Iodine post). They become less sensitive when they’re sheltered by the phytoestrogens from legumes, nuts, and vegetables.
When you’re a young teen, your estrogen receptors are naturally more sensitive and that can cause 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 flow. See Chapter 9 of my book and also 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 disease in which endometrial tissue grows throughout the pelvis. Endometriosis is worsened by estrogen excess but it is not caused by estrogen excess. Endometriosis responds best not to hormone treatment, but rather to anti-inflammatory, immune-modulating treatment. Please read Endometriosis: 5 Natural Treatments That Really Work.
How to reduce estrogen
- Don’t take hormonal birth control.
- Reduce alcohol to promote liver conjugation and the healthy metabolism or detoxification of estrogen.
- Eat vegetables to promote liver conjugation, feed healthy intestinal bacteria, and shelter estrogen receptors (phytoestrogens).
- Avoid antibiotics to maintain healthy intestinal bacteria.
- Maintain a healthy body weight to reduce the production of estrone in fat cells.
- Avoid inflammatory foods such as dairy to reduce estrogen receptor hypersensitivity.
- Minimise exposure to xenoestrogens such as plastics and pesticides.
Best supplements to reduce estrogen
- DIM. Diindolylmethane is a phytonutrient from cruciferous vegetables like broccoli and brussels sprouts. It promotes the conjugation and detoxification of estrogen. I recommend 200 mg per day with food.
- Calcium d-glucarate. Glucarate is a small molecule that’s made by the body and is 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 the next post.
Yours in health,