Estrogen – that quintessential hormone of femininity. Also known as oestrogen, it is actually a group of compounds named for their importance in the estrus (reproductive) cycle of humans and animals. It plays an important role in the menstrual cycle, and can influence key aspects of fertility. It is used in birth control pills (BCP) and hormone replacement therapy (HRT). Imbalances of this sex hormone are associated with some kinds of abnormal cell growth, menopausal syndrome, and infertility.
Where do estrogens come from?
This sex hormone is made primarily by the developing follicles of the ovaries, the corpus luteum, and the placenta. Its production is stimulated by the release of the pituitary gland’s Luteinizing hormone (LH), and it is synthesized from androgens (male sex hormones) by the action of the enzyme aromatase.
There are three naturally occurring forms, produced at different times of a woman’s reproductive life. They are called “steroid hormones” because of their distinctive 4 chain molecular structure. Testosterone, progesterone, glucocorticoids and mineralocorticoids are other steroid hormones.
E1 – estrone, predominate during menopause
E2 – estradiol, predominate in non-pregnant females
E3 – estriol, predominate during pregnancy
There are a range of natural and synthetic compounds which can mimic the effects of naturally occurring estrogen. They are known as “non-steroidal hormones”, and can come from synthetic material (“xenoestrogens”, ex. plastics), from plant materials (“phytoestrogens”, ex. soy) and from fungi (“mycoestrogens”, ex. silage).
What do estrogens do?
Both men and women have this sex hormone coursing through their bodies, but there are much higher levels in women of reproductive age. Estrogens are best known for their role in the development of secondary sexual characteristics (ex. breast development), the thickening of the uterine lining, and as regulator of the feedback loop of the hypothalamus-pituitary-ovarian axis.
Estrogens have been shown to increase metabolism, reduce muscle mass and increase fat stores, increase vaginal lubrication, thicken the vaginal wall, increase bone formation, influence blood coagulation, decrease LDL cholesterol, increase water retention, and reduce bowel motility. It is also considered to play a role in women’s mental health, since a sudden reduction in this hormone’s levels is correlated to a lower mood, while restoring hormonal levels has been shown to promote clinical recovery in menopausal women.
Low estrogen levels
If a woman’s body is not producing enough of this important sex hormone, symptoms may arise such as hot flashes, night sweats, vaginal dryness, anxiety, depression, or loss of libido. Hormone levels may be lower than desired because of a decreased ovarian response, menopause, hysterectomy, chemotherapy, poor diet, high stress, thyroid disorders, or insufficient body fat. Low steroidal hormone levels are primarily treated with lifestyle changes, alternative or herbal medicine, or hormone replacement therapy (HRT).
High estrogen levels
If a women’s body has too much circulating sex hormone, other symptoms may arise such as weight gain, uterine fibroids, fatigue, irregular periods, headaches, infertility, or depression. There may be too much circulating hormone because of ovarian overproduction, exposure to non-steroidal hormones, obesity, stress, or thyroid disorders. Hormone imbalances are usually treated with lifestyle changes, herbal medicine, or hormone replacement therapy (HRT).
Birth control pills are often a combination of estrogen and progesterone (called combined oral contraceptive pill, COCP). The former acts through the feedback loop to decrease hormones from the pituitary, stunting the growth of ovarian follicles. The later acts to stop the release of sex hormones from the hypothalamus. Both of these effects prevent ovulation. High hormone levels, therefore, can contribute to infertility by interfering with ovulation.
Progesterone and Estrogen Ratio
The relationship between these 2 steroidal hormones is intimate, and balance is important. Estrogen helps stimulate growth of endometrial lining, increases body fat, stimulates breast tissue and reduces vascular tone. Progesterone, on the other hand, helps maintain the endometrial lining, helps use body fat for energy, protects against fibrocystic breasts, and increases vascular tone.
According to experts, the progesterone : estrogen ratio should be about 200-300 to 1. If the ratio is lower than this, it represents what is called estrogen dominance, meaning there is insufficient progesterone to counteract the effects of the more proliferative hormone. In other words, the stimulating effects of the estrogen is not mitigated by the calming effects of the progesterone, and abnormal cell growth (including some forms of cancer) can result. Treatment to restore the ratio of hormones can be done through lifestyle choices, alternative medicine, or hormone replacement therapy (HRT).
Estrogen and Traditional Chinese Medicine
The effects of estrogen are similar to what we call “Kidney Yin” in Chinese Medicine. Kidney Yin is the nourishing and cooling aspects of the body, representing that which is precious and life-cultivating in the reproductive system. A deficiency of Yin produces “hot & dry symptoms” such as hot flashes, night sweats and vaginal dryness (corresponding to symptoms we see during menopause when estrogen levels are lower). An excess of Yin produces “cold & wet symptoms”, such as weight gain, fatigue, and infertility (similar to symptoms we see in PCOS, when estrogen levels are often higher).
Traditional Chinese Medicine originated without the concepts of hormones. It is the balance of nourishment versus the accumulation of dampness representing a harmonious state of the body’s Yin that Traditional Chinese Medicine strives to achieve. A balance of the warming and cooling functions of the body also signifies a balance of Yin & Yang, often indicating a regulated hormonal system. For women showing signs of Yin deficiency, our principle of treatment is to nourish the body and cool any heat. For those showing signs of excess Yin, our principle of treatment is to drain dampness, transform phlegm, and either warm the body or clear heat as needed. Establishing balance in the body often corresponds to improved levels of hormones, including estrogen.