Getting to know estrogen
Estrogen is best known as the female reproductive hormone that plays an important role in making women biologically female. Here are some interesting lesser know facts about estrogen:
- There are three major estrogens produced in the body—estrone, estradiol, and estriol—each with its own role to play in the functioning of the body. The proportions of the three estrogens vary with the menstrual cycle and with age.
- Men have small amounts of circulating estrogens that are critical for their health.
- Estrogen receptors are found on every cell in the body, which shows the importance of these hormones on all of the body’s tissues and functions.
The ebb and flow of estrogens (mainly estradiol) during the reproductive years are integral to the menstrual cycle and are linked to the cyclic symptoms that many women experience. Estrogens’ relative absence after menopause (when estrone predominates) contributes to a wide array of age-related degenerative changes including bone breakdown, vaginal tissue atrophy, and loss of skin elasticity.
The ties that bind
The cellular receptors for estrogen are not as specific as you might think. Many chemicals resemble estrogen enough to bind and activate estrogen receptor sites. In fact, xenoestrogens, or “environmental hormones,” such as PCBs, bisphenol A, phthalates from plastics, and chemicals used as preservatives, detergents, and herbicides and insecticides, are ubiquitous in our modern environment and are well known for their potent estrogenic activities.
Phytoestrogens are not estrogens but are plant compounds that can bind to estrogen receptor sites. They are widely found in nature, but, unlike xenoestrogenic pollutants, phytoestrogens have very weak estrogenic activities and do not interfere with normal hormone activity in the body.
Introducing lignans and isoflavones
There are two main sources of phytoestrogens: lignans and isoflavones. Lignans are a part of plant fiber, while isoflavones are in a family of plant chemicals known as bioflavonoids. Both lignans and isoflavones are actually converted into phytoestrogens through metabolic processes that include breakdown by bacteria living in the colon.
Phytoestrogens are thought to be important moderators of estrogen activity. Because they compete with estrogen for receptor sites, they are considered to be anti-estrogens in reproductive aged women whose estrogen levels are relatively high. In postmenopausal women, however, their weak activation of empty receptor sites makes them mildly pro-estrogenic.
Phytoestrogens and health
Phytoestrogens have been found to have antiviral, antifungal, antibacterial, anti-inflammatory, and anticancer properties. Dietary phytoestrogens, particularly from soy, appear in several studies to reduce breast cancer risk, although some studies have found no effect. Some preliminary studies suggest that they may also protect against prostate and colon cancers. There is no evidence to suggest that eating soy foods and flax seeds, or taking phytoestrogen-rich medicinal herbs, increases the risk of any type of cancer or any chronic disease.
The anti-estrogenic properties of phytoestrogens in cycling women make them useful in treating conditions associated with estrogen excess, such as PMS, fibrocystic breast changes, and uterine fibroid tumours. Black cohosh, dong quai, wild yam, and red clover are among the many phytoestrogenic herbs used to treat these conditions. Eating organic soy foods and taking a tablespoon or two of ground flax each day can also help women with these conditions. Phytoestrogens’ pro-estrogenic properties make these same herbs and foods useful in preventing and treating peri-menopausal symptoms such as hot flashes and mood swings.
Start simple
When a woman develops a condition related to hormone imbalance, it is usually wise to use dietary and lifestyle changes as the first treatment approach, and support these changes with phytoestrogenic herbs. Herbs can often be chosen for their secondary side-benefits. For example, if a woman has anxiety and insomnia during the peri-menopausal transition, her herbal formula should include motherwort; a woman with PMS who also gets acne may do well with red clover and wild yam in her formula; for hot flashes and hormone-related migraines, dong quai is a must.
Because of the risks associated with long-term hormone therapies, it is wise to turn to these only if diet, lifestyle and herbal medicine are not effective. Fortunately, most women do experience relief from hormonal symptoms using natural medicine.
phytoestrogen content of some foods
