Natural estrogen is a hormone produced in women during various stages of their sexual development and maturity. It is produced by the ovaries when girls first start developing sexually, right through pregnancy and all the way to menopause, when estrogen levels drop. However, estrogen is also produced in males in small quantities, and scientists are learning more every day about the other important roles that estrogen fulfills in the body, including brain development.
Estrogen Production
Estrogen is the collective term for three important steroidal sex hormones: estradiol, estrone and estriol. They are the main female sex hormones, although small quantities are produced in males as well. Estrogen is produced in a multistep chemical pathway from the precursor cholesterol, which is converted into progesterone, then into androgens, including testosterone, and finally into estrogen through the action of the enzyme aromatase. Natural estrogen, which is produced by the body, should be distinguished from synthetic estrogen, which is made in a laboratory and often administered as a medication for certain conditions.
The Functions of Estrogen
The term estrogen is often mistakenly used interchangeably with estradiol, as this is the predominant female sex hormone responsible for most sexual development and functioning. Estrogen is produced in the ovaries of developing females around the time that girls begin to develop breasts and start their periods. It is responsible for stimulating the growth of sex organs such as the uterine lining, or endometrium, the ovaries and the breasts. However, its effects are far-reaching and scientists are only just learning what other key functions are regulated by this hormone. A 2009 paper by researcher Margaret McCarthy, published in "Neuroscience," describes the potent stimulatory effect that estrogen has on brain development.
Estrogen and the Menstrual Cycle
Estrogen also has an important function as a regulator of other hormones. The menstrual cycle is a finely tuned mechanism of mutual inhibition and stimulation of the female sex hormones, which are produced in the brain and ovaries, and which coordinate your monthly cycle. Estrogen levels are highest during the follicular phase of your cycle, when your uterus lining is being prepared for the release of an egg from the ovary and for potential implantation of an embryo. Levels will then drop off during ovulation but will rise slightly again in the week or so after this, a period known as the luteal phase.
Estrogen and Pregnancy
If you become pregnant, instead of your estrogen levels falling back to their original levels, they will rise in order to sustain the uterine wall and to promote the secretion of the hormones required to maintain a viable pregnancy. In this case, natural estrogen is also produced by the placenta, the organ attached to the developing embryo. Dr. Eugene Albrecht, professor of obstetrics/gynecology at the University of Maryland School of Medicine, and his team revealed findings of their 1997 study at the Society for Gynecologic Investigation's annual meeting, which showed that estrogen plays a key coordinating role in pregnancy and that without it, a fetus will not develop properly.
Estrogen and Menopause
For many decades, you continue to produce natural estrogen from your ovaries and you will continue to be fertile. However, around 50 years of age, your estrogen levels will drop significantly and you will experience fewer and less regular periods. This is because the delicate hormonal balance has been disturbed due to the fall in estrogen. The side effects that many women experience as a result of this imbalance include hot flushes and extreme emotions. If you would like more information on your estrogen levels, consult your physician.
References
- Estrogen and Bone Development
- Encyclopedia Britannica: Synthesis of Estrogen
- "Neuroscience"; The Two Faces of Estradiol: Stimulation of brain cell growth from Estrogen; Margaret McCarthy; Dec. 2009.
- Hormones of the Reproductive System: Estrogen and The Menstrual Cycle
- Science Daily: Estrogen Maintains Pregnancy
