How Estrogen Works in the Brain
Estrogen has the following effects that individually or together may be responsible for its promemory actions:
1. Promotes the growth and survival of cholinergic nerve cells in the brain, probably by stimulating a substance called nerve growth factor.
2. May reduce destructive amyloid formation that occurs to a small extent during normal aging and to a precipitous degree in Alzheimer’s disease.
3. May diminish the inflammatory response in the brain. Abnormal immune reactions are believed to underlie many brain disorders and may contribute to age-related memory loss.
4. Helps to maintain synapses, which are the small gaps between nerve cells bridged by chemical neurotransmitters. This action may prolong the integrity and life of synapses that normally decay during the aging process.
5. Has moderate antioxidant properties.
6. Raising estrogen levels in mice improves performance on memory tasks such as remembering how to traverse a maze.
Types and Dosage of Estrogen
There are different types of estrogen in the blood and in the brain— estriol and estradiol, for example— but they are all fairly similar in their actions. For postmenopausal women, estrogen ranks high on my list of medications to prevent age-related memory loss, and as a potential treatment for mild memory loss. If you have had a hysterectomy, the simplest therapeutic approach is to take conjugated estrogen, which is marketed as Premarin. The standard Premarin dose is a single tablet of
0.625 mg daily. If you have not had a hysterectomy, it is necessary to add progesterone, which is the other main female hormone. Combining the two reduces the risk of cancer of the uterus. You can achieve this by taking a single daily tablet of an estrogen-progesterone combination that contains 0.625 mg Premarin and 2.5 mg medroxyprogesterone acetate. There are over a dozen brands of estrogen-progesterone combinations on the market, but they are all about the same. They are all prescription medications, and you need to work out the exact doses, as well as the timing sequence of estrogen and progesterone therapy, with your doctor (internist or gynecologist).
Risks of Estrogen Therapy
Estrogen therapy stimulates estrogen-responsive cells in the breast and uterus, and hence slightly raises the risk of both breast and uterine cancer. A family history of breast or uterine cancer is a cautionary sign, but by itself it does not mean you shouldn’t take estrogen. Cynthia was unwilling to take the risk because her aunt had suffered from breast cancer. Her sister Myra did take the risk and benefited greatly from estrogen replacement therapy. During the last couple of decades, improved technology in early breast cancer detection has tilted the balance in favor of estrogen therapy, which is why I recommended it for Cynthia.
There is a small risk of clotting with inflammation of the veins— thrombophlebitis— which most commonly affects the leg veins. In rare cases, this can affect the larger leg veins and cause deep vein
thrombosis, which is a potentially dangerous complication because the thrombus or blood clot can enter the veins and lodge in the blood vessels that supply the lungs. If you have a history of this type of complication either while taking birth control pills or during pregnancy, do not take estrogen.
Other side effects include breast discomfort and resumption of uterine bleeding in postmenopausal women who have not had a hysterectomy, though this depends on the timing sequence of the estrogen-progesterone combination. If you take estrogen, you will need to be monitored by a physician, preferably a gynecologist, for side effects and complications using regular mammograms, ultrasound if necessary, pap smears, and pelvic/radiologic examinations.
Taken From: The Memory Program How to Prevent Memory Loss
and Enhance Memory Power
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