So I’ve been reading up on estrogen. There are three main forms of estrogen: estrone, estradiol, and estriol. Deborah Blum does succinct work of describing estrogens in her book Sex on the Brain: The Biological Differences Between Men and Women. I quote from her work:
“Men make estradiol (mostly by enzyme conversion of testosterone, not only in the brain but in other cells, including fat, skin, and blood). Women make all three estrogens. Each is concentrated in a different part of he body and has its own place in the female life cycle.
The estrogens vary only slightly chemically; each has the same basic carbon-ring structure but a different number of oxygen and hydrogen molecules attached. Estradiol, made mainly in the ovaries, is the primary estrogen. It starts slowly rising in girls at about age eight. It continues to rise until puberty, starting about age 11, when it helps induce the menstrual cycle. It remains dominant until menopause, with one exception – pregnancy. During pregnancy, estradiol production shuts down. In its place, the placenta makes estriol, which stays high until a baby is born. At that point, estradiol kicks back in.
As you might expect, then, estrone is the primary estrogen of menopause. As the ovaries shut down production of estradiol with the onset of menopause, the fat cells start making estrone (although, as with men, women’s skin and blood cells can also make estrogens). The production of estrone, though is far less intense.” (p 191-192)
Today, with my estradiol levels at an all time low, I am preoccupied with the connection between estradiol levels and brain function.
One large survey, cited in Blum’s book, looked at 8,877 residents of a retirement community in Southern California.
“Two researchers from the University of Southern California, Annlia Paganini-Hill and Victor W. Henderson, examined the nature of the deaths of those residents, concentrating specifically on those who had suffered from senile dementias and those who had not. They found that among the women who died, those receiving estrogen therapy had a 30 percent lower risk of developing Alzheimer’s. A 1996 study found that even one year of estradiol supplements after menopause lowered the risk of Alzheimer’s…
What is it about estrogens that might buffer the brain so well and, by their decline, leave it so vulnerable? Animal research indicates that estradiol improves blood circulation in the brain, keeping up the health of neurons. The hormones also appear to stimulate nerve cell growth and branching in the exact regions of the brain so damaged by Alzheimer’s. For example, it appears that estradiol fosters the growth of neurons within the hippocampus, the region of he brain so closely associated with learning, memory, and spatial reasoning. Brain-imaging show that most Alzheimer’s patients suffer visible damage in the hippocampus – an erosion of the synapses that allow one neuron to talk to another.” (p 201)
But, there are discrepancies among authorities.
“Because of possible harm in some areas and lack of a demonstrated benefit in others, we have concluded that combination hormone therapy (estrogen & progestin) should not be prescribed at this time for older, postmenopausal women to maintain or improve cognitive function,” says Judith A. Salerno, M.D., M.S., Deputy Director of the National Institute on Aging (NIA) at the National Institutes of Health (NIH), U.S. Department of Health and Human Services [from http://www.nih.gov/news/pr/may2003/nia-27.htm].
I am fully aware that cognitive function is just one piece of the puzzle. With the body so complex, decisions of intervention, especially with synthetic substances, are also complex.
I stand open to input if anyone wants to throw in their two cents.
I stand open to input if anyone wants to throw in their two cents.
[My two recent losses:
1. ovaries (mentioned above),
2. the regular presence of my dear daughter
(all the best to you, Rebekah!)]
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