By Bren Boston, MD
Many women who enter the transition into menopause will say, “I’m so frustrated! I can’t remember the word that’s on the tip of my tongue, or where I left my keys!”
While some of this can be chalked up to the fact that women in mid-life are typically juggling their whole family’s schedules, to-do lists, and endless multitasking, a decline in estrogen also plays a role.
Our brains have estrogen (estradiol) receptors that mediate protection of our brain cells (neurons). The estradiol receptors are clustered in areas of the brain like the hippocampus and amygdala that are important for memory and emotions. These areas are selectively impacted by neurodegeneration in Alzheimer’s disease.
Estradiol has a protective effect on the brain via improving blood vessel health which improves circulation and perfusion (blood and oxygen supply) of brain cells. There are estrogen receptors in the walls of blood vessels that stimulate nitric oxide production which dilates vessels and improves blood flow. Estradiol decreases lipid peroxidation, reducing atherosclerosis or plaque build-up in the arteries, which also improves circulation.
Brain mitochondria are rich in estradiol receptors. Mitochondria are the energy producers inside cells. Estradiol enhances brain mitochondrial efficiency, leading to more ATP or energy production and less oxidative stress, which helps to protect existing neurons and the growth of nerve tissue.
Bioidentical estradiol replacement therapy has an immediate cognitive benefit and future dementia protection. Studies suggest that hormone therapy may prevent cognitive decline associated with Alzheimer’s dementia in post-menopausal women. In these studies, decreased beta amyloid production, reduced oxidative damage, and reduced neurotoxicity was seen in women receiving estradiol compared to those who did not.
Bioidentical estradiol applied to the skin (transdermal patch or cream) of menopausal women has been shown to improve cognitive performance related to language and fine motor skills in multiple studies. In contrast, oral conjugated equine estrogen, when combined with synthetic progestins like in a birth control pill, is not associated with cognitive benefit. Synthetic progestins have been shown to reverse the benefits of estrogen. After menopause, estrogen replacement should be transdermal (on the skin), not oral, and should be bioidentical, not synthetic, to reap the cognitive benefits.
Bioidentical hormone replacement is not right for every woman. Talk to a doctor familiar with bioidentical hormone replacement to see if you are a candidate.