I know that many women are concerned about the effects of estrogen on their breasts. How could they not be? So much has been written and discussed about estrogen, especially since many of the medications for breast cancer have been created to inhibit estrogen production. While understanding estrogen’s role on the breasts is important, estrogen also effects many organs and functions throughout the entire body, like the heart, bones, skin, vagina, and, as will be discussed here, the brain.
Think how much your brain helps make you the individual woman you are–your wit, your wisdom, your winning ways. Estrogen can play an essential role in protecting your brain from certain illnesses and slowing the aging process if it is taken at the optimal time. As you’ll discover below, taking estrogen during your estrogen window provides the best benefits for brain health and a major opportunity for an estrogen fix.
The female brain’s relationship with estrogen begins almost at conception, leading it to differentiate distinctly from the male brain while in utero. For example, the corpus callosum–the bridge of nerve tissue that connects the right and left sides of the brain–is thicker in female fetuses than in male fetuses. Research shows that, in general, men’s brains connect more strongly from front to back and women’s brains connect more strongly from left to right. That’s why in general, male brains are “wired” for motor skills, while female brains in general are “wired” to be more analytical and intuitive. Estrogen stimulates the parts of a woman’s brain that have to do with emotion and cognition, making women naturally more empathetic and compassionate than their male counterparts.
How Estrogen Protects Your Brain
Estrogen affects neurons throughout the brain and functions both to protect and to stimulate nerves. Brain tissue studied in a petri dish showed that estrogen protects neurons from oxidative stress, low bloodflow, low blood sugar, and damage from amyloid protein, which is believed to contribute to Alzheimer’s disease. Estrogen has also been shown to stimulate nerves of the brain to grow, repair when damaged, and transmit signals more effectively through increased branching out of the tips of nerves called dendrites.
Estrogen also affects the neural transmitters between brain cells. These are the chemical messengers that allow one brain cell to communicate with its neighboring cells to say, “Pass it down.” How we think, move, feel, and behave–everything the brain controls–depends on the nerves of the brain rapidly communicating with each other to send a message to its destination: pull back our hand from a hot stove, cry when we are sad, put one foot in front of the other to walk or run, analyze a problem, and so forth. And the brain’s nerve cells, called axons, communicate by either sending electrical impulses between two nerve cells or by sending a chemical neurotransmitter, such as serotonin, dopamine, or norepinephrine, which is produced in the end of the nerve cells and released into a very small space between itself and the nerve it is trying to communicate with. Estrogen increases the amounts of these transmitters and the speed at which they are released, reabsorbed, or inactivated, all of which have a huge impact on mood. In other words, estrogen helps determine how quickly and efficiently our brains can do its job.
Estrogen also affects the brain’s blood supply. Brains need a lot of bloodflow to function at their best. In fact, the brain gets about 15 percent of the bloodflow from the heart in order to meet its oxygen and fuel requirements. Through a complex series of biochemical interactions, estrogen causes the release of nitric oxide in the blood, which causes blood vessels to expand. That, in turn, increases the amount of blood to the brain, which keeps brain tissues well oxygenated and healthy. When a woman is young and is producing lots of estrogen in her body, in addition to all its other jobs, that estrogen is keeping her brain optimally healthy and supplied with a rich, nourishing flow of oxygen. These are all the positive things estrogen therapy (ET) can continue to do if a woman takes ET during her estrogen window.
After menopause, especially after early menopause, lowered estrogen levels translate into a lower and less-oxygen-rich blood supply to the brain, and as you can imagine, this can have some pretty serious side effects, including an increased risk of Alzheimer’s disease. Yet you can create an estrogen fix and reduce this risk back to normal by taking supplemental estrogen during your estrogen window.
The importance of estrogen on blood vessels has been studied using Doppler ultrasound to determine estrogen’s impact on the brain. Menopausal women who did not take estrogen had less bloodflow in their carotid and cerebral arteries than premenopausal women with normal estrogen levels. The further the women were beyond menopause, the lower their brain bloodflow. In another study of bloodflow to the brain, menopausal women had Doppler ultrasound studies of their carotid arteries before and after starting hormone therapy. By the second month of treatment, women taking hormone therapy had significantly improved bloodflow over the entire 52 weeks of the study.
Throughout the body, estrogen also works like an anti-inflammatory to protect the walls of the arteries from developing plaque. The endothelial cells that line arteries have an internal protective mechanism that keeps them working properly and free of plaque. Disease or conditions like diabetes or obesity create inflammation in the blood vessel walls that leads to more plaque and cardiovascular disease. Substances like cytokines and free radicals contribute to the inflammation and are harmful to the endothelial cells.
Another important estrogen fix is how it works on the walls of blood vessels by protecting them from the damaging effects of cytokines that move immune cells toward sites of inflammation or infection and free radicals, and that reduces the risk of developing plaque inside of arteries. This beneficial effect is so powerful that when estrogen was injected into the arteries of rats’ brains just before the injection of a toxic substance, estrogen prevented damage to the blood vessel walls. Similarly, postmenopausal women who were followed for 10 years with MRI were found to have less brain injury caused by poor bloodflow if they were taking hormone therapy. The longer they took estrogen, the less damage was noted. Estrogen’s protective effects on the brain were also observed in both male and female patients who needed emergency resuscitation, specifically those with traumatic brain injury, shock, and sudden cardiac arrest. Typically, the entire focus of treating patients in such situations is to get the heart to start beating again or to get the person breathing again; the focus has not been on protecting the person’s brain. When women and men treated for sudden cardiac arrest were also given an intravenous combination of three things–estrogen, a strong antioxidant, and an anti-inflammatory drug–in order to protect the brain and increase survival, brain cell survival of participants treated with this regimen increased by as much as 65 percent. When doctors gave the same regimen intravenously after traumatic brain injury, they observed similar effects.
These are only some of the ways in which estrogen can serve as a salve for your brain. In my new book, The Estrogen Fix, you’ll discover in much more detail how estrogen protects your bones, breasts, bladder, skin, vagina, heart and more. You’ll also discover which estrogens are best, when to begin and stop them for maximum benefit, and what alternatives to take if estrogen is not for you.