Gennev Chief Medical Officer, Dr. Rebecca Dunsmoor-Su was interviewed by David Stewart of the SuperAge podcast for the women's health episode “HRT, Estrogen and Menopause, New Scientific Findings”.

In part two of five transcripts from the session, Dr. Rebecca shares estrogen’s impact on heart and brain health, as well as why some women are not good candidates for hormone replacement therapy. If you have wondered if hormone replacement therapy is right for you, read on. And please listen to the full podcast by visiting  

Estrogen’s impact on cardiovascular and brain health 

David: As progesterone goes to zero, estrogen goes very, very low, what are the other effects on the body from this? 

Dr.Rebecca: That's a really good question because I think we have lost sight of talking about the benefits of estrogen for a woman over the years with all the fear mongering around cancer, which we should also discuss separately. But estrogen is actually a really healthy hormone for women. So, we know that estrogen is active in basically every part of the body. It's active in the brain, in the cardiovascular system, the bones, it’s active in the genital region, obviously. And losing estrogen has significant impacts on women as they age. For example, let's start with the cardiovascular system. So, we for years knew that women didn't really start having their heart attacks until after menopause. There were a lot of theories by this was, there was this big Framingham nurses' study that came out looking at many, many nurses, and we're tracking their progress over the years, and we were seeing that, those women who started hormones, when they went into menopause were also not getting heart attacks. So, it was obviously protecting their hearts. We asked the question, what's happening there?

What it seems is that, estrogen is an anti-inflammatory molecule. So, at the cardiovascular system in the blood vessels, it's increasing pliability, reducing plaque. So, it's keeping those things healthier and younger in that sense, but it also alters the HDL, LDL ratio a little bit. So, women's HDL is a little bit higher before they go through menopause and actually goes down, and their LDL rises with menopause. So, we switch our lipid profile a little bit to look a little more masculine when we go through menopause. So, it's a heart healthy hormone if it's something you've had all along and continued. There is some datas showing that if you go through menopause, and then, wait 10 years, and then start estrogen, it's actually unhealthy for the heart. So, the big important thing there is that you've already been made those cardiovascular changes. Your vessels have become less flexible, you've built plaque in your vessels, and then, estrogen has the opposite effect because it also slightly increases blood clot risk. So, you can put clots on top of plaques and actually have strokes and heart attacks.

A lot of the benefit of estrogen is continuous estrogen. It doesn't work, you can't start later on. At the bone, estrogen helps us keep calcium in our bones. It helps prevent osteoporosis for women. It's actually a really, really good bone medicine. It's actually one of the things that the FDA has approved it for is for maintenance of bone health. In terms of the brain, there are a couple of different pathways to go down with brain health. One is just the general symptoms of menopause. A lot of women experience what we call brain fog. So, they just have some word searching difficulty and some memory changes as they start to transition through menopause, that does not last forever.  

David: I want to know, why is that? What's happening there?

Dr.Rebecca: I don't know that we fully know. There are actually trackable changes in brain function that you can see. Dr. Lisa Mosconi, who's the head of the Weill Cornell Alzheimer's research group did a brain function study, which I think they published in the last year. What they did was, they can actually track brain function changes in women going through menopause. The nice thing is they also checked on them a couple years later, and they recovered those brain functions with or without hormone. So, it's just something about the brain transitioning how it functions. Estrogen is active in the serotonin system, in the norepinephrine system, in the dopamine system, it's active in the memory centers, it's active everywhere in the brain. So, there's something that's going on as we transition out of the state. Our brain comes to a new steady state. But there's definitely a lot of women really noticed that.

The other thing that happens during this time is because of the effect on the brain is sleep gets disturbed. So, women get disturbed sleep as they transition through menopause. Usually, what they come to me and tell me is not that they can't fall asleep, they can all fall asleep. But at 2 or 3 o'clock in the morning, they wake up, they're up for two or three hours, their minds are racing, and they're just getting this very scattered sleep. We think that has a little bit more to do with progesterone. Progesterone is a bit of a calming hormone level of the brain. But estrogen, too, because when we're often waking with hot flashes, and then, they're up, and they can't get back to sleep. Sleep has tons of downstream complications including brain health, but also weight, and energy, and all sorts of things.Then, I lost bit for a minute there. Oh, yes. We've talked about the brain, we've talked about the cardiovascular system and the bones. What else is estrogen good for, what's good for our skin. It's good for our hair. It keeps our vaginal tissues young and healthy. There's a lot of just general benefit for the female body.

Why are some women not good candidates for HRT?

David: I've interviewed people who've said, "Well, I'm not a good candidate for HRT," or, "It doesn't work for me." Because everything you're telling me is, this seems like a really good thing to do. Why not?

Dr.Rebecca: There are a couple of categories of people for whom hormone replacement therapy is not a good choice. Category number one, women who've had breast cancer. So, if you've had breast cancer, and that breast cancer often is hormone sensitive, then, we are increasing your risk of recurrence by adding estrogen or progesterone back into the system. So, we just don't do that. Another category is, people who already have cardiovascular disease.So, if you already have known cardiovascular disease, and then we have this blood clot risk that we add on top, we can actually increase your risk of cardiovascular events. Then, the third category are often women who've had ac lotting disorder, or had a blood clot in the past, or have a strong family history, or a genetic reason why they might clot their blood. We're very hesitant to add estrogen to that system because it does slightly increase blood clot risk.

David: When you're doing HRT, are you adding both estrogen and progesterone or just estrogen?

Dr.Rebecca: That depends on whether or not a woman still has a uterus. So, as I said back in the beginning, progesterone's role in the cycling woman is to stabilize the uterine lining to get ready to implant a pregnancy. In hormone replacement therapy, its role is to keep that uterine lining from growing under the influence of estrogen. If you give estrogen alone to a woman with the uterus, her lining will grow and grow and grow, she'll have a ton of bleeding, but eventually, will also grow into endometrial cancer or uterine lining cancer. Progesterone stops that from happening. So, if a woman has a uterus, we give both. If a woman doesn't have a uterus, she doesn't actually need the progesterone arm. We usually start with just the estrogen. In rare cases, I might add progesterone if sleep is a huge issue for her, and we want to try it to see if it really calms the brain. But in general, we start with estrogen and then see if it's needed.

To find out if hormone replacement therapy is right for you, speak with a physician who specializes in menopause.  Together, they can help you weigh the risk versus the benefits, and prescribe the therapies that are right for you.

Continue to part 3 to learn about the need for quality sleep, and what you need to know about testosterone therapy in menopause.

Did you miss part 1? Learn about the hormonal journey and why hormone testing is not always helpful. And be sure to listen to the full podcast episode at


Gennev Staff

June 21, 2022

Medically Reviewed By

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