Women are works of art. On the outside as on the inside. I am a neuroscientist,
and I focus on the inside, especially on women's brains. There are many theories
on how women's brains differ from men's brains, and I've been looking
at brains for 20 years and can guarantee
that there is no such thing as a gendered brain. Pink and blue, Barbie and Lego, those are all inventions
that have nothing to do with the way our brains are built. That said, women's brains
differ from men's brains in some respects. And I'm here to talk
about these differences, because they actually matter
for our health. For example, women are more likely than men
to be diagnosed with an anxiety disorder or depression, not to mention headaches and migraines. But also, at the core of my research, women are more likely than men
to have Alzheimer's disease. Alzheimer's disease
is the most common cause of dementia on the planet, affecting close to six million people
in the United States alone. But almost two thirds of all those people are actually women. So for every man
suffering from Alzheimer's there are two women. So why is that overall? Is it age? Is it lifespan? What else could it be? A few years ago, I launched the Women's Brain Initiative at Weill Cornell Medicine
in New York City, exactly to answer those questions. And tonight, I'm here with some answers. So it turns out
our brains age differently, and menopause plays
a key role here for women. Now most people think of the brain
as a kind of black box, isolated from the rest of the body. But in reality, our brains
are in constant interaction with the rest of us. And perhaps surprisingly, the interactions
with the reproductive system are crucial for brain aging in women. These interactions
are mediated by our hormones. And we know that hormones differ
between the genders. Men have more testosterone,
women have more estrogens. But what really matters here is that these hormones differ
in their longevity. Men's testosterone doesn't run out
until late in life, which is a slow and pretty much
symptom-free process, of course. (Laughter) Women's estrogens, on the other hand, start fading in midlife, during menopause, which is anything but symptom-free. We associate menopause with the ovaries, but when women say
that they're having hot flashes, night sweats, insomnia,
memory lapses, depression, anxiety, those symptoms don't start in the ovaries. They start in the brain. Those are neurological symptoms. We're just not used
to thinking about them as such. So why is that? Why are our brains impacted by menopause? Well, first of all, our brains and ovaries are part
of the neuroendocrine system. As part of the system,
the brain talks to the ovaries and the ovaries talk back to the brain, every day of our lives as women. So the health of the ovaries
is linked to the health of the brain. And the other way around. At the same time, hormones like estrogen
are not only involved in reproduction, but also in brain function. And estrogen in particular, or estradiol, is really key for energy
production in the brain. At the cellular level, estrogen literally pushes neurons
to burn glucose to make energy. If your estrogen is high, your brain energy is high. When your estrogen declines though, your neurons start slowing down
and age faster. And studies have shown that this process can even lead to the formation
of amyloid plaques, or Alzheimer's plaques, which are a hallmark
of Alzheimer's disease. These effects are stronger
in specific brain regions, starting with the hypothalamus, which is in charge of regulating
body temperature. When estrogen doesn't activate
the hypothalamus correctly, the brain cannot regulate
body temperature correctly. So those hot flashes that women get, that's the hypothalamus. Then there's the brain stem,
in charge of sleep and wake. When estrogen doesn't activate
the brain stem correctly, we have trouble sleeping. Or it's the amygdala, the emotional center of the brain,
close to the hippocampus, the memory center of the brain. When estrogen levels ebb in these regions, we start getting mood swings perhaps and forget things. So this is the brain anatomy
of menopause, if you will. But let me show you what an actual
woman's brain can look like. So this is a kind of brain scan called positron emission
tomography or PET. It looks at brain energy levels. And this is what you want
your brain to look like when you're in your 40s. Really nice and bright. Now this brain belongs to a woman
who was 43 years old when she was first scanned,
before menopause. And this is the same brain
just eight years later, after menopause. If we put them side by side, I think you can easily see
how the bright yellow turned orange, almost purple. That's a 30 percent drop
in brain energy levels. Now in general, this just doesn't seem to happen
to a man of the same age. In our studies with hundreds of people, we show that middle-aged men
usually have high brain energy levels. For women, brain energy
is usually fine before menopause, but then it gradually declines
during the transition. And this was found independent of age. It didn't matter
if the women were 40, 50 or 60. What mattered most
was that they were in menopause. So of course we need
more research to confirm this, but it looks like
women's brains in midlife are more sensitive to hormonal aging than just straight up chronological aging. And this is important information to have, because so many women
can feel these changes. So many of our patients have said to me that they feel like their minds
are playing tricks on them, to put it mildly. So I really want to validate this,
because it's real. And so just to clarify, if this is you, you are not crazy. (Laughter) (Applause) Thank you. It's important. So many women have worried
that they might be losing their minds. But the truth is that your brain
might be going through a transition, or is going through a transition and needs time and support to adjust. Also, if anyone is concerned that middle-aged women
might be underperformers, I'll just quickly add
that we looked at cognitive performance, God forbid, right? (Laughter) Let's not do that. But we looked at cognitive performance, and we found absolutely no differences
between men and women before and after menopause. And other studies confirm this. So basically, we may be tired, but we are just as sharp. (Laughter) Get that out of the way. That all said, there is something else more serious
that deserves our attention. If you remember, I mentioned that estrogen declines
could potentially promote the formation of amyloid plaques,
or Alzheimer's plaques. But there's another kind of brain scan
that looks exactly at those plaques. And we used it to show
that middle-aged men hardly have any, which is great. But for women, there's quite a bit of an increase
during the transition to menopause. And I want to be really, really clear here that not all women develop the plaques, and not all women with the plaques
develop dementia. Having the plaques is a risk factor, it is not in any way a diagnosis,
especially at this stage. But still, it's quite an insight to associate Alzheimer's with menopause. We think of menopause
as belonging to middle age and Alzheimer's as belonging to old age. But in reality, many studies, including my own work, had shown that Alzheimer's disease
starts with negative changes in the brain years, if not decades,
prior to clinical symptoms. So for women, it looks like this process
starts in midlife, during menopause. Which is important information to have, because it gives us a time line
to start looking for those changes. So in terms of a time line, most women go through menopause
in their early 50s. But it can be earlier, often because of medical interventions. And the common example is a hysterectomy
and/or an oophorectomy, which is the surgical
removal of the uterus and/or the ovaries. And unfortunately, there is evidence that having the uterus
and, more so, the ovaries removed prior to menopause correlates with the higher risk
of dementia in women. And I know that this is upsetting news, and it's definitely depressing news, but we need to talk about it because most women
are not aware of this correlation, and it seems like very important
information to have. Also, no one is suggesting
that women decline these procedures if they need them. The point here is that we really need
to better understand what happens to our brains
as we go through menopause, natural or medical, and how to protect
our brains in the process. So how do we do that? How do we protect our brains? Should we take hormones? That's a fair question,
it's a good question. And the shortest possible answer right now is that hormonal therapy can be helpful to alleviate a number of symptoms,
like hot flashes, but it's not currently recommended
for dementia prevention. And many of us are working
on testing different formulations and different dosages
and different time lines, and hopefully, all this work will lead
to a change in recommendations in the future. Meanwhile, there are other things
that we can do today to support our hormones
and their effects on the brain that do not require medications but do require taking a good look
at our lifestyle. That's because the foods we eat, how much exercise we get, how much sleep we get or don't get, how much stress we have in our lives, those are all things that can actually
impact our hormones -- for better and for worse. Food, for example. There are many diets out there, but studies have shown
that the Mediterranean diet in particular is supportive of women's health. Women on this diet have a much lower risk of cognitive decline, of depression, of heart disease,
of stroke and of cancer, and they also have fewer hot flashes. What's interesting about this diet is that it's quite rich in foods
that contain estrogens in the form of phytoestrogens
or estrogens from plants that act like mild estrogens
in our bodies. Some phytoestrogens have been linked
to a possible risk of cancer, but not the ones in this diet,
which are safe. Especially from flax seeds, sesame seeds, dried apricots, legumes and a number of fruits. And for some good news, dark chocolate
contains phytoestrogens, too. So diet is one way to gain estrogens, but it's just as important to avoid things
that suppress our estrogens instead, especially stress. Stress can literally steal your estrogens, and that's because cortisol,
which is the main stress hormone, works in balance with our estrogens. So if cortisol goes up,
your estrogens go down. If cortisol goes down,
your estrogens go back up. So reducing stress is really important. It doesn't just help your day, it also helps your brain. So these are just a few things that we can do to support our brains and there are more. But the important thing here is that changing the way
we understand the female brain really changes the way
that we care for it, and the way that we frame women's health. And the more women
demand this information, the sooner we'll be able to break
the taboos around menopause, and also come up with solutions
that actually work, not just for Alzheimer's disease, but for women's brain health as a whole. Brain health is women's health. Thank you. (Applause) Thank you. Oh, thank you.
