The Ultimate Guide to the Female Brain: Neuroscientist Reveals How to Boost Mood, Energy, & Focus

27:11Welcome back. It's your buddy, Mel Robbins. And today you and I are learning from the super smart and great at math, Dr. Sarah Mackay. Dr. Mackay, let's get back into it. after kind of the primary school, when we get into puberty, what is going on in our brains when puberty hits? And why does it feel so crazy intense and confusing? Yeah. So I always like to say brains go through puberty too. Oh, I love that. Yeah. Because we think about it as being something that our body does. Yeah. But our brains are going through puberty too. So if we just, let's just focus on female puberty, but male puberty happens too.

27:57And in fact, male and female brains follow a similar trajectory, but kind of almost kick-started by sex hormones. So it doesn't matter whether it's the estrogen in the girl's brains or the testosterone in the boy's brains, they kind of follow a similar trajectory. In fact, just to kind of clarify that, we often, you might have heard this idea that girls' brains are more mature than boys' brains when they're going through the teenage years. But that's because girls on average tend to go through puberty about a year or so earlier than boys. And what we know is that brains are more likely to track along pubertal stage than chronological age.

28:38Oh. Yeah. Because you think about, you know, all of the kids that you've ever known when they start going through puberty. And you could get a boy who's going through puberty quite young, like perhaps, you know, he's six foot tall, his voice is dropped and he's got hair everywhere and he's 12. Whereas you could have a little girl who's 16 who hasn't started her periods yet. Well, his brain would perhaps be at a later stage of development than hers would be. That's so cool. Yeah, but we typically think that girls' brains are more developed than boys, but that's just because on average, girls hit puberty a year, a year earlier.

29:12No wonder middle school is so confusing because you basically may be sitting next to somebody who's got like a 19-year-old brain, but you yourself have like the 12-year-old pubertal stage in your brain. Wow, that makes a lot of sense. Yeah, so there's sort of like a biological clock sort of switches over in your brain saying, hey, it's time to start puberty. And then that sends a message down to your ovaries. And then the ovaries sort of start that monthly cycle. It takes a while for ovulation to kind of set in as we're going in through puberty. But then we start to see the ovaries releasing pubertal hormones or sex hormones, primarily estrogen and progesterone.

29:52And what we see in brains then is a lot of the growth that happens during childhood in the brain, particularly the gray matter, which is kind of the wrinkly outer kind of covering of the brain, and also some little subcortical structures. is we see that sort of start to refine and streamline. So I said, we've got all of the neurons, all the brain cells that we're ever going to have, but what we see is the connections between them kind of pruning and tuning. So we see the ones that we don't need almost being kind of pruned away and the ones that we want to be, they kind of become tuned. What ones do we not need?

30:28Well, what determines what ones stay and what ones go are the experiences that we have. So the brain kind of goes into this sort of new phase of sensitivity to experiences. Really? Yeah, very similar to what we see when a little child's like learning to talk. So the language centres of their brain go into this critical period and those little people will seek out experiences of language. They're constantly pointing and asking why and wanting to get your attention. They're constantly wanting you to converse with them because the language centres in their brain need conversation to wire up. when you're going through puberty and adolescence, a large part of that reorganisation and pruning and churning is in the social brain.

31:13And that's when we start to see those parts of the brain reorganise and shape. And what is kind of required, I think, fundamentally to go from the family nest out into the world and build a new tribe of your own is courage. And one thing that we see is the flip side of courage is bravado. So we've also got layered on top of all of the social brain development. We've also got a lot of sensation seeking, like wanting to kind of go out and have all of these experiences because that's kind of what courage to leave the family nest is kind of resulting in as well. It's like I need to go out and I need to try all these new things and I need to have these experiences and I need to do all of these things with all of these different people because the brain requires all of that.

32:01to one, rewire and reorganize to become an adult, but two, to be brave enough to become an adult. This is so cool because basically the brain has all of this programming ready to come online and it's the hormones during puberty that are like, all right, it's go time. You hate your parents. Your friends are important. You need a significant other. Your town that you grew up in sucks and it's time to go explore the world. You hate everybody and everything. You think you know it all. Yes. That's basically the wiring in the brain. 100%. 100%. And is there a difference between the way that puberty for the male brain brings that online or the way that boys tend to respond to that change versus the way that the puberty hormones and all of that coming up and lighting up in the brain is different for girls?

32:54I mean, we do start to see some of the sex differences that we see in adulthood do start to emerge around puberty. And we can talk a little bit about perhaps mental health in a moment. But in terms of that developmental trajectory from a child's brain to an adult's brain, we all go through that. But the experiences that we're kind of seeking out, the same types of experiences, and often they're with each other, of course, we see these behaviours sometimes play out differently. And part of that may be, particularly in young males, testosterone does drive a tendency towards some types of behaviours.

33:35That sensation-seeking in particular, which looks to adults like really dumb decision-making or risky behaviour. Girls might be less likely to do the same kinds of reckless activities, but there are some things that girls can do that might not necessarily be to their benefit. We might need to encourage them a little bit more, even if it's just to do something that might feel to them risky, like, I don't know, putting your hand up in the classroom and asking a crazy question. You know, there's different types of risks that people take depending on what kind of peer approval they're going to be getting.

34:08So it's very hard to separate out the risk-taking behavior there from that social aspect of peer approval. What I find fascinating is just that this is all in the brain ready to activate. And you can get very frustrated if you're a parent or if you're the older sibling. And we roll our eyes at those years without this recognition that actually this is part of what the brain goes through that is developmentally accurate and normal for somebody that age. And you and I are going to dig deeper into this topic of the female brain because your insights, Dr. Mackay, are incredible. So give me a second.

34:52I want to pick my job off the floor. I want to have this kind of marinate. This is kind of that top-down thing you were talking about. And let's take a break. When we come back, you and I are digging into PMS. So stay with us. And while you're listening to our amazing sponsors, make sure you share this with everybody in your life. The women in your life need to understand the science of the female brain. The men in your life need to understand the science of the female brain so that they can understand and support you. We all need to understand this. So don't go anywhere. Dr. McKay and I will be waiting for you after this short break.

35:37Welcome back. It's your buddy Mel Robbins. And today you and I are learning all about the female brain and the three factors that shape the brain and the brain development with Dr. Sarah McKay. So Dr. McKay, let's keep going. Why are teenage girls more prone to anxiety and depression? All through childhood, if we were to have diagnosed anxiety and depression, boys and girls are pretty similar. And we do start to see a divergence of puberty. Boys, of course, can experience anxiety and, of course, experience depression. But we do see a higher incidence in girls. And I think then the next question to ask is, well, what causes something like depression?

36:17Or what causes something like anxiety? and I always say depression comes in many shades of blue and there's as many shades of blue as there are causes of those shades of blue and this is when I like to get back to my basic model of we've got this brain sort of sitting in a universe, right? It's sitting in our body so there's all of this information that it's receiving from our body. You know, everything from hormones and we tend to just blame the hormones but there's a lot going on in our biological bodies that we can do to take care of our brains, sleep, exercise, food, all of the things that we as mothers tell us to do.

36:57So we've got a bottom-up biology, which we could tweak and shape and shift to influence depression outcomes. We've got a lot of outside influences, you know, education, family. Do you have stable, loving relationships? So we've got all of that in the outside world. And if we, you know, we're breaking friendships or we're lonely or we're stressed by social media, you know, our brain is making meaning of that information, the outside in, as well as the bottom up. And then we've got top down because we're humans. So we're constantly telling ourselves stories and making meaning of what's going on.

37:32So we've perhaps we're ruminating or perhaps we haven't learned to reframe, you know, into a more healthier way of thinking. And all of these pieces of information from the bottom up, the outside in, the top down, Our brain is making meaning of all of them. And there's going to be differences there between boys and girls. And by meaning, you basically mean the brain is changing the way it's wired, creating new connections, ending old connections, locking in beliefs based on this kind of three-part framework of the bottom up, which is like the physical environment that the body's in, the outside world.

38:10And you use the word flooded, which I freaking love because that's how it feels. It comes in through our senses, through our eyes and our ears. Yes, and then the top down, which is the things that you're saying to yourself as you're trying to make sense of all of this, all of which impacts the way your development operates and develops. And if something's not quite right, and many, many, many, many of those different kind of data inputs, any one of them could influence mood and depression and anxiety. So as I say, there's many shades of blue. So it could be someone's more depressed because maybe a girl is what we might say hormone sensitive.

38:47So we like to talk about hormones as being the cause for depression, the cause for anxiety. And that's when we start giving the girls that message from puberty and it's really damaging. But we do know that there are some girls and women who are what we might call hormone sensitive. It's not like they've got bigger highs and lower lows of hormones. it's that there's something about their body which makes them a little bit more sensitive or vulnerable to those shifts. Dr. Mackay, I should say that one of the reasons why I'm jumping on this term, hormone sensitivity, is because in the past, I have absolutely blamed bad period cramps, menopausal symptoms, all kinds of stuff on just being sensitive to hormones.

39:29And what I'm learning from you and what I've learned as the mother to two daughters in their 20s that have had issues with hormones is that we reach for the label, but you're teaching us that this is much more complicated than just a label. Because if you think about the three factors, there are things within your control, whether you're talking about, are you eating healthy? Are you getting sleep? Are you not drinking alcohol? Are you moving your body? Are you connected to positive friends? Look at some of these things in your control. Get a good night's sleep for a couple of weeks. Stop drinking alcohol.

40:04Reconnect with your friends. Take better care of yourself and see if you're able to manage the ups and downs of life and your hormones a little bit better. I love that. And I love that you're making us smarter about the things that we can do. You mentioned sleep. Can you explain? You just kind of casually was like, well, sleep is the number one thing. Why is sleep and getting more sleep, other than social connection for the male and female brain, why is sleep so critical for the female brain? And I think for the brain, for babies, teenagers, everyone, if we miss one night's sleep, everything is harder.

40:41It is so much harder to do all of the other things that we need to do, you know, both on our to-do list, but also to look after ourselves. So we all know how bad we feel after one night's sleep being disrupted. What are the repercussions? Like what's happening when you sleep that's important for your brain health? So there's a whole host of different things that kind of go on. So we know that we, that's when our memories get consolidated during the day. Our brain's kind of sifting through and reshaping and kind of moving our memories and our experiences and what we've learned from short-term storage into long-term storage.

41:18And we know that, again, poor sleep is a risk factor for poor mental health, for poor brain health increases your risk for almost every health condition. You know, people who consistently have bad sleep have high rates of mortality. So, you know, it permeates every aspect of kind of our physiology and our psychology. Makes sense. One of the things that I read in your book is that a woman gets her period about 450 times in her lifetime. And yet, you know, you still don't quite understand how to deal with the fluctuating moods and the brain fog and all the other mental and emotional symptoms of PMS.

41:59What is happening in the female brain when you're going through your menstrual cycle? Oh gosh, this is like we could do hours and hours on this one, Mel. So we have this brain and ovarian conversation that sort of starts at puberty and it goes maybe 450 times through your life, depending on how many pregnancies you have. And if you're on the pill, you can flatline it until menopause in the last couple of years. There are these epic studies that have been done by women scientists who have started experimenting on themselves. They're like the Marie Curie of neuroscience. And so they are doing all, instead of waiting around for someone else to do the study, they're like, let's just do it on ourselves.

42:41So there's a couple of scientists who have said, right, I'm going to put myself in a brain scan every day to see what happens across the course of my menstrual cycle. And they're being very meticulous and very careful in taking blood samples so they know exactly which day they're on, what their different hormone levels are doing, and then they'll lie on the brain scanner and just lie there for a couple of hours. And what you can do is just look to see how the brain is just reacting when you're lying there doing nothing. So we see as you go into ovulation, when your estrogen kind of peaks and a couple of days later, because the brain networks take a kind of, they kind of lag a little bit behind the hormone because the way the hormone works on the cell as it interacts with your chromosomes and your DNA, it's not like this immediate like millisecond response takes a couple of days.

43:29We see that those brain networks become far more kind of integrated and specialised when there's high estrogen and then there's estrogen kind of drops off and then progesterone starts to rise in the days before your period, different brain networks sort of start to interact more with each other. And for some women, that just might feel like nothing. But for other women, it might feel like an absolute emotional roller coaster, right? So the ebb and flow in everyone is going to be the same. The levels of hormones in everyone are going to be the same. But for some reason in some people, that can feel like a roller coaster.

44:06Others, it barely feels like a gentle ripple. What happens, what does the pill do to your brain? Like what's happening in your brain? So the same scientists that have learned in the brain scanner every day over the course of the month, they gave the study a very cute name. They called it 28andMe. And then they did a study of the oral contraceptive pill and called it 28andOC, the oral contraceptive. Very epic science that's being done by these women. And then they went on the pill. And so we know that when you go on the oral contraceptive pill, which is an excellent form of contraception, that it flatlines your natural levels of hormones.

44:43And then you kind of get this high level of hormones from the pill. And it kind of depends on which formulation that you're taking. Does it hurt your brain? No. What we would see if we're looking at these networks is that the networks then flatline. Instead of ebbing and flowing with your natural levels of hormones, your natural levels of hormones are flat, the levels of hormones from the pill are flat, and so your brainwaves just kind of go flat. And for some women, that might feel like stable mood. So we know some women go on the pill and they find it stabilizes their mood, particularly women that have extreme PMS or the extreme form of that PMDD.

45:22Some women find that going on the pill makes their hormones, stabilizes their hormones and makes their emotions feel stable. Other women might feel it, maybe their emotions are flattened. Because we've all got very, very different sort of responses and sensitivities to how hormones are interacting with our brain. And there does appear to be sort of a subset of women who are hormone sensitive. And by hormone sensitive, what exactly do you mean as a neuroscientist? Yeah. So we don't know. I mean, we're still kind of at the very, very early stages of starting to understand what is going on in a brain that's responding to hormones, let alone what is going on in the brains of all these different people who have different types of experiences and different types of emotions.

46:08And it's particularly emotions that we're interested in across the course of the menstrual cycle. So there are plenty of women who will say, yeah, look, I have PMS symptoms. I experience, I feel angry and irritable and grumpy and weepy, et cetera, before their period. There are also a subset of women who might feel particularly energised and maybe even a little bit frisky with the onloading of oestrogen, so around ovulation. We've all got these different sorts of, appears to be this different kind of baseline sensitivity to these hormone fluctuations. And it's not that the levels of hormones are any different.

46:47There's something in the way that we're responding to those hormones that are changing, but we don't really kind of know what it is. We do see these hints back to girls who go through early puberty and perhaps even girls have experienced early childhood trauma. I can't believe you just said that because I just wrote down on this piece of paper, I wonder if hormone sensitivity is correlated to adverse childhood experiences or sexual abuse. It is. It is? And that's not an inevitable. If you experience that, you will be hormone sensitive or if you are hormone sensitive, it is only due to that. But we see a tendency.

47:24And so there are some clinicians and researchers, particularly those working in the menopause space, who are starting to recognize the sensitivity and then kind of going all the way back to early childhood and asking women, well, you're in perimenopause, you've got depression, or you had postnatal depression, what was your early childhood like? It's not a direct causation in everyone all of the time. It's a risk factor. It is a risk factor. So we're starting to see that kind of emerge. Well, it makes sense because what you're teaching us is that you basically have taught us that you have all neurons in place, right?

48:02That 80 % of the brain is developed by the age of five. That every experience both in your body and flooding you from the outside and the way that you process it from the top down fashions the way that the brain is shaped, how it operates, what synapses come on, which ones disconnect. And so if you have adverse experiences and those adverse experiences flood you with hormones or neurochemicals, something is happening with the receptors in your body. And so it would make perfect logical sense that that would be a risk factor in terms of the way that your body processes those exact same hormones later in life or those neurochemicals.

48:49Yep, yep. I mean, it's logical. And it kind of becomes cumulative as well. And that's why one researcher I spoke to says puberty is like an emotional blueprint for how we're going to respond to reproductive experiences later in life. Because it's almost sort of setting that in place. So particularly, I think, parents or, you know, caring adults around girls who are early, you know, going through puberty early, we know that we can provide those kind of protective experiences and do the best we can to help those girls go through that kind of, you know, entering puberty before their friends, that experience kind of helping them through that.

49:24And there have been studies done like kind of looking at those as interventions. And so it's like a really important time to kind of intervene for one of a better way because we will see, you know, the kind of the repercussions. And one of the risk factors for depression at any point in life is have you had a previous experience of depression? How does pregnancy and motherhood change the brain? Oh, one of my favorite topics, Mel. I've written a whole book on this. So an overarching statement I would make would be that pregnancy prepares the brain and mind for motherhood. And some studies have been done, and this was pretty much nothing was published on how women's brains changed during pregnancy and motherhood until sort of around 2017.

50:11So it was quite late. We knew what was happening in animals. There was a group in Spain, and again, there's some really great researchers out there working in women's health and they're all women and it's because they're the ones asking the questions so it was back in 2009 these kind of three women were having this conversation and said well what would happen if we became pregnant let's go look at the research there is no research let's do the study ourselves let's get pregnant and scan our own brains and try and find some friends to join in and so that has like this field of sort of the maternal brain or the neurobiology of matricence, you could call it, has sort of exploded.

50:51And so they've scanned women's brains before their first pregnancy and after their first pregnancy. And more recently, another epic study done by a woman who's experimented on herself, scanned her brain all the way through pregnancy. And we see this enormous structural reorganization and rewiring of the brain through the course of a pregnancy. What happens? Oh my God, you're literally like making another human being. So is the brain like figuring out how to talk to the mechanics of the baby? Yeah, yeah. So the biggest, so they see, and this, when I first, the way I don't like to say this because people immediately think that something has gone wrong, but we say we see a 4 % volume loss in the brain during the course of a pregnancy.

51:33But we also see this in teenagers' brains and adolescent brains, right? They get slightly thinner as the brain is streamlining and refining and pruning and tuning its synapses. And we see this throughout the brain during the course, particularly of a first pregnancy. And it's primarily in those parts of the brain which are involved in social cognition. What does that mean? What is someone else thinking? What is someone else feeling? How do I read the needs of somebody else? And how do I deploy the right behaviors to look after them? Meaning you care more about it? Who was the other person that you're going to be looking after at the end of a pregnancy?

52:07It's the little baby. Yes. So your brain is being reorganized to deploy the right types of behaviors to look after your baby. And that sounds very kind of like I'm describing what happens in an animal, but we've got a whole lot of data from many other animals in the mammalian kingdom looking to see how their brains reshape and reorganize so they deploy the right types of maternal behaviors. Well, if you don't, the baby's going to die. Well, exactly. The same thing happens to us. So we become very, very tuned in. This new baby comes into the world and you can't really sort of think about anything else.

52:42all of your attention, particularly with your first baby, is solely focused in on that little baby. You almost can't think of anything else. No wonder you can't remember about the bananas or the keys or your husband's lunch. How horrible the labor was. Yeah. What is happening with your brain where you forget the pain of? I think mother nature has made that a thing so that we just keep on having more babies. I I remember my first childbirth and being really annoyed with my sister because she is one of those people that said it was good pain. It wasn't that bad. And I remember a few hours in when I started screaming for the epidural, she said it was going to be good pain and it's not.

53:24It really hurts. And then I remember the first contraction with my second son. I was like, oh, that's right. It's all coming back to me now. Second birth was easier. Actually, the second time around motherhood is a whole lot easier because your brain has already gone through that process of reorganizing, reshaping, and then learning how to become a mother. So what happens when the baby's born, your brain has gone into another sensitive phase of learning by experience because of all of the pregnancy hormones you've experienced. It's a little bit like puberty. And that is why sometimes we talk about matrescence is like adolescence.

54:04It's this journey of becoming a mother. So through pregnancy, your brain is reshaping and reorganizing so you can become a mother. And it makes that learning curve perhaps a little less steep. You still need to figure your baby out and learn how to take care of it, but your brain is kind of primed to react and respond and almost to focus solely in on that new little baby and take care of it. Is there anything that's happening in the male brain while the female brain is undergoing all this? Yeah. So the woman in Spain, this is the first study that was ever done looking at this. Because they were clever and smart women, they said, let's look at the fathers.

54:43So these were heterosexual couples. Let's look at the fathers of these babies as well. Scan their brains before and after their partner's pregnancy and look to see if their brains change. And in comparison to the mother's brains, their brains did not change. At all? At all. However, if you just look just at the males and you kind of increase the, like get more men involved who have just had babies, their partners have just had babies, and just scan their brains, we do see some tiny little changes, not at all in comparison to the women, but tiny changes within those men's brains, which are based on how involved they are with childcare.

55:24And, you know, some men are there for the act of conception only, some fathers, and are never seen again, and other fathers are the primary caregiver. So you would expect if a dad is the primary caregiver, his brain is going to change a whole lot more than the dad that was just there for conception only. So let's talk about menopause, because I would imagine that - We're not going to talk about baby brain and forgetfulness? Oh, sure. I forgot. I'm not even pregnant, for crying out loud. Only because that's - Wait a minute, why is there forgetfulness when you have a baby? Well, lots of people talk about like mummy brain and baby brain and you become forgetful.

55:59Because we're exhausted. Well, yeah. So four out of five women during pregnancy and early motherhood will say yes. And I didn't experience it, which is why I wanted to write the book, because I thought I didn't know it was a thing. Okay. It wasn't a story I'd ever heard and I didn't experience it. And I was like, I wonder if there's something in that. Is there a neurological thing? Well, we know our brain is completely reorganized to attend and focus on the baby. and memory depends on attention, right? So what information you take in and what you filter out. And so when you're entirely focused in on your new baby, you're not going to remember all of the other things.

56:37But because we have been told that if you've got a female brain, you add some hormones in and you add motherhood to the mix, you're kind of dysfunctional and you're on the decline and all of the potential things that can go wrong. And of course, we could experience postnatal depression. Of course, we could experience postnatal anxiety, but we know from the research that women who are experiencing less overall wellbeing over that amount of time, have less social support. I mean, no one's getting sleep, right? They are much more likely to describe their experience as what we would call baby brain than women who are well, socially supported, don't have postnatal depression, are kind of doing okay.

57:20So it's not women's brains that are letting them down. It's the social support that they're not receiving to parent that is letting them down. But we have persisted with this story that there's something neurologically wrong with us when we become mothers. So we shouldn't call it that anymore, right? No, it's not. Because that's actually the wrong term. Because if you call it baby brain, you're basically blaming your brain. And what you're saying is, no, no, no. First of all, your brain's working right because any energy you have, your brain is being ordered to focus on this human being whose survival is dependent on you.

57:58So the fact that you are focused on the caregiving is what you're designed to do. It's working correctly. The problem isn't baby brain. The problem is you don't have support. Yeah, and you would have heard of like the emotional labor or the cognitive load of motherhood or just being a woman and having to do all of the things. and people love talking about a super mom, right? Because she can kind of do everything. Give it to her. She can do it all. And if she drops a ball or something goes wrong, well, it's okay because she can just blame her baby brain. And then everyone goes, oh, well, it's her brain's fault.

58:30Yeah, you can still cook dinner and do the night feeding and I'm going to sleep for 12 hours while you do all that and it's your baby brain. You'll be fine in nine months. It's not her brain. And we've got this amazing research looking again, like I talked earlier about imaging brain networks and we look at mothers' brains and their brains are more flexible and efficient and responsive. Wow. But we persist on always telling the dysfunctional story instead of looking at the strengths. And what is the best intervention? Is it getting support in sleep? Yeah. Is it the second you start saying, I've got baby brain, say, no, look where you need support.

59:05Yeah, well, I mean, it shouldn't have to be up to the mom to be told to look for support, should it? That's true. Yeah. That's true. So let's talk about menopause because another period in a woman's life where we tend to talk about brain fog is when we're going through menopause. What is happening to the female brain when we dry up like a raisin? Well, that brain ovarian conversation that's been going on, we've talked about puberty, we've talked about menstrual cycle, we've talked about pregnancy. see, it kind of starts to falter a little bit and it's been, you know, kind of going on really nicely for many years.

59:46And then what happens is menopause actually starts in our ovaries, right? We run out of eggs. Ovaries start to give up. Sometimes, you know, they ovulate. Sometimes they don't. The brain is up there listening, going, you didn't ovulate. Ovulate. The ovaries go, okay. There's huge amounts of estrogen. The brain goes, not that much. The ovaries go, okay, sorry. So, you know, we kind of get this rollercoastering and that's what we would call perimenopause. And then our brain is starting to respond to that massive rollercoastering. We know kind of what happens with our bodies. We get irregular periods.

1:00:20We can get really heavy periods. We can get none. And then they come back and it lasts for two weeks and all of the things that are going on. And our brain is kind of in the middle trying to adapt and respond and flex and kind of make the most of this sort of situation that it's in. Brain fog is one of the words that we use, this kind of umbrella word that we would use to describe this kind of constellation of symptoms, perhaps not dissimilar to baby brain again, but this time there's probably a little bit more of a biological cause behind it. But we're not sure exactly what is this kind of nice, neat biological pathway.

1:00:59And I love a biological mechanism. We know that estrogen is kind of rollercoastering and then after menopause it's flatlining. We're pretty sure we know how the brain causes hot flashes and how that estrogen is involved there. How does estrogen cause hot flashes in the brain? So we've got the hypothalamus, that part of the brain that's receiving all the data from our body. So it's also, it regulates our body temperature and the thermostat in the hypothalamus is almost set by estrogen for some reason. The brain evolved to have that thermostat to be set by estrogen. When the estrogen starts doing its crazy thing, the thermostat gets really narrow.

1:01:37So the top goes, so it gets much narrower. So your body temperature only needs to rise a tiny bit to kind of hit the upper level. And your brain goes, it's hot in here, it's hot in here. And it sends two signals out to your body to cool down. Physiological signals, like you go really red and you sweat. Because it's in an emergency situation. and then also for you to go, oh, I'm hot and therefore I will behave in a way to calm myself down or take my jumper off. When you are asleep at night, your body's like doing the whole sweating thing but sometimes you've got the covers on but you're asleep and so then your brain needs to wake you up.

1:02:14And some women describe it in my experience, being 50, it feels a little bit like you've had a fright, like you wake up and you've gone, ugh. It's not like just waking up normally. You can almost feel the adrenaline going through your body because your brain has had to wake you up. Wake you up to behave in a way to also cool you down because the sweating wasn't quite doing enough. Yes. By that point, it's like a puddle on my side of the bed. Yes. And then I'm like, how was I asleep when these sheets are so wet? And why am I so warm? Yes. Yeah, and we know a couple of things. We know if we put estrogen back in with menopause hormone therapy or HRT, whatever you're going to call it, We know that that kind of reset that thermostat.

1:02:56And we know that that's putting the estrogen back in as one of the best treatments for vasomotor symptoms. What we're seeing and some of the ideas are that body temperature and sleep are really intimately entwined. And every menopausal woman knows that, right? You might not know that if you're a young teenage fella, right? You might not have figured that out. But we all know that about 70 % of the hot flashes that we have overnight, and so studies have found about 70 % of the hot flashes will wake us up. You might not remember waking up, but your sleep's being disrupted. But even if you're not waking up, that nice sort of, you know, those sleep studies that you see where you've gone to deep sleep and then up into REM and down again, that just gets all, that nice neat architecture just gets disrupted.

1:03:42So if that happened for one night, you would feel a bit rubbish. If that happens for a week and a month and for years on end, well, what's the inevitable consequence of sleep disruption? Memory. You just feel terrible. You're more vulnerable to depression. You're more vulnerable to memory problems. That's perhaps one of the reasons why we are seeing problems with what we would call brain fog. Well, Dr. Mackay, here's what I'm getting from you. Are you ready? What I love about the way that you're teaching us and the rigor with which you're explaining the research and the science is that for somebody like me, who's just a person going through this, and then I go, I blame it on menopause.

1:04:25I blame it on my hormones. I blame it on estrogen. You basically are saying that's part of the issue. However, if you look at the female brain and you look at what's happening when your body is going from this bottom up biological change and the hormones are changing, your brain is responding. And one of the big things that happens is it's interrupting your sleep because you're basically overcooking yourself as you're sleeping. And because that's happening over and over and over again, whether or not you remember waking up, the brain fog isn't quote necessarily because you're lacking estrogen.

1:05:05The brain fog is what's accumulating. It's like a domino effect. And with that constant sympathetic activation multiple times a night, that's going to have a couple of different consequences. We see consequences for cardiovascular health. And the same we would see with sleep apnea. If someone like their sympathetic activation goes off to wake them up so they start breathing again, and we know that that's really bad for cardiovascular health and cardiovascular health is not great. Bad cardiovascular health means bad brain health. So we've got that kind of consequence. And we also see with repeated sympathetic activation for perhaps no reason that we, you know, it's not like something out there was giving us a fright, but repeated sympathetic activation makes you more hypervigilant.

1:05:55And when you're more hypervigilant on top of sleep deprivation, you're much more vulnerable to anxiety. And it's almost like your sympathetic nervous system has been activated multiple, multiple, multiple times. And so it becomes more hypervigilant. So you feel anxious, even though there's not necessarily anything that has changed a lot. So there's a whole lot of different consequences there. So that could kind of feed in to the brain fog. So how can women protect or strengthen their cognitive health as they age? Yeah, so there's some pretty clear data which has come out. I believe I wrote it down earlier.

1:06:31So there's some pretty clear data that has come out and the sort of the entire pool of data that we've gathered from all over the world looking at Alzheimer's disease risk is kind of analysed and put together every year by this Lancet Commission on Alzheimer's Disease and they put this information out. And what they're saying currently, based on the data to date, is about 45 % of cases of dementia and Alzheimer's disease could be prevented by intervening with various types of lifestyle factors. And this is like for males and females. So that's quite high, right? 55 % are probably biological things we can't necessarily do much about.

1:07:09Okay, but 45 %? Yeah. And so 5 % of that is early childhood education. And that's quite a lot, right? So the more years you stay in education and the more enriched childhood experiences you have, the more protected you are. And that's perhaps where we see some of that gender inequality in some parts of the world. And that could almost explain that incidence, that inflow, differing between males and females in countries where there's the gender inequality in childhood. And bearing in mind, we could be looking at people in their 90s, so we're having to look at what their lives were like 90, 80 years ago.

1:07:45Midlife is really interesting because we know there is this factor which is responsible for about 7 % of cases of Alzheimer's globally, and no one talks about it because it's deeply unsexy, and it is hearing loss. Wait, what? Hearing loss? Yeah. Untreated hearing loss in midlife. Huh. So we know the causes of the hearing loss, like listening to too loud music and industrial hearing loss, et cetera, and then perhaps you're just getting older. But what is it about hearing loss that is causing Alzheimer's disease? And we think partly it's around, well, what happens when someone loses their hearing?

1:08:22They can't kind of interact with other people. They withdraw socially. They might withdraw from work. They kind of shut down. And remember, like, we're constantly receiving information about the world through our senses, through our eyes and our ears, primarily as humans. And so it's just kind of cutting off one of these kind of sensory inputs that our brain is receiving. So that's, and no one's talking about that, because it's not very, like, kind of fun and sexy to say, you know, go and get a hearing aid. It makes sense. There are people that are out there saying that, but I don't think they're getting the kind of attention they deserve.

1:08:55Dr. McKay, what is the next frontier of research in women's brain health that excites you the most? Well, now women's, I mean, I always say women's brain health is no longer a niche. And so I'm looking forward to seeing what, you know, comes out of that. Like parent numbers, data, it's very nerdy, but I think that that's what's going to give us the answers. Well, you are proving that women are, in fact, good at math and science. If you could give the person listening one science-backed recommendation for caring for the female brain, what would it be? What's the most important thing? Besides sleep, you can get that sorted.

1:09:39You're halfway there. I think when I first sort of started moving into women's brain health research, you know, I've been doing neuroscience for a long time. I thought it was all going to be about hormones, hormones, hormones, hormones. That was going to be what it's about. But I think it doesn't matter at which life stage you are considering, whether you're looking at infancy, childhood. We talked about girls going through puberty. We know what teenagers need, new mothers. You know, as we are aging, it's really about other people. And we have these, our brain is like a social organ. and what it needs at every age and every life stage is social interactions with other people.

1:10:17And I think we tend to forget how important relationships are as determinants of health. And we have that real tendency, as I said, from puberty, to just blame the hormones and to only look about, look for what's going wrong and not looking at how, I think, social infrastructure or architecture can protect and promote that resilience and that adaptability. So I think other people are the key to a healthy brain. You know, one of the things that I think is also damaging that is out in the zeitgeist is that women are better at relationships than men and women are more social than men and men do not have support structures.

1:11:01And while that may be true, the presumption is it's because they're not capable of creating it. And is that recommendation also true of the male brain? Yeah, that's true for humans. I mean, I've got teenage sons and I've got to feel like I'll cry thinking about them being sad and lonely. Yeah. So, yeah, that's just what humans need. But I think we do tend to, particularly with girls and women, zoom in on the hormones. And we can't necessarily always do a lot about that. and that kind of removes the agency or the ability to kind of look beyond that to other people. And we just have so much research that often the strongest determinant of health outcome is other people.

1:11:46Dr. McKay, what's your parting words? I was thinking about this because all of the work that I talk about in all my books and teach and I write about, that's not research that I've done. It is me talking about the work that other researchers have done because, you know, I don't work as an academic neuroscientist anymore. I'm a science communicator. And I just have so much to thank all of those researchers out there doing the work. Like so many of them, like some of them are like women of steel who are asking these hard questions, battling for the funding and then seeking the answers. And it takes a really long time to do good science well.

1:12:29It takes time and money and you have to be meticulous. And sometimes it's nuanced and sometimes it's mixed and sometimes the answer is still we don't know. And so I think my parting word is I just want to like acknowledge them and thank them and cheerlead them because I couldn't do what I do. I'm just talking about the work that they've done. So, yeah, my parting word to them is just to say thank you. I love that. I'm going to say thank you too. And is there any final thing you want to say to the person who has just spent all this time learning from you that you want them to know about their brain or the future that's possible for them?

1:13:06I think we have been told for centuries the story that women's brains are unstable and chaotic and dysfunctional and other than male. And our brains are actually like resilient and adaptable. And that's not just me saying that because it's a nice thing to say. It's really and truly what the neuroscience is showing. And so I know that there's gaps. I know that, you know, not everyone has, you know, the best life experiences, but the research is sort of showing us that there is a really good news story. And if we look for the strengths and we also tell ourselves the good stories, then we may be able to influence some more positive health outcomes along the way.

1:13:55Amazing. Thank you for being here. Thank you for inviting me. I learned so much from you today. No, seriously. My brain feels like popcorn is popping all over the place because you challenged me to think about this topic completely differently. it's very empowering to think that between your ears and on top of your neck is this incredible organ that is constantly adapting and has this crazy intelligent design and when you understand the fact that it's only just responding to the input physically and from the world yeah you actually hand us the keys to think more critically about how to add positive input, how to stop buying the lies that we're being told about the way that women are or girls are or men are or boys are and understand that it can always adapt and change.

1:14:52And that's a very positive and encouraging thing. I just feel so much smarter. And I really appreciate you hopping on a plane, you coming all this way, you pouring into us. Thank you for the work that you're doing. This has been amazing. And I also want to thank you. Thank you for taking the time to listen to something that is going to help you understand your mind and unlock the power of it. And in case no one else tells you today, I wanted to be sure to tell you that I love you and I believe in you. And I believe in your ability to not only create a better life, but with a better understanding of the way that your mind works, I think you can unlock the power of it.

1:15:33And I can't wait to see what you do with everything that you learned today. So thanks for being here. And I will see you in the very next episode. I'll be waiting to welcome you in the moment you hit play. I'll see you there.

1:15:49We're going to, this is going to be fantastic. Thanks. Of course. Thanks for having me. Of course. Thanks for coming to my 50th birthday party tour. I came to see my friend Mal. Yes, you did. Yes, you did. So, yeah, you're part of the birthday party. Well, thank you. When is your birthday in January? It was in January 7th. 7th. That's my mother's birthday. When was it? My husband is the 6th. Oh, really? Yes. Lots of Capricorns. Happy 50th. Yeah, thanks very much. Is that what you're doing? We're leaning into it, right? Okay. Wow. Holy cow. I need to pick my jaw up off the floor. Great job. How do you feel?

1:16:22That was fun. Good. That was awesome. You were awesome. Everybody tell it. Everybody.

1:16:36Oh, and one more thing. And no, this is not a blooper. This is the legal language. You know, what the lawyers write and what I need to read to you. This podcast is presented solely for educational and entertainment purposes. I'm just your friend. I am not a licensed therapist. and this podcast is not intended as a substitute for the advice of a physician, professional coach, psychotherapist, or other qualified professional. Got it? Good. I'll see you in the next episode. Stitcher.