I am excited to connect with one of my favorite neuroscience experts today! Louisa Nicola is at the intersection of neuroscience and athleticism. She helps to bring a fresh understanding of what it takes to achieve peak performance through science-based tools and methods. She is also the host of The Neuro Experience podcast, which focuses on brain health, neuroscience, longevity, and athletics.
Louisa knows how to take complicated subjects related to brain physiology and hormones and explain them so that people can fully understand and appreciate them. In this episode, she and I dive into her background. We speak about her three pillars for peak performance, alcohol, and how sleep impacts the glymphatic system. We get into strategies for better sleep, the perimenopausal brain, how chronobiology impacts sleep, how to address jet lag, and how exercise improves brain performance and health. We also talk about the best foods and supplements for brain health and how creatine improves performance.
I hope you enjoy listening to today’s conversation as much as I did recording it!
IN THIS EPISODE YOU WILL LEARN:
How an accident shifted the trajectory of Louisa’s life.
Louisa unpacks the various stages of sleep and explains why sleep is so important.
How sleep impacts the glymphatic system.
Some common characteristics of perimenopause.
Some simple ways to aid the penetration of naturally secreted hormones into the brain.
How blood pressure fluctuations impact the brain.
What is jet lag, and how can we combat it?
How does alcohol affect the brain?
Louisa explains cardiac remodeling.
The value of different types of exercise for brain health.
The difference between physical activity and exercise.
How our food choices impact our brain health.
How to mitigate the effects of traumatic brain injuries.
How does creatine monohydrate improve brain performance?
“Sleep is the most underrated high-performance tool that we have.”
-Louisa Nicola
Connect with Cynthia Thurlow
Check out Cynthia’s website
Connect with Louisa Nicola
Transcript:
Cynthia Thurlow: Well, Louisa, I've been so looking forward to this conversation. Welcome to Everyday Wellness.
Louisa Nicola: I'm so excited to be here and likewise, I've been really looking forward to it.
Cynthia Thurlow: Yeah. Share with the listeners a bit about your background because I know that you started as a competitive triathlete. You were this incredible nationally, internationally recognized athlete, and then you had an accident and the trajectory of your life really shifted.
Louisa Nicola: Yeah, no, that's correct. Back in my younger days, I always say, that was 40 pounds ago, I was a triathlete and it was my first love. At the time, I was doing an exercise physiology degree, so that's what I thought I was going to do. And I just loved the body. Four weeks prior to going to Beijing, I had an accident. I was hit by a car and I was hospitalized and had a few broken bones, which I had to get fixed up. Because of that, I had to forfeit my title. During that recovery phase, which I was first told, you may not walk again, then I was told, okay, we'll get you up and running, but you're going to be in a critical condition. I never let that get me down. I spent a lot of time, obviously, in rehab and in hospital, got myself back up, and requalified for the Championship Series in Auckland.
I ended up qualifying, obviously, and then coming 13th. That's when I really understood that you don't have limitations. The only limitations are what is within your mind and in your brain. Cynthia, so I had done exercise physiology. I'd gone through and done a master's degree. Funnily enough, my master's degree was in mathematical modeling. So, it was a pure mathematics degree. During that, I was writing about neurons firing because I fell in love with the brain. That then led into medicine and neurophysiology, which is rightfully so what I am today and what I do today. But I wanted to marry the two. I was an athlete and I used to look out and think to myself, okay, there're amazing tennis players out there are amazing footballers and soccer players, why isn't anybody looking after their brain? That's when I realized that there was a niche for Neuro Athletics, which is my company. I kind of married the two elite performance and neurology put together and that's where we live now, at the intersection of those two.
Cynthia Thurlow: Well, I think it's such a beautiful combination of two areas of interest of yours, and one of the things I love about you and your podcast and the information you share is that you take complicated subjects, but you put it in such a way that people can fully understand and appreciate brain physiology, hormones, all of these things that come together. You speak quite a bit about these pillars of brain health. I think starting from a place talking about sleep is of particular interest. Most of my listeners are north of 35 years old and sleep in many ways can suddenly become elusive. But let's unpack the physiology of sleep and better explain things. Because, as an example, I was speaking to a patient earlier this morning who used to get by on 3 to 4 hours a night of sleep, and 12 years later she's wondering why she's having some of these issues of metabolic health, insulin sensitivity and trying to explain to her that the research as I know it is we make our brains in our 60s, 70s and beyond in middle age. If we're not taking care of ourselves, it can have a profound net impact on the way that our brains age and the degree of inflammation we experience.
Louisa Nicola: Yeah, you're completely right. We do make our brains, our 60, 70-year-old brains in our 30s and in our 40s. So, that's quite scary, right? Because when you look at the human brain, it starts to atrophy. Atrophy just means a decrease in cell size and it starts to decrease in cell size at the age of 30. The wonderful thing is it doesn't have to be at an alarming rate. We can slow the progression of this atrophy through various lifestyle interventions. The three pillars that I speak about, which slow the progression of this atrophy is sleep, exercise, and nutrition. We'll go into all of them, obviously, starting with sleep. But I have to tell you that if you aren't in your 30s, and if you aren't looking after your brain in these ways and taking these three pillars into place, you will be up for a challenge, and one thing that was really prominent to me, I was just flying around the world, literally.
I went to Australia, and then I went to LA, Sacramento, Vegas. I was on a little podcast tour myself. It just wreaked havoc on my circadian rhythm, on my hormones. Sorry to all the men listening, but when you get a disruption in your circadian rhythm, the menstrual cycle gets put on hold. For somebody who tracks it avidly like me at every day, it then becomes like you get it a week later. So, many things are just disrupted due to circadian shifts and sleep deprivation. One really amazing thing about sleep is the way you want to think about it is we are going through a replenishment and repair process when we close our eyes and go to sleep if we're doing it well. Unfortunately, around 70% to 80% of the US population isn't doing it too well. Some of us that 70% to 80% is sedating themselves through THC or through alcohol, which they think they're sleeping through, but they're not, it's just sedation, and they're not getting sleep.
The reason why sleep is so important, and I'll try and break this down really easily, is for these two reasons, we go through different cycles as we sleep. We have four cycles or four stages. When we're falling asleep is stage one, stage two is when we're in light sleep, then stage three and four are the most important. We cycle through these four literally all throughout the night. We really want to focus on stage three and four. So, stage three is our slow wave sleep or deep sleep. It's called slow wave because on an EEG, and this is out my primary tool of use as a neurophysiologist, an EEG, which is that cap that you put on your head, there's all these leads coming out of it, but assesses the brain wave activity. When you're in deep sleep, the waves on the EEG are really big and long, and we call them slow wave sleep.
When you're in this stage of sleep, two particular things happen. One, we have the release of all of our hormones. I'm a female and so are you and so most of our hormones during this stage is estrogen, which we need, it's evidently linked to the menstrual cycle, which is why mine may not have come on time because I was sleep deprived. Now, for men, a lot of the hormones that are released is testosterone. So, it's an important stage of sleep. We need it for survival. We also get the release of growth hormone. Growth hormone is a hormone responsible for the growth and repair of muscle tissue and brain tissue, by the way. So, we need these two things.
Cynthia Thurlow: No, that's what the podcast team is for. [laughs]
Louisa Nicola: Another thing that happens during this stage is we activate the glymphatic system. This is like a sewage system in our brain. A really wonderful thing that happens is our brain cells shrink in size, the particular ones called glial cells, and they're like glue. It comes from the Greek word glue. They bind the other neurons together. They decrease in cell size and they allow for the cerebral spinal fluid to go through and wash the brain literally like a sewage system. And I'm sure you've heard of that. Yeah?
Cynthia Thurlow: Yes, oh absolutely. It's funny how I talk about how important that is. It's like the trash services in our brains that aren't activated if you're chronically dealing with sleep deprivation.
Louisa Nicola: Yeah, and one of the things that it clears out amongst many different toxins and proteins is amyloid beta. Amyloid beta is one of the hallmarks of Alzheimer's disease. You can then correlate if we aren't getting deep sleep, we're not activating this system. If we're not activating the system, we're not getting the clearing of this protein. If we didn't get the clearing of this protein, it's just going to build up. I believe in compound interest both in finances and in medicine and science. That means it's just going to keep compounding and it's going to triple and then quadruple and just keep compounding and have this plaquing effect. You don't get symptoms of it in your 30s. May not get symptoms in your 40s. Then bam as soon as you hit your 50s, you start forgetting names. You start forgetting short-term memories which is indicative of mild cognitive impairment.
And that is a pre-dementia state. So, we then think, well and then what happens if we still sleep deprive ourselves? We end up with neurodegeneration or neurodegenerative diseases such as Alzheimer's disease. That's why it's so important to sleep. Not to mention REM sleep, which is the fourth stage that I mentioned. This is characterized by rapid eye movement on an EEG. Really important because this is where our memory consolidation happens, but also our emotional first aid. I work with a lot of high-profile athletes. If they don't sleep well, and I check their sleep data every morning, I know that they're going to have a short fuse on that court. I know that they're going to break a racquet at the Australian Open. Sleep is the most underrated high-performance tool that we have.
Cynthia Thurlow: Well, it's interesting because I'm coming at things as a clinician and I always say that sleep is foundational to our health. How many people out there have had patients tell me this over the years? I'll sleep when I'm dead. Sleep is not important. I can get more work done, my kids go to bed, I just get up earlier so I can go to the gym. More often than not, I'm having to remind them that I'm coming at it from a metabolic health perspective. I remind them that if you're getting less than 6 hours a night of sleep, how that impacts blood sugar regulation, how that impacts your leptin and ghrelin signaling, how that impacts your food choices, how that impacts all these other things. I think it's so helpful to hear what's actually going on behind the scenes, if you will, in terms of sleep and brain physiology.
Now, I know that you probably work with men and women, but what is it that's unique about the perimenopause shifts that are occurring physiologically? I think a lot of women perhaps don't understand that we have hormonal signaling in the brain between progesterone and estradiol and testosterone. As women are navigating these perimenopausal, the 10 to 15 years preceding menopause, it does have a tremendous impact on sleep quality. More often than not, we kind of make excuses, "Oh, I just have more stress. Oh, it's something I ate." The things you used to lean into that helped you sleep are no longer working. What are some of the common patterns? I know there may be less athletes in their 40s and 50s, but what are some of the common things that you see in your female patients that are unique to them as opposed to men?
Louisa Nicola: I said something really controversial last week and this wasn't through my opinion. I actually read this in a neurology report. As of 2023, they want to classify perimenopause as a brain disease. Now, I want to be really careful with my wording so a lot of women don't run out there and start saying that they've got some type of brain disease. Let's look at the characteristics of perimenopause. This is what was listed in the neurology report. It was characteristic of brain fog, headaches, fluctuations in hormones, sleep I wouldn't say deprivation, but cyclic sleep, one night maybe it's bad, the other night you're up, the next night you're having a good sleep, just different types of phases of sleep and if you look at these, they are all characteristics of different forms of diseases of the brain. When we think of brain fog, it just gets thrown around. You have to think about what really is brain fog. I think that's why it's super important to understand the things that we can do for free. Sleep, nutrition, sunlight, exercise that can help aid in the penetration of naturally secreting hormones that can get infiltrated into the brain before we go through and take exogenous hormones.
Cynthia Thurlow: Yeah, it's interesting because I'm obviously of the belief system. I'm both allopathic and functionally trained, and the methodology in a more traditional mindset is if there's a one size fits all and I oftentimes will say to women there are like 10 things we need to do before we even get to supplements, before we start getting to bioidenticals, before we start getting to medication. But in many ways, allopathic medicine does things backwards. It's like, let's give you a pill to treat the sleep before we give you a pill to address the insulin resistance, before we give you a pill to address the hormonal imbalances. I think it's really interesting that that journal is effectively referring to this middle-aged transition as a disease state and that's interesting. I just had Dr. Amy Killen last month and she was calling menopause a disease state. She's like, let's call it what it is.
It is a de facto point in time when women are inflamed. There's a great deal of oxidative stress, and it doesn't have to be that way, because the net impact of that menopausal transition is changes in our rates of heart disease, bone issues, brain health issues. There are many camps if you will, and there's no judgment on my part, but there are people who feel like they have to do this ala naturel. Then there are people who are open to different types of interventions. I find the brain physiology piece, as women's brains are aging, particularly of interest, and I'm sure you're well familiar with Dr. Lisa Mosconi. I think her book scared the bejeebers out of me. If there was anything that completely allowed me to fully embrace the fact that most if not all of us really do benefit from having some degree of bioidentical hormone support. It was that book. And she's looking at women's brains. She's actually looking at both people that are still alive and then looking at post-mortem brains and looking at the changes that are going on physiologically. I think this is kind of unique obviously, your work, her work, is really important for helping people fully understand what's happening as we get older.
Louisa Nicola: Yeah. One thing to keep in mind when we're talking about the brain, it is the most vascular-rich organ in the entire body. That means that it has the most amount of vasculature. Blood vessels, capillaries, veins, all of these infiltrate the brain and they have different responsibilities. If we think about our heart, okay, our heart shoots out the blood, and obviously, the blood returns to the heart. But in terms of the brain, we have two main arteries that shoot out from the heart and go into the brain. We have the carotid arteries at the front here, then we have the vertebral arteries at the back, and they go in, and all the other little arteries branch off there. [unintelligible [00:25:58] capillaries, which, by the way, I was told on a podcast last week that in America you say capillaries. Yeah, I'm from Australia, guys. [Cynthia laughs] Capillaries are one cell thick, so they're really-- we've got to look after those because once they get damaged, which is very easy to do, once they get damaged, they die off. We can't really regenerate them. We can, it's called angiogenesis, but it's really hard to do. We're going to preserve the amount of vasculature that is in our brain. One thing that I don't think we're talking about, which starts to happen at around the perimenopause stage. If we're thinking around, we're thinking about 48.
Cynthia Thurlow: I'd say 35 to 40 is when that stage kind of starts. So 48, I would say typically latter stages of perimenopause.
Louisa Nicola: Wow, okay, So, that stage, so when we think about that, we think about blood pressure. What I think is alarming is the fact that a lot of people are only checking their blood pressure once a year when they get their yearly physical. We should be checking it each day because these fluctuations in high blood pressure cause the collapse of these tiny capillaries in the brain. So, what does that mean? That means that we're getting less oxygen and less nutrients to the brain via blood. So, that's pretty scary too.
Cynthia Thurlow: Well, and it's interesting because my whole background as an NP was in cardiology and we would do lots of carotid artery scans. We look for vertebral arteries. In cardiology, we're always looking at vessels. But what Louisa is really referring to are these tiny little tributaries that contribute to these larger vessels in the body. If they are dying off and if they're diseased, it becomes this long net word effect where we now recognize that a large contributor to high blood pressure is insulin resistance. With the bulk of the population already being insulin resistant, checking your blood pressure once a year is not enough. We should really be monitoring it in greater intervals. Now, when we're speaking about brain health, you kind of alluded to that you've had these recent issues related to jet lag. Let's talk about what jet lag is, what we can do to combat it. Because I got a lot of questions. People saying just flying out to the West Coast can be disruptive. I can't even imagine being 12 or 14 hours ahead and then coming back to the States that would be hugely impactful on how you're feeling.
Louisa Nicola: Yeah, I'm suffering. I don't think it's very good for my health. I know it's not good but jet lag is the change in our natural circadian rhythm and it can be thrown off from East Coast to West Coast in the States, but also for people who are like me, traveling 24 hours to get to another country. It's characterized by not being able to fall asleep, chronically sleep deprived, brain fog, and it's like we've got to think about ways of actually mitigating the effects of these. What's interesting is we can get jet lag and we don't even have to get on a plane. If you sleep deprive yourself for one night, you may wake up and have the exact same symptoms of a person who is jet lag. What are some of the things that we could do to help us from that? Well, other than getting on apps and setting your, which is what I do, I have an app and I put my plane times and everything like that, and it helps me throughout the day. One of the things that I find works really well on a plane if you can, is first of all hydrating. We have low pressure on this plane, and we need to be able to hydrate more than we do when we're not in a plane. That's the first thing that's going to help you with jet lag. The second thing is minimizing how much food that you're having on a plane.
One of the biggest reasons why we actually get jet lag is because of the food that we eat on a plane. Either taking your own food or not eating at all, which is really hard. I try and do it. I'm able to do it from New York to LA. And then I eat in LA. I probably just eat once on the LAX to Sydney flight home. In terms of supplementation, I have found that if you can sleep, I always say that sleep isn't like a debt that you can pay to the bank. If you can maximize on sleep before getting on a plane, it helps you out a lot because we all know that you're going to be more than likely sleep deprived no matter where you go. Even if you do, "Sleep," it's not going to be the best, most restorative sleep. You want to be able to get as much sleep before getting on that plane. But when you do, and if you do fly at night, you may want to think about supplementing and sleeping with a sleep mask, putting some earbuds in your ear, sleeping with a pillow, or whatever you can do to sleep. Some of the things that I like is phosphatidylserine and magnesium L-threonate.
I have magnesium L-threonate it works really well and I have GABA. These are just some of the things that I have in my toolkit that get me prepared to sleep. One other thing that I want to point out is, one of the biggest reasons for insomnia as we get older is stress. Our activation of the sympathetic nervous system can jolt us out of sleep and wake us up. Managing stress, especially on these long flights, is really imperative as well.
Cynthia Thurlow: I think that's really invaluable. It's interesting because I have some of those things in my toolkit. Sometimes I will fast longer. I will endeavor to eat before I go or wait until I get to my destination. Nowadays, even in most instances, you're actually not getting real food. I feel like people get handed boxes of junk, which is usually heavy on carbs, heavy on the highly processed foods which are not going to contribute to good sleep. Have you read any information on inositol or myoinositol being beneficial for jet lag?
Louisa Nicola: Inositol especially, yeah. And I would be lying if I said that I hadn't tried it before. I have. It's just not in my routine because I think if I'm already doing well on something but what I think works well is when I had the inositol, I wasn't having phosphatidylserine. Maybe having one or the other and just doing whatever you can to just stick with a plan instead of just keep adding and adding and adding. One thing you probably realize I didn't mention in there was melatonin. I actually don't have this for one, it knocks me around too much. Two, it is a hormone at the end of the day, so we need to be careful with having exogenous hormones, just like I'm not having exogenous estrogen or testosterone. We have to be careful with how much we're putting in there. Due to the fact that when we land in our destination, we want to get on time, wherever we are on that time, as soon as possible, and delaying that because of melatonin is just going to throw us off our mark.
Cynthia Thurlow: That's a great point. And it's interesting, I do take melatonin. Not when I'm traveling, however because again, to your point, you don't want to get off the plane and be trying to metabolize off melatonin and really struggling. It's interesting, I was telling someone recently that I started using a new type of melatonin and it had both a sustained and an acute onset. I was explaining that I had taken too much and the next morning what I did was I went right outside, got sunlight exposure on my retinas because I knew that would help suppress some of this exogenous melatonin, I had taken so that I could kind of start getting my cortisol back up and start getting my day started. Now, are you a fan when you get to your destination to take a nap, or do you just power through your day, which is what I typically do, and then just go to bed a little earlier? Like I will try to keep myself moving and awake as much as possible.
Louisa Nicola: Yeah. When I went to LA. I landed in LAX from Sydney, so that was a 13.5-hour flight and it was 06:30 in the morning and I didn't sleep at all on the plane. Sometimes it's a hit and miss, sometimes I sleep, sometimes I don't. But this time I didn't sleep, so I stayed up all day in LA. It was traumatizing, but I was thankful for it because if I slept then I probably wouldn't have slept at night. So, I'm a fan of doing that and when you look at the scientific literature, the best way to accustom yourself to a new time zone is by sunlight, obviously number one, but also exercising. It signals different things to your brain that says, I'm awake, release the cortisol, keep me up. This is a time of day that we work out, so, yeah, I try and stay up the entire day.
Cynthia Thurlow: That's impressive, especially if you weren't able to sleep properly on the plane and I know that's not any fun. Now, one of the more common things that I start seeing in terms of lifestyle that women will do as they're navigating perimenopause and menopause, is that they start having trouble sleeping and they start using alcohol as a means of falling asleep. Let's talk about the science, about not only what alcohol does to the brain, but the net impact it provides to sleep, which everything that I've read for this interview is not a positive thing.
Louisa Nicola: Yeah, alcohol. He put up this post yesterday on Instagram and it just went viral and I think it hit a nerve with some people and it said, I know this is going to be a hard pill to swallow, but no amount of alcohol is good for the brain. I don't know where we started to think that it was. Let's talk about in the awake state and what we're doing is you're actually killing off these wonderful things that make up our brain. We've got 87 billion neurons in the brain and with these 87 billion neurons, we've got around 15,000 to 30,000 connections per neuron. You have to think the amount of activity that is happening in the brain just to keep us up and awake and active. When we drink, we're killing off these neurons. It doesn't matter if it's one drink or ten drinks, obviously, if it's ten drinks, it's a lot more.
You are killing your brain cells when you drink, so there is no benefit to it. The active ingredient in alcohol is ethanol. This is like a sedative. We have sedatives such as propofol when we're going to surgery and it sedates you. Instead of thinking that it's putting you to sleep, it's sedating you. So, it's knocking you out. It's kicking you out of REM sleep and kicking you out of deep sleep. You're sedated, your low-level asleep, if you will, at night, but you're not asleep. You don't get into these stages, so you don't get the replenishment that we need that we're speaking about earlier.
Cynthia Thurlow: It's interesting, I've spoken very openly that I've never been a big drinker. I was never very interested in drinking alcohol. Got made fun of it in my teens and 20s, and during the pandemic, I said to my husband, I was only a social drinker. With having no social life during the pandemic, it made me realize I was like, why am I drinking? It's the only thing that gives me hot flashes. It's clearly not working for me. It's amazing to me, the more I start talking about the fact that I don't drink alcohol, the more I realize there are a lot of people in the health and wellness space that don't drink alcohol for a variety of reasons. Yet to me, this kind of information just reaffirms why we have to be careful about our choices. To your point, I think I had a reel probably a couple of months ago, and it was amazing to see the visceral reactions that people were leaning into this reel, talking about what it was doing physiologically and how many people were like, "Oh, yeah, I stopped drinking alcohol because of this, this, and this," and "Oh, this person stopped drinking alcohol."
You get a few people that get triggered by posts like that, and you just say, I'm just trying to provide good information. Much to your point as well. I think Huberman did a podcast, maybe it was in September or October, and I was sharing it with a colleague. My colleague said, my spouse is such an avid wine drinker, I'm not sure I can even get them interested in listening to this. I said all you can do is just provide information. We're here to educate and inspire people and help them understand what's going on physiologically with the brain. It was interesting when I was kind of looking at the research in preparation for today, you had said the damaging effects to the prefrontal cortex, which is our executive function part of the brain and rewiring of neural circuitry are reversible with two to six months of abstinence for most social and casual drinkers, chronic users will partially recover, but likely will feel long-lasting effects. Can you explain why that actually happens, why the longtime users are going to have a permanent impact on brain health and physiology?
Louisa Nicola: It's interesting because when you look at the studies on chronic smokers, right, we know how detrimental smoking is for health. But did you know that abstinence from smoking or cessation of smoking over a five-year period can reverse and you can go back to zero just with that one cessation? So, that's amazing. First of all, when we talk about the killing off the neurons in the prefrontal cortex, a prefrontal cortex sits just here. It's part of the frontal lobe. That's the newest member of the family, the newest member of the brain family and the biggest. When I say biggest, I don't just mean in volume, I mean in neural circuitry. It houses the most amount of neurons, which is why when we drink we get lowered cognitive functions. Our cognitive functions are reaction time, thinking, focus, attention, memory, these things, they live just here in the prefrontal cortex.
If we're killing off the neurons and killing off the connections, evidently, we're going to have a lower cognitive status or cognitive ability. That's the first part of what we just said, and they can recuperate. Okay? If we have just a casual drink the next day, if we sleep and exercise, and hydrate, we can get back on the bandwagon because let me just say, I'm not a complete party pooper, complete downer, one drink probably won't have an effect. Let's just call it what it is. The studies that I mentioned speak about the effects coming from seven drinks a week. Seven drinks could be one a day. It could be seven all in one day. Whatever it is, it's just seven drinks. That's where we're talking okay, that's when these processes start to happen. Let's double that and let's talk about eight drinks a week that then becomes-- and this is for a female. So, seven drinks for a female, eight drinks for a male, and then chronic then becomes 16 drinks for a male and eight drinks. Sorry, I'm doing the math wrong. 14 drinks for a female and 14 drinks a week for a male. Sorry, guys. That's when it starts to become more than moderate. We move out of the moderate stage, and we move into the chronic stage.
That's when we start to see irreversible damage. Because when we kill off areas of the brain, this happens in a stroke, okay? If we have a stroke, a stroke is literally a cerebral infarction which is an occlusion of a blood vessel. Occlusion or blocking of that blood vessel. If we block it, therefore the blood cannot be delivered to that area of the brain. Therefore, the cells in that area die and we do not regenerate. We don't have neurogenesis. The only part neurogenesis has a place is in the hippocampus. So, when we kill off that area of the brain during a stroke or during heavy drinking, the brain tissue does not grow back. What happens is the areas around it and they're called the subregions of which area has been killed off that grow back stronger to try and compensate, but you don't fully get back that part that you've killed off in the first place.
Cynthia Thurlow: It's really interesting because sometimes in the heart, you'll get collateralization. If there's been an infarct or a death in a myocyte, sometimes you'll get collateralization of blood vessels. It sounds like there's this compensatory mechanism in response to a CVA or cerebrovascular accident.
Louisa Nicola: Yeah, cardiologists hate when I say this, but I always say that the brain is more important than the heart.
Cynthia Thurlow: [laughter] I can imagine. Yes, cardiologists tend to be very myopic. The heart is the most important organ in the body.
Louisa Nicola: I just want to point out that there is something beautiful when it comes to the heart. We have something called cardiac remodeling, where when we exercise and we generate more blood flow and we exercise the muscles of our heart, they get stronger, they get thicker, and that is called cardiac remodeling. I love that because what happens is when our heart beats, it pumps blood with every beat. If our ventricles are stronger, because remember, our blood vessels have muscles. If they get stronger, therefore, for every heartbeat, we can pump out more blood with more blood that goes to the tissues, to the lungs, to the brain, to every organ in our body, it delivers more oxygen per beat. If we can get a stronger heart, then we can get stronger blood flow with every beat. I love that when it comes to heart health.
Cynthia Thurlow: Absolutely. This is probably a great time to kind of shift the conversation and talk about the value of exercise as it pertains to brain health. It's interesting, to me I always learn so much. I was telling Louisa before we started having a conversation that I don't subscribe to a lot of newsletters, but I do subscribe to yours because there's some nugget every single time I receive the newsletter, which is a few times a week that I takeaway and I'm able to actually utilize effectively in my practice and in my business. Let's talk about what types of exercise impact brain health and why a variety of different types of exercise are so important.
Louisa Nicola: Exercise is fundamentally out of the three pillars; I think the most important for a number of reasons. When we talk about exercise, we're talking about aerobic activity, which is like your long-distance running, your power walking, you're cycling. We've got resistance training, which is your weights, any form of resistance against the muscles. We've also got Neuro Athletics training, which is the cognitive training, reaction time, processing speed, memory drills. So, let's first look at aerobic training, what does it do? Well, over an extended time, let's say 45 minutes of aerobic physical activity, you're exercising the muscles of the heart, that's one. What you're also doing is you're getting an infiltration of a hormone that this hormone gets secreted and it goes into your bloodstream and then up into your brain. And that is called BDNF. It's a hormone, but it's also a myokine, and it stands for brain-derived neurotrophic factor.
When you exercise, when you get the release of that, which is you get a massive robust release of BDNF. BDNF signals to different areas in the brain and it tells it to grow new neurons in the hippocampus. There was a study that was done, one of the first studies on rodents, that showed that six months of wheel running or aerobic physical activity grows new neurons in the hippocampus. More studies on the exact same type of models showed that you can stave off Alzheimer's disease by 20 years from doing physical activity a minimum of 20 minutes a day, which is amazing. Not to mention that if you're doing aerobics physical activity in zone two, which is around 65% of your maximum heart rate, you're training the mitochondria of the cells, more mitochondria, which is mitochondrial biogenesis can help in the longevity process, it can actually help out.
One thing that I'm starting to discover now is the relationship of exercise and fertility. This is because I've been reading a lot now about athletes who went through-- and this is probably more your area. It's not my area. I'm learning about it, though. Athletes who had amenorrhea, is that how we call it? They didn't have their period during their Olympic stages, and then they're having births or they're falling pregnant at around 39, 40. And I was really interested in that. It got me down the rabbit hole of exercise and then mitochondrial health and how mitochondria is linked to fertility, and that we have mitochondria in the ovum. So, I went down this rabbit hole. This is literally a week ago. So, that's another area to love. But let's stick to the brain. So, that's aerobic activity.
Then. Let's move on to resistance training, which is my niche and resistance training offers an abundance if not more beneficial effects than aerobic training. When we're doing forms of resistance against the muscle, and I'm talking, you've got to have a heavy load. Let's just take bench press or a squat, for example. We're doing a number of things. First of all, let's focus on the legs because they're the biggest in terms of vector size, the biggest muscle groups in the body. When we're exercising the muscles, they're pushing against our veins. Now, our veins are not like our arteries. They don't have muscles. What they are is they are a one-directional pump. We have to squeeze them in order to get the muscle in order to get the blood pushing through the vein, which then goes up into the vena cava, which then goes into the lungs. We need to be pushing that. When we do resistance training, our muscles are squeezing together and pushing up the blood through our veins, so that's one thing. We're getting adequate blood flow.
The next thing we're getting is we're getting a release of myokines. I mentioned it earlier, we have BDNF during aerobic training, but my God, we have a million times more. The newsletter that went out last night focused on two myokines, interleukin‐6 and irisin. Just to mention, we've got 611 discovered myokines over the next two years.
Cynthia Thurlow: That's okay.
Louisa Nicola: [Cynthia laughs] We have the release of these myokines. When myokines are released from skeletal muscle, they go into the bloodstream. When they go into the bloodstream, they travel up. They cross our blood-brain barrier, which is a unique structure in and of itself. It crosses the blood-brain barrier. Depending on which type of myokine it is, let's take irisin for example. Irisin is a messenger molecule. It was actually named after the Greek god of Iris, who was a messenger to the god and irisin does the same thing. It's my favorite and it's the sexiest hormone on the market right now. When it comes to myokines, it goes in and as a messenger it will tap on the walls, if you will, and it will say, "Hey, BDNF, I need you to work a bit harder, BDNF." So BDNF then gets expressed even more.
And then BDNF is like, "Okay, guys, irisin's here, let's go into the hippocampus and let's grow new neurons, let's get to work." So, that's how irisin works. Irisin also binds to receptors in the frontal lobe. When it does that it knocks on those little areas and says, "Hey, executive functions, I'm here. I'm the Greek God. I need you guys to work on reaction time. I need you there. I need you guys to be picking up attention. Hey focus, I need you to be picking up your game." It has so many effects. It's a wonderful hormone. But here's the caveat. You have to be lifting hard. You can't just go into the gym, lift a tiny little weight, which I see women doing all the time, sorry, I don't know why. You have to be lifting at 75% of your maximum, one repetition max. If you're able to squat 100 kilos for argument's sake, that means you should be working at you should be having 70 kilos, okay or 75 kilos, which is 75% of 100 kilos on that weight. You should be doing around six reps, six to eight reps if you can. That's a heavy load. The heavier, the more robust the release of myokines. Does that make sense?
Cynthia Thurlow: It does. I think it's really interesting and for listeners to know that I had written about the role of irisin, one of the things it does it increases the uptake of glucose and skeletal muscle. For me, I was thinking about the fact as I was lifting heavy legs, I do two