Transcription
What are the five most important things—let's say five things—I think you've mentioned five already.
Five most important things we can do to help our brain health and maybe in order of importance if you had to pick.
Oh, okay! Well, I'm biased because I'm currently—I mentioned to you that I'm currently doing my doctorate. It's literally in exercise and mild cognitive impairment, so I'm looking at many different studies, interventions such as resistance training, aerobic training, and what these have on global cognition and on the structural components of the brain.
So I think at the bottom of the pyramid, the best thing that you can be doing is exercising. I know that the sleep people and the nutrition people probably have something else to say, but let's talk about exercise and what that's doing.
Yeah, so we've got aerobic training, and that's generally your long-distance running. It's generally when you're getting a lot of blood flow through the brain. Remember you mentioned earlier heart health, and it's the same thing with the brain. What's good for the heart is good for the brain and good for your genitals, as you mentioned. Yes, and good for your genitals! Why? Because there's blood; there are blood vessels to the genitals, and they're usually smaller than those to the heart or the brain. So you’re going to see problems in your genitals long before you see them elsewhere.
Correct, and your brain is the most vascular-rich organ in the entire body, meaning it is infiltrated with blood vessels, capillaries, veins—like these are important structural components of the brain.
So let’s just actually think about the heart for a moment. Okay, you've got the aorta, and branching off the aorta, you've got the carotid arteries, and then you've got the vertebral arteries, which is the posterior blood supply to the brain, and everything else is just branching off of these two arteries.
So every time your heart pumps, you get a massive profusion—big or small—of blood to the brain. The brain loves that because you’re getting an influx of nutrients and oxygen, and we need that. It turns out that even the smallest one-cell-thick capillaries in your brain need to be utilized because they are essentially providing your brain with blood. Oftentimes during cognitive decline, they are the first things to go; they go under stress.
So the first things to go during hypertension and elevated blood pressure are your capillaries. So every time you kill off a tiny little supply of blood to the brain, what happens? That means the neuron is not getting fed, so it dies. So we need to maintain our vasculature. And how do we do that? Through adequate blood flow. How do we do that? Through exercise.
So there’s—uh, you know, aerobic exercise is the most widely studied when it comes to cognitive impairment and dementia because we started off with obviously mice studies. You can just get a mouse to run on a wheel. The best thing that it does is when you are exercising, you get a rapid release of a neurotrophic factor, or brain-derived neurotrophic factor (BDNF), and this is a growth factor for the brain.
So what scientists realized early on was that when you do as little as 20 minutes of exercise, you release BDNF. And BDNF, when it acts as a growth factor in the brain, goes into the hippocampus and is responsible for the growth and proliferation of new neurons.
So it can grow new neurons in the hippocampus. There's also been two-year follow-up studies that have shown an increase in hippocampal volume—so growing the hippocampus. Now, whether that—and the hippocampal subregions as well—whether that directly relates to improvements in cognition is dependent on the person, but we know that exercise is great for that.
What else is aerobic activity doing? Actually, a really wonderful study was done out of Ben Levine’s group. He’s a cardiologist by training. What he did, Reena, was he took 53 50-year-olds—sedentary, otherwise healthy 50-year-olds. He subjected them to 4 hours of maximal exercise per week—and when I say maximal, I'm talking it was around 75% of their maximum heart rate—four hours a week, so it was pretty a lot.
He did this as an intervention for 2 years. Guess what he found? He reversed the age-related decline of your heart by 20 years. So he was looking at the hearts of these 50-year-olds, and they were presenting with the hearts of 30-year-olds.
He saw this through something called cardiac remodeling. As we age, we get stiffening of the ventricles—specifically, we get left ventricular stiffness—so that it hypertrophies, so it gets bigger, and it constricts our blood, so therefore we can't get a lot of blood through stroke volume per pump.
Okay, so that's scary because that means with every heartbeat, we have less blood flow going to the brain. He improved that over time, and I think that that is absolutely incredible.
We call that cardiac remodeling, so you can literally remodel your cardiac system; your cardiac system is just like your muscular system. Through cardiac remodeling, through putting your body under these stressful situations, you can rewire your actual heart so it can be pumping better.
And remember, your arteries—these big blood vessels—are actually made of muscle, so the stronger they are, the better equipped they are delivering blood to the brain. So remember blood flow. Then we'll move on and we can talk about, you know—and we know this; I know you've done—you’ve had Dr. Andy Galpin on the podcast, and he spoke tremendously about VO2 Max, which is a measure of your cardiorespiratory fitness.
We know that even just an increase in your VO2 Max can give you a life. If you go from below average to above average, it can give you an increased life expectancy of 5 years. So I think everyone—in terms of protocols—I think everyone should understand their baseline, where they sit for their fitness.
I think everyone should get a VO2 Max test, because it is in the pursuit of a higher VO2 Max that you get the real benefits. It's not about the number; it is about "What do I have to do to increase my VO2 Max?" This doesn't happen—you know, you can't just—you can go and get blood work done. Let’s just say you’ve got low vitamin D; you can go and just take maybe 10,000 IU of vitamin D per day for two, three months and you go back and get a blood test. You’ll see a dramatic increase.
It's not the same for VO2 Max; to increase your VO2 Max, you really need to be stressing your system on a daily basis. So in the pursuit of that is where you’ll get the benefits.
Yeah, and you posted something very recently—I think it was on your stories—maybe about one point of VO2 Max increase led to some really dramatic change. What was that?
A 45-day increase in life expectancy.
So improving your VO2 Max by one point improves your lifespan by 45 days. That is correct!
Yeah, that's really impressive. It is, and it is because of the changes in the heart.
Yeah, so we know now, based on what you've told me, that improving your aerobic exercise daily at a reasonable VO2 Max—around 75%—it seems like you'll see improvements in cardiac remodeling.
You'll see improvement in hippocampal volume, and in terms of sexual function, you'll see improvement in erections for men and probably similar improvements in arousal for women in terms of clitoral turgor.
Really great reasons to incorporate aerobic exercise: improvements in global cognition as well. And globally, I would assume that that would be related to your hippocampal volume, but yes, absolutely.
Yeah, and then we move on to resistance training, which—again, biased to it—but I think that it offers a tremendous amount of positivity to the brain from a structural perspective, right?
And my area of expertise is in EEG (electroencephalography), where you actually measure the connectivity of the brain, the functionality of the brain. But then when we look at the structural components of the brain—which, you know, you can see through an MRI, for example—we can see changes in the gray matter cortex.
There was one study that I came across, and this was back in, I think, 2016, which showed that 80% of brain gray matter is modifiable by exercise. And for the audience, what is gray matter?
So we've got both gray matter and white matter. The gray matter sits on the outer cortex of the brain; it's generally made up of the neuron cell bodies. That's why, if you see it on appearance, it can come darker.
Then the white matter is our axons; it's the myelinated neurons. These are the things that you know are responsible for conduction and conduction speed and velocity. This is what you'll test if you go and get a nerve conduction study or an EMG, and someone is, you know, being picked up on—for example, multiple sclerosis. You’ll see complete conduction block or slowing of conduction speed.
So, that's the white matter of the brain, and that's deep within the brain. The outside is your gray matter, and that thins over time. We get thinning of the gray matter cortex due to age as well; however, it doesn't have to be this way.
We do get the loss of neurons as we get older. Arguably, over the age of around 25 to 30, we start to see an atrophy in our brain.
And are those neurons—like is that reversible?
It's preventable, but it’s not—adult neurogenesis, unfortunately—very controversial as well—doesn't exist, from what I've seen in the literature, outside of the hippocampus.
So, I mean, look, if that was true, we’d all be running around growing new brain cells. It'd be amazing! Yes, angiogenesis and synaptogenesis exist. So, genesis—creation—you can create new synapses and new connections. We know that to be true through neuroplasticity, and there's great research coming out now on Lion’s mane and other adaptogens that can really help with that process.
But back to resistance training, there was a wonderful study that really signified my understanding and love for this field, and that was by Harold Attal, who basically did a systematic review of all of the literature on resistance training and mild cognitive impairment.
He found many things. One thing was Benedi, she’s a wonderful researcher; she coined this term called “myokine.” A myokine is a muscle-based protein coming from the cytokine family. What she found was that under the contraction of a muscle fiber—when you contract it and you squeeze it together—you have the release of these proteins that are only released from the muscle fiber when they’re released.
They go into the bloodstream, and they can cross the blood-brain barrier and can go through and connect on different receptors in the brain and have positive effects on the brain.
So, for example, there is one called irisin. Irisin is a myokine named after the Greek god of Iris, because it acts as a messenger molecule. So when it’s released from the muscle belly, it goes up, crosses the blood-brain barrier, and improves the proliferation of BDNF. So it actually helps BDNF express itself more.
We've got cathepsin B—so all of these wonderful myokines that are literally like fertilizer for the brain. But not just that; we know that these can go into other organs such as the prostate. We've got receptors on the prostate, on the ovaries, we’ve got receptors on our liver.
And there's a really great study now in Cell Press that showed that exercise via lactate—which lactate is another byproduct of exercise, but it’s also another myokine—can actually inhibit tumor cell growth.
Really?
Yeah! Doing resistance training is improving this myokine release, which is then going to our brains and having improvements in, basically, a multitude of ways.
Multitude, yeah. Which can be, you know, these wonderful growth factors that help our brains function better and potentially have—uh, prol?
Yes, absolutely! That's a really good sum.
Yeah, and just to—just these myokines are not anywhere else. They are literally released under tension. You have to really be lifting high. This is why, when you're going to the gym, you should be lifting—you know, you have to be lifting hard, not these tiny little weights because you want to put your muscles under tension for them to release these growth factors.
But we’ve got circulating tumor cells that can actually be downregulated through aerobic physical activity and also through the myokine release.
Yeah, that’s—that's—I mean, I love lifting, and I think it's like addictive. Like once you—like, "Oh, I can lift more!" Like, it's actually really fun.
Yeah, and you’ve also seen the studies of the age-related loss in our strength and muscle. So even just for the creation of, like, stronger muscles, stronger, you know, more strength as we age, because one of the number one causes of death—the CDC actually released this—over the age of 80 is falls.
Mhm, and that's really scary. And then you think, if you reverse engineer everything, right? Well, why do we fall? Okay, sometimes cognition, you know, lack of cognition of where to actually know where you are in space and time can cause that.
We see balance. You know, you can get atrophy in the cerebellum, which is the mini brain, if you will, and that is responsible for our balance and coordination. So that can also result in it, but then we also know that strength, obviously—and muscle loss—psychop, can result in that.
Yeah, absolutely. I mean, falls are some of the things I worry about very much so in my patients because a lot of them wake up at night to urinate, and then that leads to falls because they're getting up—they're, you know, in the middle of the night where they're not fully alert yet; it's dark.
There's so many things that we talk about with our patients, but ultimately, you know, I don't think people realize how bad a fall is when you're in your 70s and 80s and how that can literally increase your mortality risk by 20%, you know, just from having a fall within that first year.
So it is really important—so strength is going to help with that as well.
So, okay, we talked about aerobic exercise, resistance exercise. What's next?
The other one is a subspecialty. So my company is actually called Neuro Athletics, and I founded this in 2014, and that was because there is a third part of exercise that we all neglect, and that's neurocognitive training.
It is things using things such as your reaction training, which is actually so beneficial for the brain. Many people say to me, "Louisa, can I just do a puzzle or Sudoku?" If it places your brain under pressure, then yes, because your brain will adapt to it.
But a really great thing that you can do is just get two handballs and throw them to the wall, and that's part of this neurocognitive training: reaction training, hand-eye coordination, balance—these things are actually worthwhile to do as you age.
Yeah, so let’s break that down. How often should you do this, and how—with what regularity? In terms of like, how long should you be spending?
Something you only really need to do around 7 to 10 minutes a day. There’s been great studies that have shown that juggling can actually improve the gray matter cortex.
So Sudoku is not enough?
Sudoku is not enough!
Okay, good, ‘cause my mom's obsessed.
But do you know what's actually good? Yeah! Like anything where you’re learning—a new language.
One thing that we do with some of our clients too is we take into consideration the auditory cortex. We know that hearing loss is another risk factor for dementia.
But, you know, doing like hearing tests—like maybe react to a sound that you can hear. Or we do eye patches at Neuro Athletics. We get some people to wear an eye patch, which literally closes off half of your brain; it closes off half of your visual cortex.
So it makes your brain work harder because it thinks, "Oh my gosh, I've only got 50% of my vision; I have to work harder," and it places your brain under stress.
Yeah, that’s a— or complete blindfold?
Yeah!
Yeah, but I guess you can be progressive about it, right? Like you can do it with both eyes open, you can do it with one eye patch on, with a blindfold, work your way through.
Yeah, exactly, and it's fun! Anyone can do it; it’s cheap—7 minutes a day. Just get a handball and throw it to the wall and just try and not drop it for a minute. If you don't do that, then go to 2 minutes and then 3 minutes.
It seems like it's something you could do with your kids. Like for me, my boys would love that.
Yeah, yeah, absolutely!
Okay, so we've got aerobic exercise, resistance exercise, neurocognitive training. What else?
And then one really great study—which I’d be remiss if I didn't speak about this—has nothing to do with exercise per se, but it’s got to do with the quality of the connections that you have.
So there was an 80-year study that was done out of Harvard, which showed that the number one thing for a healthy, performing brain in your 80s, 90s, and beyond is the quality of your relationships.
It doesn't just mean the quality of your romantic relationships; it is: do you have supportive people around you? Creating a really great social network is going to be key to a healthy brain as well.
That is so important! And I, you know, I see a lot of older patients, and I often ask them, like, "What are you doing?" Because sometimes their partners have passed away, or, you know, the closest people to them are getting older.
And the ones that thrive are the ones who get involved in their community in some way. They may go to bridge games; they may go golfing with their buddies that they still have or make new friends, and that is really—or they’ll volunteer. Even going to the library and volunteering or something—and that's sort of how they maintain those social connections.
Because I think even there’s some data that even the small connections, like the connections you have with people in passing, are also very important to foster because they help us connect with people in a different way.
Yeah, and then you think about, well, why is that? It could be the release of different neurochemicals when you’re with somebody else and you’re bonding, and that could be really great.
It could be the fact that you could be learning from somebody else because your brain is like, "Oh, I’m learning from somebody else; I'm learning new things." More connections, more growth.
But if you understand the structural components, which I mentioned, we need adequate blood flow to feed the neurons. What we don’t want is neuron loss!
So how do we keep getting blood flow to the brain? How do we keep strengthening the connections between the brain?
And then we’ll talk—now we can shift gears and talk about sleep because then that's also probably the next pillar of what you can be doing to help a healthy, performing brain as well.
So we’ve done exercise, we've done stress—lower stress—we’ve done positive social connections, and now we’ll do the fourth one, which is sleep.
Sleep is not just this nocturnal thing that we go through; it is a repair process that is absolutely imperative for your brain.
We can just categorize it as we've got REM sleep and we've got deep sleep, and your brain needs both of them. There’s now—the latest research is actually showing that regularity is more important than quantity and quality.
Really?
I would argue it is all important, but regularity—the time that you go to sleep. Remember, Reena, what did I say to you at the start? Your brain loves regularity. It loves familiarity. It just wants to do the same thing every day; don’t shock it; don’t scare it, right?
And so we’ve got a really wonderful process, and this is stage three sleep. So we’ve got stage one when we’re falling asleep; stage two we’re in light sleep—these are non-rapid eye movement.
Then we’re going to non-REM stage three sleep, and on an EEG—did you ever go into a PSG?
I’ve actually—my son had one.
Oh, nice! Okay!
Well, what you’d see is you’d see these big long waves, and they called them slow delta waves. But slow wave sleep—which is also—sorry, PSG is a polysomnograph or a sleep study for those of you listening or watching—and you know, when you go in there, you’ve got a lot.
I want everyone to know, like—’cause everyone’s like, “What’s the difference between that and maybe a wearable?” There’s a lot; you know, we're monitoring a lot of activity during that.
But you see what happens during this stage—this delta wave pattern is we know that your brain does many things. One thing is this is where we get the release of testosterone.
Mhm! It was—95% of male testosterone is released during deep sleep.
Not 95, but a lot! What happens in testosterone is you release the highest amount between 7:00 and 10:00 AM, and then it sort of goes through a pulsatile, but slowly weaning throughout the day, and then it starts releasing again around 2:00 to 4:00 AM and goes back upwards, but it starts in sleep.
And that would be in deep sleep. It's probably most important for that first four hours of sleep.
So, like going to sleep from 10:00 to 2:00 rather than, like, the 2:00 to 6:00 or, you know, that sort of time frame is more important.
And that's why timing matters, right? We also get the release of growth hormone during that stage, which is responsible for the growth and repair of our muscles.
So this is why when we’re in deep sleep, it is a repair process for our brain. But we also know that we activate a system which is similar to a washing machine, if you will; it’s called the glymphatic system.
Now, I mentioned neurons. What sticks between the neurons are these other types of cells—it’s our chief immunity cell in the brain, and they’re called glial cells.
Comes from the Greek word for glue. Can you tell I’m Greek?
And they bind together between the two neurons, and they shrink in size during deep sleep. And when they shrink, it means that we can have our cerebral spinal fluid wash away in this beautiful synchronous way, and it gets excreted, taking with it toxins, taking with it the hallmarks of Alzheimer’s disease, which is amyloid beta, and it washes it through the brain, washes it out through the system.
So you wake up, you feel good! Normally, if you wake up and you've got brain fog—which is probably quite a big symptom of, you know, maybe you just didn't get enough deep sleep—and you activate this system.
This system is blocked if you’re having marijuana or alcohol.
Mhm! I just want everyone to know that it can also be blocked under certain medications as well.
Yeah, so that's—you know, the deep sleep thing. I think people don’t realize, like, what makes good quality sleep.
Oh yeah, I think really—people like, “Well, yeah, I’m sleeping 7-8 hours; you know, I’m getting the right amount of sleep.”
And I always, you know, for me, I didn't even realize it either—I am used to drink—I mean, I’m a physician, so we drink coffee all the time, so I used to drink coffee late in the day.
And I realized when I stopped that—and I started—I could fall asleep fine; I mean, I was chronically sleep deprived as a resident; I could fall asleep anywhere! But I would fall asleep fine, but I’d still feel tired.
And I realized once I limited my caffeine intake to prior to noon, I actually—and now I drink…definitely a lot of the times—my sleep is way better.
Well, that’s because caffeine, obviously, there's a half-life to it, so it interrupts sleep.
And caffeine is an adenosine blocker, which we know adenosine builds up during the day, which makes us tired.
Yeah, and so we want to try and do everything we can. You know, I always say you’re preparing for sleep the day before or the morning that you wake up—you are setting your circadian rhythm from the first time you see sunlight.
Around, you know, 12 hours after that is when we’re going to get tired. We really want to be in deep sleep.
And then another thing that will kick you out of that stage as well is light. And you think, “Well, I’ve got a dark room,” but even the smallest amount—maybe a street light.
For my parents, you know, street lights—I live in New York City; I mean, there’s light everywhere, but I wear a mask every night!
So there’s one more thing, and this is new research in the last, I would say, six years. We know that in order to fall asleep and stay asleep, our core body temperature needs to drop 2°.
So keeping a cool environment can help you. There’s a difference between ambient temperature—the temperature of the room—and your actual thermal temperature.
Some people like to sleep on a thermal mattress, and then—but if you don’t have that, you don’t need it; you can obviously tamper with the temperature in your room or even sleep with your feet outside of the sheets because that's where we, you know, get rid of our—
Is wearing socks actually reducing your core body temperature?
Yeah, it does!
So doing all these tiny little—oh, I hate the word “hacks”—but these tiny little things can really make an improvement at lowering your core body temperature throughout the night and enabling you to have a deep sleep.
So sleep regularity, though, is number one. So even on the weekends, sleeping in on the weekends, probably not a deal.
No! And remember, your sleep isn't like—it’s not like debt that you repay to the bank.
So it’s not like, “I’ll sleep 12 hours on the weekend.”
I know, right?
And one thing I want everyone to know is the study that changed my life. There’s, you know, there’s always—there’s either always a patient, a client, or a study that changes you, and the one that changed me for the game was a study done on healthy adult men.
And it was published in PNAS where they subjected them to sleep deprivation of just one week.
Sleep deprivation, by the way—guess what? How many hours?
6 hours?
Yeah, you know which one I’m talking about! It’s the epigenetic change. You’ve probably mentioned it, but that changed the game for me where they found a change in 71 genes.
The ones that were upregulated were the ones responsible for tumor growth; the ones that were downregulated were the ones responsible for immunity.
Yeah, it’s so interesting!
I mean, I think sleep—I love talking about sleep, and I think that the one—we’re the only species—and Matt Walker says this—we’re the only species who intentionally sleep deprive ourselves.
Our brains hurt us sometimes too, right? Because we let ourselves think, “Oh, I just want to do this one more thing before bed,” or “I just want to—like, I want to doom scroll or watch another episode of TV,” or whatever it is that we feel we need.
When actually the most restorative thing would be to go to sleep.
Absolutely! Absolutely, and unfortunately, what happens even when you get the, you know, the buildup of these amyloid plaques, it has this cycle where if you don’t sleep, you know, you raise your risk of developing these disorders, but then when you have it, it also prevents you from sleeping.
Yeah, it’s really, really tough.