Surprising Health Benefits of Sauna and Cold Exposure with Dr. Rhonda Patrick

Music.

Hello my friends and welcome to Biohacker's podcast. I'm your host Teemu Arina from

Biohacker Center and in today's episode we are going to talk about the health

benefits of sauna and cold exposure. Our guest today is Dr. Rhonda Patrick who

Finland. It is still relevant so I decided to share that amazing recording with you. Dr. Rhonda Patrick is a renowned biochemist and expert in the field of

nutrigenomics. Her research has been published in several prestigious scientific journals and she has worked at renowned institutions like the Salt

Lake Institute for Biological Sciences. Dr. Rhonda Patrick has focused her research on topics such as mitochondrial metabolism, aging and the effect of

micronutrient deficiencies on our health. She's also passionate about promoting a.

Preventive approach to health and longevity by advocating for practices like exercise, sauna use and cold exposure. Today we will be listening Dr. Rhonda Patrick talking

about hormetic stressors and how practices like sauna use and cold exposure can have health

benefits. In this talk she dives into the science behind these practices and shares her insights

on how they can improve our overall health and well-being. So without further ado let's listen

to what Dr. Rhonda Patrick has to say.

I'm very excited to be here in a country that has more saunas than people because I love saunas.

And apparently you guys must also like saunas. Today my talk is going to focus much on some of the health benefits

that saunas have on the brain and also on overall longevity.

I'm also going to dive a little bit into cold water and how cold water can also affect the brain as well as metabolism and other health benefits as well.

But today my talk is going to begin with a personal story about stress.

Stress. So there's good stress and there's bad stress. For me, when I was a graduate

student getting my PhD, I was experiencing a combination of both good and bad stress.

The good stress was I was learning how to be a scientist. I was learning tools and techniques

to answer interesting scientific questions that I had. And that was good. I was adapting

to that stress. But there's also bad stress that I experienced in graduate school, and

came along with many different exams, multiple exams, failed experiments, experiments that would

take me three months to set up and would fail, and 16-hour experiments I had to perform again

and again. I was not adapting to that stress. I was experiencing a sense of, at times, crippling

anxiety, which I think everyone in this room has probably experienced some form of anxiety in their

their lives before so we can all relate to that. So I was not adapting to that

stress and it was having negative effects on my health. I was getting poor sleep. So I decided to try to counter that stress, bad stress, with good stress.

And good stress is a type of stress that is a short-term stressor on the body,

something that is slightly stressful, that activates all these genetic pathways that are hard encoded in our genes that are able to deal with stress.

And so what ends up happening is that tiny bit of short-term stressor ends up not only

compensating for that stress, but you end up having a net resilience effect.

And this is often referred to as hormesis. So you have a little tiny bit of stress and it activates all these stress response pathways.

The reason we have these stress response genetic pathways is because life itself is stressful,

normal living, normal breathing and oxygen and eating food causes stress on our body.

We are making metabolic byproducts, reactive oxygen species, like every second it's happening

right now as I talk. So we're able to handle this, these types of stresses with various genetic

pathways. But when you can flip that switch on to those genetic pathways with something that's just

slightly stressful in the body, something like exercise, then you have this net resilience

effect and you adapt to that stress and you're able to handle it better and not

only are you able to handle that stress better but you become better.

Additionally, another type of hormetic stressor is actually heat stress. So

So something like the sauna, which is a heat stress.

That's something that I started to do in graduate school. So I lived across the street from a gym.

It had a sauna. I started using it every day. And I was using it quite frequently,

probably about five days a week. And I started to notice that I felt really good. Like my mood was

noticeably enhanced. And I also was able to handle stress better. And my anxiety was down.

And I was trying to figure out what was going on in my brain. Like how was the sauna

affecting my brain because it was, it was very obvious to me. So I decided to dive into the

literature and try to figure that out. So most people are familiar with the feel-good endorphin.

What you may not be familiar with is the counter to that, dynorphin. And dynorphin is activated

upon heat stress. And the reason for that is because dynorphin cools the body down. Dynorphin

is the counter to endorphin because it makes you feel uncomfortable and dysphoric. So heat

stress will release dynorphin from a presynaptic neuron and that dynorphin will then bind to

another receptor called the kappa opioid receptor. And when that happens, that's when you begin

to feel uncomfortable and dysphoric. And that's the feeling you usually feel when you're hot

and you're in the sitting in the sauna or you just feel bad and you're like, oh, I just

want to get out, it's too hot, or you're exercising really vigorously, you're

feeling hot and you want to stop, that's dynorphin. That's what's making you feel uncomfortable.

You may be thinking to yourself, I thought you said you felt really good.

What are you talking about here?

This is where it gets really interesting because this pathway, this mechanistic

pathway that is the thermoregulatory control pathway, you make dynorphin to

cool your body down, but you also feel uncomfortable.

What happens is this actually changes the way your brain responds to the feel-good endorphins.

So endorphins bind to another type of receptor called the mu opioid receptor.

And when dynorphin is released and you feel uncomfortable, this causes new opioid receptors to make more of them, and it sensitizes them to endorphin.

So that means the next time that you make endorphin, whether that's from exercise or the sauna, because it also causes you to release endorphin,

or if it's from laughter or giving someone a hug, whatever it is that's causing you to release endorphin,

you are going to feel so much better because that endorphin is going to bind

to those receptors that are really sensitive to that endorphin. And so the effects are lasting and they last longer and you feel better. So it lowers

depression and it helps with anxiety, it helps with all these things when you're,

sensitized to endorphin. And so it's quite possible that this is actually why

the sauna was able to help me deal with my anxiety and help me to deal with

stress and made me feel really good. But in addition to affecting the brain, the sauna

also appears to affect overall longevity. So this was actually a study that came out

Finnish men that were using the sauna frequently. And the study followed them for 20 years and

measured who died of any sort of non-accidental death. So people that died from cardiovascular-related

diseases, people that died from cancer or neurodegenerative diseases, respiratory

diseases. So all these diseases were measured.

These men were followed for 20 years. And what this study found was that men that used the sauna two to three times a week.

They were 27% less likely to die from any cardiovascular related disease compared to

men that use the sauna one time a week.

Men that use the sauna four to seven times a week, they were 50% less likely to die from

cardiovascular related diseases throughout the 20 year period compared to men that only

use the sauna one time a week. So there was a dose-dependent effect that was improving

cardiovascular health and causing these men that were using the sauna more frequently.

Be healthier and to die less of or be less likely to die of cardiovascular disease in

that 20-year time span. Turns out not just sauna frequency was important, but also the

duration of time spent in the sauna. So those same men that stayed in the sauna for greater

than 19 minutes, they have the most robust effect on lowering cardiovascular-related

mortality compared to men that only use the sauna less than 11 minutes. So, both the frequency

and duration of sauna was very important for lowering cardiovascular risk. There are a

variety of different mechanisms that have also been put out there for why using the

sauna can lower cardiovascular-related mortality. Chiefly among them is the sauna in some ways

mimics cardiovascular exercise. So when you sit in the sauna, in a hot sauna, your heart

rate elevates to 100 to 150 beats per minute, which really is equivalent to moderate intensity

physical exercise. Also, plasma volume expands and increases and blood flow increases to

the heart. And this lowers cardiovascular strain. So your heart has to do less work,

for each beat.

That it's pumping blood to deliver oxygen to your tissues. So it's lowering cardiovascular

strain. It's been shown to lower blood pressure, improve endothelial cell function,

endothelial cells line your blood vessels. It's been shown to increase and improve left ventricular

function. So lots of different things that the sauna has been shown to improve in terms of

cardiovascular risk factors. Turns out, cardiovascular disease was not the only thing that the sauna

lowered the mortality rate for, it turned out that all these other non-accidental deaths

were also lowered. So men that used the sauna two to three times a week had a 24% lower

all-cause mortality than men that used the sauna only one time a week. Men that used

the sauna four to seven times a week were 40% less likely to die of cancer, cardiovascular

disease, neurodegenerative disease, respiratory diseases, and all these other non-accidental

diseases that people come down with with age. This is very interesting, but before I get

into the potential mechanisms, I want to point out that this study also measured a variety

of different parameters that may affect the data, confounding factors they're called.

So they measured the physical activity of people, their percent body fat, if they smoked

or drank a lot of alcohol, their socioeconomic status. So all those things were considered

when they were analyzing this data. So this data really is reflective of sauna use. But.

The interesting thing is these men were 40% less likely to die of all these diseases.

Why is that? What is the sauna doing? How is it affecting overall longevity? So to understand

that we're going to have to turn to some animal studies and look at other molecular

mechanisms where we know that heat has shown to affect longevity. Chiefly among them are

heat shock proteins.

So, heat shock proteins, as their name implies, are activated by heat.

They're often referred to as HSPs, and they play a very important role inside of cells.

Their role is to make sure that proteins maintain their three-dimensional structure.

And that's really important because every protein inside your cell has a certain three-dimensional structure in space.

And that three-dimensional structure is essential for that protein's normal function.

And if you disrupt that three-dimensional structure, the protein can't function optimally.

So for example, all your metabolic enzymes are specialized proteins, their three-dimensional

structures are disrupted, they're not going to be working optimally.

That's not the only thing that's important or the only reason why the three-dimensional

structure is important.

The three-dimensional structure of protein is getting damaged all the time.

So just normal existence is damaging proteins in our body all the time.

Every time we breathe in oxygen and we're eating food and our mitochondria are trying,

to couple those together to generate energy.

That generation of energy is really damaging because it also makes reactive byproducts

that damage the proteins inside of our cell.

And when they damage the proteins, the proteins become misfolded.

Their three-dimensional structure is screwed up.

And when they become misfolded, this disrupts the protein half-life.

And what this ends up doing is that protein just sits around inside of the cell longer

than it's supposed to. It's usually supposed to be gotten rid of sooner.

And when it sits around inside of the cell, it starts to aggregate with other proteins

that have been misfolded.

So as we age, we start to get these protein aggregates that accumulate inside of our cells,

outside of our cells, that happens in our brain.

Amyloid beta is probably one of the key protein aggregates that people are familiar with that

plays a role in brain aging as well as Alzheimer's disease.

So these protein aggregates, they disrupt all sorts of things, and they're really, really

bad, and they lead to neurodegenerative diseases. that play a role in cardiovascular disease.

So the role that HSPs or heat shock proteins which are activated by heat is really important because when you have

that protein that's damaged the heat shock proteins can repair that damage and they can make the protein fold back to its

normal three dimensional structure.

And this allows for the protein not to form aggregates.

And that's why heat shock proteins have been shown in many different studies in animals and lower organisms to prevent Alzheimer's-like diseases, Parkinson's

disease, and also cardiovascular disease. So heat shock proteins are very important.

Just sort of as a proof of principle here, there's been a couple of studies that have looked at

fruit flies and worms. These are lower organisms that Temu was talking about, the tardigrade.

These organisms actually share a lot of human DNA. So Drosophila have 4% of these fruit fly genes are found in humans, which is quite a bit.

So if you take a fly and you expose it to one single exposure of heat for 70 minutes,

it extends their lifespan by 15%.

Also, that was shown to be dependent on heat shock proteins because they have a version

of heat shock proteins.

Heat shock proteins have also been associated with human longevity.

So humans that have a variation in a gene that makes heat shock proteins have exceptional longevity.

But there's actually another pathway that's activated by heat, a longevity pathway, and that's FOXO3.

So FOXO3 is a gene that is a master regulator of many other genes because it activates those

genes and it deactivates those genes.

Many of the genes that it's regulating have to do with stress resistance, have to do with

being able to handle stress.

And what do I mean by stress? That same damage I was talking about.

So just the normal damage that we're being exposed to every day, not even to mention

the damage we're exposed to from external factors like benzene from air pollution and

other carcinogens that we're exposed to. That's also damaging things in our body. But that,

same damage that damages proteins damages our DNA. And when it damages our DNA, that

can potentially lead to mutations that could lead to cancer. FOXO3 activates genes that

are involved in DNA repair that repair that damage before it ever can form a mutation.

Additionally, FOXO3 activates genes that are involved in cell death.

So if a cell does get a mutation that could potentially lead to cancer, the cell will

sacrifice itself and it will die.

It's a protective mechanism against cancer.

That same damage that damages proteins, that damages DNA, also damages cells.

And when the cell accumulates enough damage as we age, it accumulates more and more damage,

that cell eventually becomes what's called senescent.

And senescent cells aren't cells that are, they're not alive, but they're not dead.

They're kind of just sitting around inside of a tissue or an organ, and they're secreting

these pro-inflammatory molecules and cytokines that are damaging other nearby cells, accelerating

the aging process and causing them to become senescent.

So it's really bad. FOXO3 activates genes, antioxidants genes, that prevent that damage from ever hitting the cell.

They also, FOXO3 activates genes that if the cell does become senescent and is damaged,

that are involved in autophagy and clearing away that damage.

But just to highlight how important the autophagy process is in clearing away senescent cells,

there was a recent study in mice. Mice also accumulate senescent cells as they age,

and they were given a chemical compound that anytime a senescent cell cropped up in one of

their organs, it got rid of that senescent cell. And that extended the lifespan of the mice by 20%,

so they actually lived 20% longer than their normal average lifespan. So senescent cells are

definitely accelerating the aging process and anything you can do to get rid of senescent

cells or prevent them is going to positively affect aging.

So FOXO3 also activates genes that are involved in stem cell function.

Stem cells are very important because they replace all the other cell types in our tissues.

For example, they make more white blood cells. We lose white blood cells as we age and we become more susceptible to infections and

respiratory diseases as we get older.

Stem cells also make more stem cells, which is good because we lose stem cells as we age

as well. And we want to keep replenishing our organs. We want to keep replenishing the

cells in each of our organs so that they keep maintaining the function of whatever they're

supposed to do. FOXO3 activates those genes as well. It's pretty badass. But if you're

not convinced yet, I'm going to show you a study that's actually my early work when I

was a young scientist at the Salk Institute. It's actually one of the first biology experiments

I did and really got me hooked on biology. So this worm here is a C. elegans worm and

And it lives on average about 15 days of lifespan.

It shares about 60% of its genes are found in humans.

It has a version of the FOXO3 gene.

So this worm has been genetically engineered to express human amyloid beta 42, that toxic

peptide that aggregates and forms plaques and brains of people as they age and plays

a role in Alzheimer's disease.

It's been engineered to express it in its muscle tissue, lower muscle tissue.

So as it ages, the amyloid plaques aggregate in its muscle tissue and it can't move, it becomes paralyzed.

See, it's not moving its lower body, it's just moving its nose around.

That worm right there is 12 days old, so it's at the end of its lifespan.

So the next worm I'm going to show you is the same age as that worm.

It's also been genetically engineered to have amyloid beta plaques in its muscle tissue to get paralyzed.

The only difference is that it's also been genetically manipulated to have FOXO3 gene active all the time.

So you can see it moving around just fine. Same age as the other worm, day 12.

The only difference was that FOXO3 gene prevented those aggregates from accumulating in its muscle tissue and causing it to become paralyzed, so it

aged much better than the other worm. And if,

you're not convinced with worm longevity, then perhaps you'll be convinced with

human longevity. The FOXO3a gene has been associated with human longevity.

We all have different variations of the same gene. So we have the same genes but

different variations of these genes. It's what give people blue eyes versus brown eyes.

Some people have a version of FOXO3a that makes it active all the time. So it's, you

know, it's always activating these antioxidant genes, it's activating autophagy genes, it's

activating stem cell function genes, it's activating DNA repair genes. So these genes

are constantly being activated. And so people that have that are able to deal with all sorts

of damage so much better because they can just repair it constantly. Those people are

are 2.7 times more likely to become a centenarian to live to be 100, which is pretty impressive.

So in summary, when we're talking about the sauna and longevity, the sauna sensitizes

the brain to endorphin, and it does that by increasing dynorphin, which makes you feel

uncomfortable and as a consequence, you feel better because you become sensitive to the

feel-good endorphin. It improves cardiovascular function. It's been associated with lower

cardiovascular rate of mortality, it improves cardiovascular function by lowering cardiovascular

strain. It also improves overall longevity, possibly by many different mechanisms, activating

heat shock proteins, which are important for maintaining the proper three-dimensional structure

of proteins inside of our cells, and also by activating the FOXO3 gene, which is doing

so much cool shit that's like really good and really important for the way we age. One

The other thing that I want to mention that I didn't get into, it also increases growth

hormone by two to threefold.

Sometimes in cases, if you do multiple sauna treatments, it can increase growth hormone by up to 16-fold.

I mean, growth hormone plays a very important role in many things, but improving repair

of muscle damage is one thing that it's important for.

I want to switch gears just for a minute here and talk a little bit about another type of stress or another type of hormetic stress, and that is cold stress, which I think you guys in Finland are also very accustomed to jumping in cold water as well.

There's many different modalities for cold stress, jumping into a cold lake, taking a cold shower, jumping into an ice bath, walking around in the cool air and going into a cryotherapy chamber.

These are all methods that can cold stress our body.

And cold stress, much like heat stress, is a type of hormetic stress that activates all

these genetic pathways that help us deal with stress.

Probably one of the most robust responses to cold stress that I have seen in the literature.

Is the robust increase in norepinephrine in the locus coruleus region of the brain.

In the brain plays a very important role in focus and attention and vigilance, also in

mood. So it makes you feel better. Norepinephrine is something that's actually pharmacologically

targeted quite often. So it's used to treat depression and also ADHD, but it can be released

by cold shocking the body. What kind of temperatures are we talking about here? We're talking about

people that were walking around in 16 degree Celsius air temperature for six hours increased

their norepinephrine by 260%. You don't have to spend that much time in the cold to get a

norepinephrine increase. People that submerged their self in 4.4 degrees Celsius water for 20

seconds were able to increase their norepinephrine by 200 to 300%. So the colder the water, the more

robust the norepinephrine release, but also duration as well. So if you're in less cooler

water then you don't have to stay in as long, for example. But these things have all been

shown to be very robust in releasing norepinephrine.

Something else very cool about norepinephrine, in addition to being a neurotransmitter, it actually

acts as a hormone as well. We also release it in our body because it causes vasoconstriction,

and that's one of the mechanisms that we use to conserve heat when we're cold.

So another mechanism that we use to generate heat is also related to norepinephrine,

and that has to do with increasing mitochondrial biogenesis in your adipose tissue and in your

your muscle tissue. So mitochondrial biogenesis means new mitochondria. The

mitochondrial biogenesis occurs with cold exposure. You can think about it, it

makes perfect sense because as you generate energy as a byproduct you

generate heat. And so this is a adaptive mechanism that occurs to help you warm

up when you're cold. So this mitochondrial biogenesis that happens in

the adipose tissue is often referred to as browning of fat. Also, as you have more

mitochondria and your fat, because fat is where you're storing the most energy, you,

start to burn that fat because the mitochondria are trying really hard to make heat because

they want you to not die, they want you to warm up.

The side effect is that you actually burn fat and so a lot of people like that as a

potential mechanism to treat obesity.

This is all regulated by norepinephrine. So that's very interesting because I just talked about norepinephrine and how it regulates

mood, focus, tension, makes you feel good, helps with anxiety, but it also appears to

regulate this process because if you block the brain's ability to respond to norepinephrine,

then mitochondrial biogenesis does not occur upon cold exposure in adipose tissue.

So that norepinephrine is very important for that.

What kind of temperatures are we talking about for mitochondrial biogenesis?

Those same humans that were walking around in 16 degrees Celsius weather for six hours,

that had a 260% increase in norepinephrine experienced a 37% increase in browning of

their adipose tissue. So they're able to brown their fat after walking around in 16 degrees

Celsius weather, cool-ish weather, for six hours. Adipose tissue is not the only tissue that

mitochondrial biogenesis occurs. The mitochondrial biogenesis also occurs in muscle tissue.

That is not regulated by norepinephrine. That's regulated by another pathway,

but it has been shown to be very robust. It activates something called PGC1-alpha.

And what's interesting is that if you think about mitochondria, they're what allow us to

use oxygen for energy. So if you have more mitochondria in your muscle tissue, then you're

you're going to be able to more effectively use oxygen. And this is why mitochondrial

biogenesis in muscle tissue has been shown to improve aerobic capacity, which, you know,

uses oxygen. So men that actually submerge their legs in, I think it was about 10 degrees

Celsius water for 10 minutes, they experience massive mitochondrial biogenesis in muscle

tissue. The cold exposure has also been shown to improve, in very preliminary studies, to

improve endurance in some athletes, including runners and cyclists and tennis players.

So there's the ongoing study looking at how cold exposure may actually enhance endurance

performance because of this mitochondrial biogenesis, among other things, it also reduces

inflammation helps with recovery time.

Lots of interesting stuff we've talked about today. We talked about how the sauna affects

cardiovascular function, how it affects overall longevity, how it affects the brain,

how it sensitizes the brain to endorphins. Talked about how it activates FOXO3 and how FOXO3 is

a really important stress response genetic pathway that activates all these other amazing genes that

help us deal with all the damage that we're constantly being exposed to and how it's

it's involved in longevity. We talked about cold exposure and how it's important for norepinephrine, how norepinephrine helps you focus, it helps

you feel good, and also helps with anxiety as well. And it causes the

production of new mitochondria both in your adipose tissue and cold causes the

production of new mitochondria in your muscle tissue and how that may play a.

Role in endurance. Lots of interesting science going on in this field, but what

I think many of you actually may be asking yourself is what about going from

the hot sauna into the cold water, does going into the cold water after the hot sauna negate

any of those effects? And the short answer is, I don't know. There's not really any empirical

evidence that I've seen that suggests anything because no one's really looking at that. But

I do know that going from a hot sauna into the cold water causes norepinephrine to be

increased even more than either alone. So that's good. It implies there may be some

synergistic effect. And I also know that cold shocking the body with cold water, whatever

modality you're using, also activates heat shock proteins, not as robustly as heat does.

But the fact that it activates the same genetic pathway that heat does, I think is good because

it gives us hope that maybe these two things in combination are synergistically acting

together and are improving overall longevity through similar mechanisms. But I know personally

from doing it, it also just makes you feel really good. And I think that counts for something.

So with that I will say thank you.

Thank you, Dr. Rhonda Patrick for providing such an amazing summary on the health benefits of regular sauna use.

Here are the top five health facts of the day about regular sauna use based on latest scientific evidence.

Number one, multiple studies have found that regular sauna use can improve cardiovascular health and reduce risks of,

cardiovascular events by reducing blood pressure, improving blood flow and increasing heart rate.

Number two. Sauna use can improve cognitive function and reduce the risk of dementia as well as Alzheimer's disease.

Actually people who use sauna four to seven times per week had about on average.

65% lower risk of developing these conditions compared to those who use sauna only once a week.

Number three. Sauna use has been shown to improve athletic performance, muscle recovery, increase endurance and reduce fatigue.

Fatigue. Sauna use can also improve respiratory performance, including reduced symptoms of

chronic bronchitis and asthma. Sauna use can help clear airways, reduce inflammation and

increase lung capacity.

4. Sauna use can boost the immune system by increasing the production of white blood cells

and improving the body's ability to fight infections. Sweating in a sauna can help eliminate

toxins and impurities from the body through the skin. This can help improve skin health

and also aid in the elimination of heavy metals and other toxins from the body.

Number five. Sauna use has been shown to promote relaxation,

reduce stress levels, improve sleep quality and promote deep sleep.

It increases the production of endorphins and reduces the levels of stress hormones.

Just make sure that you don't use sauna too close to bedtime,

as it can keep the heart rate elevated and affect the sleep architecture.

Now, those are just some of the few benefits of regular sauna use.

There is many more and we will be happy to share more in future episodes.

So thank you very much for joining us for this episode. To learn more about us and biohacking, check out Biohackercenter.com,

where you can find best content, supplements, technologies, courses and events

such as the Biohacker Summit, so that you can take the guesswork out of how to champion

healthy habits, prolong your health span and lead a productive life.

Thank you very much and see you in the next episode.