Psychiatry & Psychotherapy Podcast - Cold Exposure for Mental Health

Episode Date: January 17, 2025

Can cold exposure improve your mental health? In this episode, we explore the science behind cold therapy methods like ice baths, cryotherapy, cold-water swimming, and cold showers. Backed by research, we dive into the physiological and psychological effects of cold exposure, including its impact on mood, anxiety, dopamine, norepinephrine, and stress resilience. We discuss historical practices, benefits for mental and physical health, and common misconceptions around claims like immune boosting and inflammation reduction. Learn practical tips, safety precautions, and how cold immersion could fit into your mental health or wellness routine. Whether you're curious about the Wim Hof Method, the dopamine-boosting effects of cold plunges, or the latest studies on cold exposure's antidepressant potential, this episode offers insights you won't want to miss.   By listening to this episode, you can earn 1.5 Psychiatry CME Credits. Link to blog. Link to YouTube video.

All right, welcome back to the podcast. I am joined today with Liam Browning. He is a return guest to the podcast because of his deep desire to be willing to dive into topics of my, I guess our interest, my interest. This one was more my interest. Today we'll be talking about cold exposure. It's a practice of immersion into ice baths, cold plunges, cold water swimming. cold showers, cryotherapy, which has surged in popularity. I remember I watched the Wimhoff documentary, and you watched these guys visiting Wimhoff, and I had never been in a cold immersion when I watched this thing, and you know, you're watching these guys jump into ice-cold waterfalls, and you're like, I don't know if I could do that. You know, where they go on this, like, super long hike in the Arctic cold freezing,

and they're in the sauna and they're in their back in the cold and then they're in the sauna and then back in the cold and you're like, what is this? And then all of a sudden everyone starts talking about it. So I got interested in it a couple years ago, built my own cold plunge, went out this morning, did four minutes at 42 degrees Fahrenheit just because I knew I was coming on, you know?

Yeah. You had to say that you've done it so you can talk about it. I had to re-experience it. And, you know, I've recommended it to a couple patients who have had good results. We're going to talk about this day. We're going to go through every study. This will be the most comprehensive audio article out there, I would say, at this point. And we've looked at other podcasters, famous ones, that have talked about this.

But we will go study by study. What is currently known? What is not known? we were even talking yesterday me and Liam about like, man, we should raise some money to study this and do a really nice

randomized control trial because there is really nothing. No. Nothing at all really. There is no really nice randomized control trials that we can find. And we'll talk about all of them.

And, you know, it's kind of like the ketogenic diet for some people. It's like they swear by it. not very many of my patients will do it right i've you know it's kind of like off label it's got its own risks we're going to talk about those as well but you know on this podcast we really seek to look at things that may work you know there's a lot of things we don't cover like be stings

probably not going to work uh homeopathic remedies not going to work right just diluted water. Sorry if I offended you. I can give you some empathy if you come to me for therapy. Okay. So Liam back at it recently engaged. Yep. Thank you. So excited to see those pictures. Yeah, I'm so excited. Yeah, you'll be at the wedding too. So don't worry. Yeah. Liam told me I'm going to officiate the wedding. We're going to live stream it on Instagram. That's a joke. No, I'm just happy to be there and celebrate you and celebrate, man, there's so many of my patients that want to be happily engaged, happily married, and it is a tough dating landscape right now. Yeah, it's really tough out there. And I feel for them. A lot of my friends are going through it. So, yeah, it's really

tough. I just want to say, yeah, thanks for having me back on. It's always a pleasure to dive into some of these topics together and really follow our curiosity about, you know, what's been going on in the mental health sphere because this is really a practice that's talked about by so many different podcasters, so many different social media influencers. And, you know, they're making all these claims about how it's beneficial for the mental health, like helping them boost mental clarity and all these different claims. So I just really wanted to dive into this with you and it's been an enjoyable experience so far. Some say the best thing about cold plunging is telling other people that you're cold plunging.

Yeah, exactly. You get to put it on your Instagram story and your Snapchat. It's like, look at what I did. Look what I did. I woke up at 4 a.m. did my cold plunge and did it run while you're still in your warm bed.

That's like the ethos behind it, I feel. Liam came out to my house and he got to cold plunge at my house. And it was like, it was one of your first ones, right? Yeah, that was my first time. That was your first time. Okay. And what was that experience like?

Oh. It was an immediate shock. Like, I've done cold showers before, but I don't think anything compares to getting into water that is, like, ice cold. Like, you immediately just want to get out. Like, it's so cold. And I think yours is especially cold, too. Like, you've got the whole setup.

So the water is constantly circulating, too. The water is circulating. That really takes, because normally when you're in cold water, you develop a little bit of a barrier eventually. that's why like the first 45 seconds are the hardest but if you have it constantly circulating the areas that are circulating are so cold i think you did a full five minutes yeah i did five minutes it was pretty intense like i probably did it a little bit more than i should have because it was my first time but i wanted to get the true effect and yeah it definitely was a shock at first but you kind

of ease into it and i end up being really calm and relaxed after so i can definitely see you like why people would think that it's beneficial. There's some days I come home and I'm like, it's the haze of war. You know, I've talked to patients about trauma, you know, hours of different therapy sessions.

You know, I usually do about eight and a half hours a day on a full day. And my wife will be like, can you go a cold plunge? Like, because afterwards my brain just comes back online, you know, it's like,

it just wakes up. Right. Really, really, like, it's a shock to the system. Yeah, so let's talk about the different forms real quick. Cold water immersion, usually around 40 to 60 degrees Fahrenheit. That's 5 to 15 degrees centigrade for 2 to 15 minutes.

I would say 15 minutes. You cannot do 15 minutes comfortably at 40 degrees. Like when you're around 40 degrees, just for my experience, 5 minutes, 7 minutes, you're good. The really dark studies from Nazi Germany, they would they were trying to, they would stick people in the ice cold water, see how long they could live. 45 minutes for a lot of people around that time. So, you know, 15 minutes is pretty pretty extensive. Yeah, I think that's for some of the more warmer temperatures. Because we'll get into some of these studies, but one of them, it was like 60 degrees Fahrenheit, and they were in there for an hour. So, I mean, it's like almost the temperature of a colder pool.

It's like we also, when you visited, went to a spring. It was like, it's like 65, 66 degrees all year, which is why in Florida, it's like a total amazing place to go, right? Yeah. But yeah, you'll be in there for an hour and you won't think about it that much. But I, and that's why I'm like reading these studies and I'm like, oh, can you guys go a little bit colder for even that, for that five minute, six minute time period? Because that seems to be like that sweet spot for me. There's cryotherapy, which is two to four minutes at,

166 to 220 degrees by negative Fahrenheit. Now, you know, we can't even think in terms of how cold that is, like in terms of our normal understanding, but you have to realize that conductivity is totally different than water. And I've had friends who have done cold plunging with me and done cryo, and they say that the cold plunges is a lot harder psychologically. Exactly. You know, 25 times more basically conductivity with water compared to air. Okay. And I think when you have circulating water is probably, it's probably even worse because you don't have that like thermal barrier that develops. So, yes, there's cryotherapy. But we have some studies on that we're going to talk about because there actually have been some talk about cold showers. So some patients will be like, can I just take a cold shower? And I'm like, you're in Florida. Then nothing is cold here. It's like the water comes out at 75 degrees.

That's not cold you need to go to. There's a place around here. It's like some Y MCAs. There's some different gyms that have cold plunge, sauna. So I'm like, just go to one of those and try it out, see if it's helpful. And then there's ice baths. Just putting ice into your, like, put the water as cool as you can, add some ice. I did this.

This is how I started. Did this with my kids. start out with like 30 pounds of ice, worked our way up to about 50, 60. Wow. And then we'd have some friends over and do it together and kind of a fun experience. Was like the whole bath ice? No, or is it with water too? Yeah, with water, mostly water.

50 pounds is not that much, actually. Yeah, because a lot of athletes, they use the ice baths, like an entire tub of just ice. And that's like, it's not as cool because there's some pockets of air in the ice. Yeah, I think Wimhoff has been in pure ice for like, what? I think it was like a couple hours or something. Yeah, it was hours. Yeah.

And so it's a lot easier because essentially there's very few points of contact with your skin, especially if you're using the right type of ice. And then essentially you're just in cold air and then the water drips down. Yeah, so impressive nonetheless, 12 hours is insane. It's impressive. Yeah. It's not, like the Guinness Book of Records is not fun in my mind for heat or cold. No, we talked about the heat one where they're in a boiling hot sauna.

And, you know, it's just crazy how much the body can withstand after it adapts the stuff. They stop, they stop doing it so hot after some people passed away, unfortunately. But they were doing like six or seven minutes at like 230 with steam. There's wild. And then, you know, there's a video I saw of the Iceman, Wimhoff, swimming under ice water for like 50 yards. It's like, oh my gosh, because I put my head underwater for like 10 or 15 seconds and I start getting that like freeze pain, you know? So I can't imagine. Now he's a beast.

Okay. So the history of cold therapy. Do you want to talk about this at all? Yeah. So this is a practice that kind of goes back, at least what I was able to find to like Greek and Roman times, where we talked about before, they had these these hot bath houses. And they also had some cold water in these houses too with ice, apparently. And, you know, this is also something that Hippocrates and Galen, like these physicians in the back of those times, they espoused the benefits of cold water for the use of fever and Galen, the Roman. physician, he actually started using ice to stop bleeding. So even then, they could observe that there was some vasoconstrictive effects of cold. And, you know, those practices, it's kind of gone out of favor with more Western cultures, like in the Americas, but it's been continued through the

Nordic countries, like Denmark, Finland, and so on. And where there, it's used as kind of like we talked about the hot and cold therapy where they go from a sauna into the cold plunge and then back into sauna or it's often used as like a way to finalize yourself after work like in denmark there is a pretty big culture around ice water swimming where they go out into the sea after work and they all meet up and then they go plunged the water swim around for a couple minutes and then they hop back in and they continue on with their day so it's it's really a practice that's ingrained into the culture and it's starting to get picked up now by like these podcasters and social media influencers. So a lot of people in America are starting to do it.

Yeah, and I, you know, we looked at this study, the Ku Piochemic heart disease study, which was discussed on episode 221 on sauna, basically. And there was a cohort of Finnish men that they followed for decades. and they found that those that used sauna you is the sauna four to seven times per week had huge reductions in significant medical issues you know 62% lower risk of stroke 66% decreased risk of dementia 37% lower risk of pneumonia 78% lower risk of pneumonia 78% lower risk of psychotic disorder. Okay, there was a decrease in all-cause mortality.

Compared to the people that were using the sauna one time a week. Interestingly, in Finland, there is no zero time per week control in the cohort because everyone uses the sauna roughly one time a week. So I was thinking about this and I was like, well, how often are these people using cold exposure as part of their thing? Because a lot of the times they'll talk about like how they do hot, cold, hot, cold. cold hot, cold hot, you know, usually they finish in cold. So I emailed the authors, we haven't heard back, but we did a search.

And it's pretty usual to end with either a cold shower, a cold dip, and a lake. And so one of the things that wasn't controlled in this study was the use of cold and how that impacts the overall physical, mental wellbeing as well. Right, and there's really no epidemiological studies looking at this practice, which I think that's somewhere that we could start with pretty easily for looking at the mental benefits of cold. And I think, yeah, we'd have to look at some of these Finnish cultures who use a practice more regularly compared to, like, in the U.S.

where now as many people use it. So, yeah, I mean, it's definitely a practice that's more common there. So there could be some benefit to it that you can attribute some of the benefits of sauna potentially from this study. There's a big, large winter swimming society out there, you know, 100,000 members type of thing. So this is something that in the U.S. is just completely unknown. So it's like we're discovering it. No, we invented it in the U.S. is kind of how we feel, don't we? They didn't discover this.

We are the ones that are discovering the sauna, the coal plunge. The thing is, is that, you know, in Florida here, there's no cold water. Like, you have to create your own. So I, like, bought this large cooler, and I hooked up. I spent several weeks kind of designing this thing, built a pump with a filter, and then it goes through like a refrigerating device and back to the thing. Otherwise, you have to spend like five, six grand on it, which is so expensive. Right. If you don't have access to like a cold lake, then you're not, you don't have like an easy way to do it. Whereas like in these Scandinavian countries, everyone is outside. Like they have easy access to a lake. And like the, I think that one of the main differences between cold plunges here versus there is that there is more of like a social practice. Like they use it all to relax together or they do it like after work like I mentioned in Denmark. Whereas here it's more so like individuals. Like I do the cold shower.

by myself, then I get out with my day, or like, I do the cold plunge. So I think there's less availability for that, the social aspect, at least in the States. Yeah. And I, I built a sauna, and so next time you come out here, you're going to have that group aspect. I don't know, I think there's something about that that's fun. You know, it's like four people come over, cook and a sauna together, go to a cold punch. I'm like, okay, follow the data, right? Okay. So what is happening to the body during cold exposure. So there's the bottom up signals, and then there's top-down signals. Talk to me first about the bottom-up signals of the body, you know, of getting in.

The bottom-up signals are like the signals from the body, essentially telling us that we're in shock, like we need to do something to get out of this situation or scenario. So that first starts with the thermoreceptors on the skin, detecting the rapid temperature drop. And then this eventually leads to activation of sensory fibers in the spine and then up into the hypothalamus that detects the temperature change. And this rapid temperature change, again, tells us that we need to move and to get out of this situation. So this activates the sympathetic nervous system. Adrenaline is involved here, norapherin or noradrenaline. They're released from the adrenals in response to the signals from the hypothalamus and the sympathetic nervous system.

And at the same time, we also get activation of the HPA axis. And then this also continues the release of noraphynephrine into brain too. So in the brain, these are the top-down signals. Even before we start doing the cold plunge in anticipation of the cold, like we see the cold plunge in front of us and we kind of have to hype ourselves up to get into it. So that's like already activating parts of the brain telling us this is a scenario that's going to be dangerous to us. So these parts of the brain, like the prefrontal cortex, the insula, the amygdala, they're processing, the relative danger it is to us. And all these circuits, they converge onto the anxiety centers in the brain, the salient centers, and these will then go on to activate the hypothalamus once again and to increase the release of corticotropin releasing hormone, which is the first hormone of the HPA axis and is also a neuromodulator, increases apteated with the enigdala.

And then also the part of the hypothalamus that releases, CRH, will then activate the locus serulius, which is the brain's main storage center for the noroprenephyran. So in effect, even just from looking at the cold and anticipating it, you have a psychological response that activates the sympathetic nervous system as well in the HP axis. Yeah, and it's interesting how when this happens, you know, that amygdala response the locus serelius, released in the norbinephrine, that fear response, I mean, you gasp. Like there's a gasp reflex where you, they're just,

and actually that gasping is what usually leads to people breathing in the cold water. Like if they, when people break through ice and they hit cold water and that gasp reflex is so strong. Other things that can happen, the vasoconstriction, blood vessels, right, on the skin, contract so that you're not like releasing a ton of temperature out nerve conduction slows in the cold leading to a reduction in pain and sensation eventually the heart rate typically increases if if there's a lot of fear but i would say from experience it actually drops for me quite a bit so if i'm coming in from a workout my heartbeat could be around like 95 i get in and

it drops 20 to 30 beats almost immediately. There can be a little bit of an increase in blood pressure. There can be this rapid, shallow breathing, which I think is why the Wim Hof breathing is this kind of like, you know, they'll start fast and a lot of breathing and then they'll hold their breath when they get in. There's different ways of doing it. But essentially, this is a great time to do slow and like long breaths

to practice that. and that is a way like sometimes I'll just count my breaths the first 20 are the most painful and just slow long breaths and everything you need doesn't want to do that but that helps you regulate the stress response yeah so interestingly norpidephren increases two to threefold and remains elevated for hours and we're going to talk more about this but i think that may be part of the mental health benefit, right? Right. We think about like medications that increase the nophenephydrin often have to do with

focus, concentration, sometimes for depression as well. Serotonin, norapherin reuptake inhibitors, right? There's that norepinephrine reuptake increase. Now there is a slight difference. We're measuring, we're measuring blood levels of norepenephrine, measuring peripheral. Right. With their patients, yeah, we're not measuring the epinephrine in the brain or noraphenaphrin in the brain from SNRIs. I mean, the SNRIs are more specific to the brain as well because they're inhibiting the re-uptake at the synapse and not causing like a dump of noraphenephrine from the adrenals like you see with the cold shock response or other stressors.

Yeah, so I think that we'll get more out of this. Cortisol increases, but may over time you make it more used to it. so your cortisol may not increase. And shivering occurs when your core body temperature drops. And I would say it's pretty rare at this point for me to shiver at all when I'm in there. But when I get someone new, they're shivering within a couple of minutes. And it's very visible. Yeah, I was shivering a lot when I started, even like for minutes after.

I got so cold. And I'm so many shivers a lot too. Like I did the cold plunge back when we, when I got proposed or when I got engaged, we went to a resort that had the hot and cold. And even in the cold, I was shivering, even after the sauna. So if you're not used to it, you're going to shiver a lot. Oh, I had this friend over and we were slacklining. And in between slacklining, we were going to the cold plunge, right?

And I didn't realize he was completely naive. to it. And we ended up doing about 20 minutes because it was hot out. So we do, it was hot, you know, slack lining for like 10, 15 minutes, getting the cold plunge for like one minute. Copy, repeat. I ended up hurting my foot, my toe, and it's still been hurting months later. So I think I couldn't feel how maybe the micro damage from the slack lining because of the cold, but that it kind of caught up to me. So. I felt bad for him after I realized he had never even done this before, and I was, like, subjected him.

His willingness to do it was always there, so it was not. Torture. Torture would be awful and cold, honestly. Like, if you didn't choose to do it, like, I could never do this to someone who wasn't wanting to do it. Like, they would have to, there has to be full, like, agreement that, yes, I want to try to do this. right and we'll kind of get into it but i think that might be part of the benefit is you want to do this

and pushing yourself to do it yourself is probably where the benefit comes from i think that this is why it would never work to test animals in cold and to see how like their neurotransmitters or different things are increasing or because it's like that you're essentially torturing that animal right and so you're just getting good even just touching the animal like handling animals like mice, you see a really profound sympathetic response, a stress response. So yeah, I don't think this really lends itself to starting in animals. Yeah. Okay, so cold water swimming. So cold water swimming, there's a, there's a book I read Winter Swimming by Susanna Soberg. She's popularized this. She did some research on brown fat. We're going to talk about this. Any thoughts on this,

Liam? Yeah, I just want to mention like the initial step. for cold water swimming. Most of them are like observational studies of people in Denmark, and that's where Dr. Sober is from. And, you know, some of these initial studies were promising. Like they showed some improvements in people's metabolism, like triglycerides, glucose, even cholesterol, their quality of life, well-being, their mood,

some anxiety and depressive symptoms. But again, most of these studies were just observational. seeing someone how they changed from October into April. And obviously there's a lot of confounding factors that go into that, like the effect of exercise, the effects of socialization, and maybe even a healthy user bias. Like if someone starts to do a practice that they perceive as healthy, then they also change their other behaviors too.

Then there's also the effect of being in nature because that's where most of these studies were conducted out into the sea. and there is some mental health benefits to being in nature as well. So I think a lot of the book does draw on these initial studies, and I think what's important is that we look at the actual effect of how most people use cold plunges today, and that's through doing it passively not so much in nature, but it's more so just the physiological response to cold itself that might be, that we can look at a little bit easier with some of the,

studies. So I think like with the cold water swimming studies, there's just too many confounders to make any really solid claims about. Yeah, it's like there's a lot of positive things that they show, but is it the swimming? Yeah, is it the group socialization? Yes, and, right? It's probably all of the above. So it's hard to isolate it. Also, not everywhere has the capacity to have the cold. a couple things I would mention if you're listening to this is don't do this alone you know yeah it's not a good idea to go cold water swimming alone you want to go with someone who's experienced who can rescue you if you have that shock response when you get in the cold you may want to ease your easier way into this experience so there's my disclaimer okay shall we talk about this

Kelly and Bird 2021 improved mood following a single immersion in cold water. Yeah, so this study, they looked at a group of participants,

42 of them. This one actually took place in the sea in the UK in November. So the water temperature is about 56 degrees Fahrenheit. And of the participants

who went in, about half the group, they went in the cold water and they saw improvements in the mood, marked by increased vigor, increased esteem, decreased tension, decreased anger, decreased depression, decreased fatigue. Whereas the control group, they actually increased in depression by one point.

So I thought that was kind of funny. But yeah, so they saw some positive moods. This is 20 minutes. It's 56. So it's not very cold. 56 for me in terms of what I think. 20 minutes is long, though. And also the maximum score for these subscales range from 16 to 32.

So a two-point decrease on a 32-point scale is not huge. It's not incredibly exciting. This is a very easy study to do because it's like you have this experience, you rate them before and after, boom, you have your data, right? All right. It's a good preliminary study. I think this study says, look, these people aren't going to,

no one died in this study, okay? they were able to get people to stand in water for 20 minutes in this study right it was like a field trip to the lake or to the sea and then everyone jumped in and they saw what happens okay let's go on to the next one yanco slovaka at all 2003 short-term head out of whole body cold water immersion facilitates positive affect and increases interaction between large scale brain networks Yeah, this study also used somewhat warmer water temperatures. They used 68 degrees for five minutes, and there were 33 participants who did this, and they observed immediate improvements in positive affect, and also detraces a negative effect according to the PANS scale. And this is about five points each, so again, not too much of a difference for this scale. And they also correlated some of these changes with changes in brain activity and fMRI,

specifically coupling of the medial prefrontal cortex with the anterior insula and the dorsalateral prefrontal cortex decreases coupling with the medial prefrontal cortex and the anterior cingulate cortex. So to me, I think these brain imaging findings tend to be a little bit nonspecific. Like, of course, putting yourself into like a shock experience is going to change your brain activity, but I think the specificity of those changes, I mean, if you do another study similar to this, you're probably going to see different brain changes. And then, of course, you can correlate that with the changes in mood. So I'm not sure how much to weigh into these brain changes.

I actually wrote the author on this and I asked some questions. And she said, the overarching finding of this study is that a five-minute whole body cold water immersion changes functional connectivity in the brain. These changes are associated with changes in an emotional state as follows. Focal, strong connectivity between frontal and parietal parts of the default mode network, M-PFC and LP salence network, especially interior insula, which contributes to pro-preceptive feeling, attentional networks as an indicator of alertness, and posterior part of the executive network, which is controlling. decision making. Increasing this focal connectivity may explain the positive effect of CWI.

Self-reported positive effect had a strong correlation with increasing this focal connectivity. Distributed weak connectivity between multiple brain networks was also seen. Self-reported reduction and negative affect was associated with the distributed again equals weak pattern of neuroactivity. Why is this important? We do not want to see focal connections associated with negative affects. Typically, this would mean increasing in symptom severity. Thank you, Alla, for responding to me and giving this kind of thoughtfulness, thoughtful reply here. So we'll include this in the handout.

All right, let's go to Read at All-2020. Cardiovascular and mood responses to an acute bout of cold immersion. So this is 16 adults immersed for 15 minutes and 50 degrees Fahrenheit. So that's more legit now. That's getting there. That's legit. Water up to the sternum, I would have liked to see them cover their jugular, you know, the neck because of all the sympathetic nerve and stuff, yeah.

So assessments were connected pre-immersion during immersion, which is about one minute and 15-minute time points, and 30 minutes post-emerission and 180 minutes post-emerasion. So tell me what they found. They found this was using the same scale as a previous study that negative affect decreased, but only after 180 minutes post-adversion. And it didn't change immediately during immersion. and also positive affect did not change. And then looking at this box plot of the charts with each individual data point, it looks like there was one individual who had like a really strong response.

They had a high amount of negative effect prior to the immersion, and then after their immersion, 10080 minutes later, they had a reduction of that negative effect. I think a lot of that drove some of these, this statistically significant finding. So I'm not really too sure how strong that this effect is for negative affect. Once again, this is a one-time event, right?

And I think it's possible that this is like, from my experience, it may not be the first immersion that you get the benefit for depression. It may take repeated and ongoing immersive. experiences. Yeah, I'm not sure how willing this participant was.

If they had this much negative affect prior to the exposure, they're probably a little bit nervous about it. It might have been their first time. Things are trending in the right direction, right? No changes in beta endorphin were observed. That's interesting. Yeah, then cortisol was also not changed for the first 30 minutes, so prior to immersion and then 15 minutes after the immersion.

And then it actually decreased by 47% after 180 minutes. I think that's really impressive. That's a big decrease 180 minutes after. Now, that makes me wonder, even before doing the experience, did they have a little bit elevated cortisol because they were stressed out about going into the water for the first time? Yeah, exactly. I think there's probably, that's probably part of the effect that explains it.

Yeah. Okay, the catacolamine hypothesis. Walk me through this. Yeah, so this is really, in my mind, some of the most robust findings that you see from these studies looking at the physiological changes, and we know that catacolamines are associated with moon. So catacolamines being dopamine,

neuroprenephrin, epinephrine. And the first study that really demonstrated this to a pretty profound extent was by ceramic at all in 2000 in the study titled Human Physiological Responsive to Immersion into Water of Different Temperatures. So in this study they had 10 male subjects sit in a chair and different temperatures of water for one hour.

And that sounds pretty incredible, but the temperature again was about 59 degrees Fahrenheit and then there was another condition, 68 degrees Fahrenheit and then 90 degrees Fahrenheit, so almost like a hot tub. And then they measured the, different cataclymine amounts and cortisol and they found that the coldest water temperature it actually led to hypothermia to some extent they dropped 37 degrees Celsius to 35.6 degrees Celsius

and this increased metabolic rate led to an increased heart rate and blood pressure changes so an activation of the sympathetic nervous system and they observed plasma norepinephrine and dopamine they both increased five-fold epinephrine remained unchanged, and then they also observed plasma cortisol decreases in each session. So even in the control sessions, I think this is kind of tying back into the previous study how cortisol decreased. Corosol seemed to be a little bit elevated

in all of these different trials, and then they dropped within 120 minutes, and its highest prior to the coldest condition, and this might be related to the psychological distress, like thinking, oh, I'm going to be in the cold water for an hour that's pretty intense. And you can see that this group had the highest cortisol was prior to this exposure.

So it might be a psychological-based increasing cortisol and then later normalized as they calm down. Yeah. I think what is most interesting to me here is that the norpeneverin and dopamine increase. fivefold. Now this is peripheral. It's not like we're autopsying people's brains. You know, like, so this is peripheral, norpeneverin, peripheral dopamine. Yet, you know, we have a lot of meds that increase norpeneverin and dopamine for focus, for depression, for anxiety. And so could this

be impactful? I think it does help me focus better. I think it does increase my ability to like engage and zoom in, you know. I had one patient who would take some amphetamine salt in the morning. And then instead of taking one in the afternoon, because it would give him insomnia, I convinced him to do a col plunge. So he started cold plunging around 1 p.m. And he said that's helped him continue to computer program and study. That made all the difference. So there's one antidotal, you know, person. It's a case report right there. Case report.

So meanwhile, a more recent study, Elmont et al-at-all, 2021 showed that noraphenephrine, epinephrine, and cortisol can increase with shorter cold plunge sessions. In this study, 12 young men sat in 59 degrees Fahrenheit water, 14 Celsius, 14, for 10 minutes, cortisol, norbinephyran, epinephrine, were each significantly increased and remained elevated for several hours after immersion. This is not that cold.

I'm not impressed. I want studies with 45 degrees Fahrenheit. That's what I want. Yeah, so I thought, like, the most interesting thing about this study was that the norprodeferin, epidephrine, and cortisol remained elevated.

And this effect is like, most strong, like in norpenephyran. I put some charts here from the study and you can see it's far and above the control group and it remains elevated for about two hours at least.

Let's talk about this. Leppalooto at all, 2008. I'm sure I'm butchering that name. I apologize. Investigated the effect of repeated cold exposure over 12 weeks in 20 female participants.

comparing three times per week cold water swimming. This was zero to two degrees Celsius. So this is getting... So this is the cold temperature now. This is... Not freezing. Like 32 degrees Fahrenheit, like 36? For 20 seconds,

cryotherapy for two minutes. Cryotherapy was negative 110 Celsius. The study found that plasma norbinephrine increased two to threefold, acutely for each session for the above interventions, and this effect persisted throughout the 12-week period. Interesting. Yeah, so even after the participants became habituated to the cold water

or the cryotherapy, they still had this increase in neuropinephrine after each of the sessions. And the same cannot be said about cortisol, where cortisol initially peaked during the first two weeks on the days that they expected to do the cold plunge compared to the control days. These were elevated only for the first two weeks. Then after that, what I think, like, you can probably explain either due to psychological mechanisms or physiological, that they became habituid to the cold, and then they stopped having this cortisol response. Interestingly, in this study, plasma, like IL1, beta, IL6, TNF Alpha, did not show any change after cold exposure.

So these are other inflammatory markers, bad markers. One of the biggest claims about cold exposure is that it helps the immune system and it can reduce inflammation. And these are some of the main inflammatory markers that are used in most studies and this study didn't find any effect. Which it's not like I would want this to increase those, you know, drugs that increase. TNF alpha tend to not be very good for mental health. Right.

So, yeah, tell me about the next study. So this next study was one of the first RCTs. They actually did one study prior to this with non-active controls, and they saw a benefit. But this was by RimaZuska at all in 2020. So they looked at 92 patients with mild to moderate depression, 17 points on average. and the HAMD in 21 to 24 in the BDI, and they were receiving outpatient therapy. So the participants were randomly allocated

to the cryogenic temperatures, which was a negative 110 degrees Celsius, which I think is like negative 160-something Fahrenheit, and negative 135. So they were exposed to either this or to non-cryogenic temperatures in the cryotherapy machine. So this was an active control.

And they did this for two weeks, and they did 10 total sessions, so for about three minutes each. And they found that both groups improved on the depressive symptoms of Hamdi and BDI. And after one week of the treatment, the prior therapy group scored on average five points lower on the BDI compared to the control group. But the next week, both of the groups essentially caught up to each other. And there's no difference at two-week follow-up. But there were some elements or some subscales of BDI that did improve more. more in the cryotherapy group, such as sadness, loss of pleasure, self-criticalness,

loss of interest in decisiveness, and lower scores on the cognitive affect dimension and the somatic dimension too. And then they had higher improvements in quality of life and symptoms really to pain, sleep, and self-acceptance. But again, for this side, there's also no changes in systemic inflammatory markers like CRP, IL-6, IL-10, and oxidative stress like nitrogase, So how much of a decrease in the BDI and in the Hamdi? So the first week, they went from 23 on average in the experimental group, the crowd therapy group, from 23 to 9.4, and then the next time point, the second week, they actually went back up to 15. And then after two week fall out, they're at 13. See, that's a huge initial decrease.

that's like that's like really significant yeah which which makes you think like okay maybe there's a role in like just snapping someone out of the funk maybe it's you're going to need therapy you're going to need other treatments but to get someone from a 21 to a 9.4 that quickly is it's pretty significant yeah that's actually huge and i had a patient who's around 70 male and he said he's been depressed. He's not talking as much. He's normally very social. And we decided to do the sauna cold plunge. He didn't want end therapy. He was already exercising. He had an immediate change. It was like day one. He was like, whoa, I feel totally different. My wife notices a different week one, he comes back. And he was like a totally different person.

you know and he's he was what i would call like a total responder i mean no medication i mean maybe you could say it was my one hour of therapy i did as well but no i think i think it was a maybe a combination but yeah first first week he was doing it every day he was going in the cole plunge for like one minute heat for two to three minutes go back to the cold blanche one minute i mean this is an older guy. And so yeah, that's a big, that's a big initial drop though. Yeah, I think it really does have an effect on really pulling someone out of a mental state that they're previously in, kind of like exercise. Like, if I, if I don't exercise in a day, then I feel a little bit jittery. And I'm sure like many people feel that way too. And,

you know, I think once you start to do something like this, if it changes your mental state, then even if it's like volunteer or not, like it probably is going to have some effect. And sometimes it can be positive. Sometimes it might be negative. Yep. Okay. Yeah. Anything else interesting about this study?

No, but I just want to say like broadly, the most profound physiological thing is that we see an increase in noroprenephrine. And even though we're not measuring it in the plasma, or we're not measuring it in the brain. We're measuring it in plasma. and norophenaphrin doesn't cross the blood-brain barrier, that there's probably an increase of noroprenephyr in the brain. And, you know, the extent to which this is important, I'm not sure. But we know the exercise also increases noroprenephrine.

Some of these medications do as well. So I think it is going to be interesting to look at, you know, what is the actual utility behind this? And does that explain a lot of these mood benefits that we're seeing, or is it more so just like a change in someone's psychological response and changing their mindset, like I mentioned. Yeah, doing something. Like, doing something hard, it's probably going to, it's like a behavioral therapy, right? Right. Yeah. Let's talk about inflammation and immune functioning. Yeah, so, like, these studies weren't

seeing any positive benefits on the inflammatory response. Like, they're not, they're seeing stable inflammatory cytokines. But this is kind of like one of the main claims about cold exposure is that it does change the immune system. So at this point I'd say like it's probably not so much the mood benefits are due to reduction in inflammation, at least at this point I'd say. But you know, some initial studies did show that people who did cold exposure had 40% less upper respiratory infections. But again, this was like one of those cold water swimming studies and it was self-report. But I think one of the more interesting ones

is the effect of the adaptive response to an infectious agent, like one study looked at the injection of a bacterial endotoxin. And this was like Wimhoff and his followers. They were 14 people, and they saw that the people who did the Wimhoff method and cold exposure,

they had a lower increase of IL-6 in TNF Alpha. so these inflammatory cytokines and responses endotoxin. But, I mean, this isn't been like a study that's been replicated since then. But, I mean, there is still some claim to be made about, you know, the effect of the stress response changing the immune system. Like if you do cold exposure and you have a robust stress response and you increase the neuropinephrine, increasing cortisol,

and these are known to modulate the immune system to kind of prepare it for infectious processes. So maybe there could be some case to be made about the stress response from the cold helping to combat infections, but there's really not any studies about this yet. But I think at this point, it doesn't seem like there's a robust systemic response aside from these edge cases maybe. Yeah, and going back to our sauna study, we found that there was a significant reduction in pneumonia. and you know this was hospital-based pneumonia data they were looking at it was a 37% reduced risk of pneumonia with with the people that were using the sauna four to seven times a week compared to one time a week there was a 78% reduction in psychotic disorder which I think a lot of it probably was delirium

this was all types of psychotic disorders in patients who were excluded to have antipsychotics at the beginning of the study. So, you know, was it the cold? Was it the heat? Was it both? Was it the practice of doing something like that over time, right? Because also it's hard to study in these types of things

like, okay, is it, you know, is the cold water swimming? Is it the exercise? Is it the cold and having that stress? Is it the sauna and having that sort of positive impact? So I would probably say more studies are needed at that point. Yeah, definitely. I think that was going to be like our general conclusions

for a lot of the stuff that we're talking about today. There's just not great quality studies out there. There's a huge need for it. And then one more thing about inflammation that I did want to mention is like obviously people use like ice packs and a lot of people after exercising they'll do ice baths like I mentioned with athletes and it does seem like there could be a potential role for post-exercise inflammation like one study one meta-analysis didn't show an effect but we know that as we'll talk about a little bit later that cold exposure does decrease anabolic signaling

which itself is reliant on inflammatory processes and muscle damage, cell damage. And it dampens that response. So there might be some effect for a reduction in localized inflammation, for like a muscle to reduce the splying to reduce the main response there. But it doesn't seem like there's a systemic response towards cold exposure. Yeah, good point. so when my kid bumps his head, I'm still putting eyes on him. Yeah, I think I would.

Decreases the swelling and the pain. You know, there's, I think with the exercise ones, we'll get to it, but it's like with hypertrophy, people are trying to get a little bit of inflammation in your muscles to get that hypertrophy, to get the muscles to increase in size. I think this is saying you may not get as much hypertrophy, but you will get the strength at aptrophy.

which is interesting, right? That's what we found. That's what we found right. Okay, so what about the psychological aspects of cold therapy, mindfulness, overcoming dissociation, which I would say the dissociation is something that I've thought about.

It's like, you know, I could be in a little bit of a dissociative haze, like I said, and it can snap me out of it. I could wake up in a funk, it'll snap me out of it. That dissociative state, kind of the not quite fully present in your body, we all can have dissociative states.

It's not like you have to have, like, D.I.D. or some trauma to have it. If you are overly saturated with distressing topics, you may yourself feel a little bit more dissociative. I have seen cold exposure help people snap out of a funk. So, in regard to the psychological aspects, what did you want to mention? Yeah, I wanted to mention that it does seem like cold exposure is kind of like a mini meditation or like a mindfulness session because it kind of brings your attention directly to the present moment and to your body. So it increases that bodily connection, your thoughts to the present moment,

your attention to that instead of, you know, whatever goings on you have in your life that's stressing you out. It really forces you into the present and to think about what you're feeling in your body and to have to calm yourself like your your breathing and instead of being like and gasping when you're in the water to slow your breathing calm your breathing like that that is profoundly relaxing and i just wanted to read some of the quotes from a qualitative study that just came out in 2024 about Danish swimmers cold water swimmers they said it can be quite meditative to sit there in the water you quickly forget other things and have a strong focus on being present in the moment because it's challenging to think about other stuff when you're hitting

or getting hit with that cold water constantly so I don't think much is happening in your head. Here's another quote. Sometimes it can be challenging to sit and meditate and not think about anything. But when you get in the cold water, you just can't think about anything else. It's like the body with the cold and the warmth just forces you to be in the moment. And what a antidote to the world we live in, right? Where it's like there's so many things pulling for our attention to be fully in the moment, present.

Right. It's, I think, I think most people should engage in a practice like this that takes their attention away from whatever default setting it was in, thinking about whatever is going on, and then just collapsing them to this setting where it's like they're completely intact to their body. And then after that,

you can, maybe your attention is different. And you think about different things that are more important, like, oh, I have to go exercise or I have to go walk the dog or do something more productive. I think that it gives you an opportunity to do that. But I think it also, you need to put it in context where you can allow yourself to do that. Like you mentioned that you do some cold exposure when you feel like dissociated. So it really allows you to give that event to where you can go from one setting and then to it next, or one state of mind to another state of mind. So I think there is a profound benefit

for that. But unfortunately, there's not many studies that actually address that. You know, there's two things that come to my mind. One is for patients with borderline persia disorder, part of DBT is to grab some ice and hold ice in your hands, maybe like rub it on your forehead. This has worked in a number of patients who dissociate. Now, I had one patient who would hold something cold and it would make her dissociate more because it was so unpleasant. So you have to gauge the person. I remember one. Yeah. I have a, I have a freezer down the hall and I had this patient who was dissociating and went down there and had this cold cap that you put on your head. And I was like, do you feel better? She's like, yeah. And I looked at her and I could

feel more dissociative than she was before. Like I can feel someone's dissociation. I was like, do you feel, it's okay if you feel worse. She's like, yeah, I feel worse. I'm like, okay, let's take it off. And I think she appreciated me not noticing, you know? She was like wanting to appease me by doing this thing. But then when I, I could tell she was doing worse on it, she stopped and she felt better. So we have to be careful as providers as well, as saying things.

And then patients do it just because they want to make us happy. That's a risk. Okay, so the first thing is, Some it helps, some it doesn't, pay attention, experiment with it. The second thing is, once in a while I hear of someone jumping into cold water as like a suicide attempt. And then once they're in the water, they decide they want to live. And I've heard this a number of times. And then it occurred to me as I'm thinking about this.

Like, oh, I wonder if the cold snap them out of whatever funk they were in. and like they you know it changed how they were thinking about hurting themselves in the moment you know so right even like the previous study that we're talking about with brain activity changes like it does change the prefrontal cortex dorsalile prefrontal cortex and you're saying that all these regions that are associated with you know constructing narratives and what's important to pay attention to so i think there is something to be said about hold exposure snapping someone out of a certain thought pattern potentially. Yep. Okay, so the placebo effect, let's talk about this, because is there any data to support that this is just a placebo, right? And we know, we know from

placebo studies. If you go back to, I think it was like years ago, I did an episode with Mark Hart on placebo, we know that like if you inject someone with something, it increases the placebo response. if it's a surgery, it increases the placebo response, right? If the pill is a bright color versus white, it increases the placebo response. If it's an expensive pill versus a cold one, it increases the placebo response. So what did this study find?

Yeah, there's two studies that I wanted to mention. The first is, I think, really interesting. It just came out 2024. It was 21 days of Wimhoff method, which is the cold showers. plus rapid breathing. So they didn't use, like, extreme cold, but they used cold showers,

which itself is kind of stressful. And then the active control was warm showers and slow breathing. So the complete opposite of Wimhawth. And they looked at 78 patients with mild depression, a pHQ score of like around 10 to 20, and these were all women.

And both groups experienced a 20% to 30% reduction in depression and anxiety, but there are no differences between the groups. And how long were they in the cold? I think they were just instructed to go for as long as they could tolerate. And was it a shower or was it an immersion? It was a cold shower.

So in terms of the duration, it looks like they increased throughout the week. They first started with 30 seconds for days 1 to 3, and then 1 to 3 minutes for days 4 to 6, and then 2 to 3 minutes for the remaining days. again for a total of 21 days. And the breathing practice was roughly 15 minutes per session. So that's significant. That's it.

That's a real, that hasn't impacted in of itself, right? Sitting there, breathing, slow breaths. Yeah, it is an intervention. But you wouldn't think at first that this would cause an antidepressant effect or an anti-anxiety effect. but I mean it is a type of intervention so again does that say is this cold Wimhoff breathing is that beneficial or is it just doing an intervention

also people participants were given money they were recruited through local outreach newsletters San Francisco employees flyers online advertisers okay so they were given $470 for completion you know so i'm always like okay are these like let's the incentive are these guys are these people like oh i better score high on this coming in okay what is the temperature of the water i don't think they're ported the water temperature i think it was just as cold as they could get in their shower

yeah i in california what time of the year is it i don't think it was cold enough no it definitely was not, I don't think. I don't, and shower is such a different experience than just immersion. But everyone got better, and so I'm thinking it probably was the breathing and just being a part of a group

doing something, doing something different. I mean, 15 minutes of breathing, I think it's a mindful activity. So I think essentially you were looking at two different arms of mindfulness. I don't think that the cold was cold enough. Which I think, so it's like,

I wouldn't look at this study and say, oh, look, it's a placebo. Cold immersion is a placebo because it just wasn't cold enough. Yeah, that definitely makes sense because you're not going to have the same physiological effects. Like you're going to have some psychological stress going into the shower if it's cold, where you're not going to see that with the warm showers. So that's like pretty much the only difference that you'd see is maybe some psychological stress and then overcoming them, but not to the same extent,

nearly as much as a gold punch. And I don't think, what I could say from this is that I'm not sure that the Wimhoff breathing is magical compared to just slow, mindful,

more like the yoga breathing, which I think is really good. Like that's the kind of biofeedback breathing that people do. You know, that slow breathing, 15 minutes. Interesting.

Okay. Well, you guys can look at that study more, and if you have other thoughts, let me know. But I'm not thinking that that takes away my... It's not like the placebo was... Or the Wimhoff was like five minutes at 45 degrees Fahrenheit, you know, which is kind of like what I would need to see to be convinced that it's just a placebo. Yeah, plus we know, okay, from the other studies, that the norpenephyran changed. when you got to the colder temperatures,

but not that, you know... Not the warmer ones. Not the warmer ones. So it's like you're going to see different physiologic brain effects in those colder ranges. Right. But then again, you can still see like the psychological, but nearly not as much as the actual true cold exposure

where you get some of the bottom-up effects as well. Okay. So let's go to theoretical underprivile. opinions of enhanced mood effects. Oh, I wanted to talk about one other placebo study first. Okay, let's do it. So this was a recovery, like post-exercise recovery study, where I thought the design here is really interesting, and I think they did a better job at controlling for the placebo

effect. So essentially what they did is they used cold water immersion at 10 degrees Celsius, around 40 to 50 degrees Fahrenheit. And they had one group in cold water immersion after a workout. And it had another group at thermoneutral temperature, so around like 70 degrees Fahrenheit. And then another group that had the same thermoneutral temperature, the room temperature water, and then they added a squirt of soap in this water. And they told participants like, oh, this is going to help your recovery. So what they found is that only in the control group without the one that didn't have the placebo, the one that didn't have cold water, only this group had a reduction in a leg strength and higher subjective ratings of pain and reduction in vigor after completing an exercise high-intensity air-vil trading session. Only in what group?

The control group. The group that was in the room. With the squirt of the soap? Without the squirt of soap. So the group with the squirt of soap and the cold water immersion group, both of these groups had reduced pain, increased readiness for exercise, increased vigor after completing a high-intensity interval session.

So they had less soaredess, and they also had greater strength compared to the control group. Okay. Interesting. So I think this is more of a placebo response, like more of a definitive placebo response. try telling every athlete who swears by it, right, that this makes them better. You're right, I mean, like, but it actually might make them better

if they think that it is. That's the wildness of our brains, right? The meaning attribution that we give to things changes the thing itself. Yeah. Yeah, really interesting. I go back to the placebo medications. Like, they did this one placebo study

where they were looking at for Parkinson's patients, how much a placebo increased the dopamine in the brain, and it actually increased it because they told the participants this was going to increase the dopamine in your brain. And the dopamine increase was associated with reduction in Parkinson's symptoms. Yeah. And you also see other mind-body connections with sham surgeries and patients with fake knee surgeries,

and they have reductions in pain, and they never have any complaints. So there is definitely a mind-body connection. You can alter the immune system, maybe change how your body repairs itself or how you perceive the pain signals from your body. So there is definitely a placebo effect. And also think about patients that are given a nocebo effect.

Like when doctors say things like, I'm looking at your x-ray and you're bone-on-bone. is going to hurt the rest of your life. And it's like, no, don't say that. It's never bone on bone. Like, don't say that. It may not, like, it's an awful thing to start believing that you will never get better. That's the worst. Like, you want to, yeah, okay. That's good for getting new replacements, though. It's good for the industry. Okay, let's talk about the theoretical underpinnings for enhanced mood effects. So again, you have a profound increase in noroprenephrine if you actually engage in a cold,

a cold plunge or very cold cryotherapy. And this could have some implications for anxiety. There are some theories about the mono means still being important for anxiety. Maybe for PTSD, there might be elevated noropornevrine. So some of the arguments for cold exposure could be that, It kind of calibrates a signal-to-noise ratio on fear and anxiety. So if someone has too much anxiety when they're not supposed to, due to their neuropronephrine increases when it's not supposed to.

If you give your body a really strong stimulus, like a big stressor, exercise or cold exposure, that increases neuropronepren than these other things that typically cause anxiety in this person, maybe that doesn't cause anxiety because they recalibrated the neuropronephrine system. That's pretty much the theory behind it.

Yeah, and that's, we're seeing the opposite of that with kids that do nothing stressful and they can live years of their life with having no real stress in their life and then the normal stresses of life are overwhelming. Right.

And so perhaps this is a way of doing something stressful progressively that then teaches your stress system to recalibrate. I think that's possible. I think the norpenephyrant, the dopamine increase as well, right? Both of these are for medications to improve focus, depression. You know, we give oputrin, we give atomoxetine. Sometimes these help with, with mood, with focus, and addiction, right? And so, yeah, we give, we have. And so, yeah, maybe that's part of it. Maybe there's other mechanisms we don't know yet, right?

I mean, I feel like when you look at like the field of study for a lot of different things, it's a lot more extensive than this field of study. But I think the claims that are being made, like relative to the amount of evidence, I think it's actually incredible. Like the claims that are being made on podcasts and the anecdotes out there. And there's really not much evidence base to go off of. which I think this is, I think it is really exciting because of all these anecdotes out there, and there is a potential mechanism to explain how can improve your mood.

I would say the one other patient that really sticks out to me that is really benefited is this young 39-year-old female who had depression, real episodes of depression, like discrete, major depression, would get severe. She was on, I think, so long. off 50 and it wasn't doing the full effect this time. And so I said, well, you know, this, you live by a river. Why don't you just jump in the river three to four minutes every day and see if that's helpful? So she comes back one month later. And you know, usually when I give recommendations, I don't expect 100% follow-up, follow through. She, she had 100% commitment to this.

and she was in a place where it was cold enough to get the benefit. And she said it was like a night and day difference. It was like the veil that was keeping her kind of like in a kind of a haze was completely gone. And she was back working, doing business ventures. And this is someone who had done a lot of therapy. she was in medication, she was in therapy, but this seemed to be like very pronounced. And she continued doing it.

And she was able to get off of the antidepressant after like about a year and, you know, swears by it. So I don't know. There's not, there's a couple case studies that I have, right? That's one, this older gentleman is one, my own experience, but I think I agree with you that there just isn't a lot of data. And so I'm very hesitant to be too exuberant.

Right. Because, you know, the last thing we need is to think that this is so much better than therapy or something for, you know, it's like, no. No, I think it could be like as an adjunct, similar to exercise where you have the body benefits. You have the mind benefits too. In my own mind, I would put exercise above this and the hierarchy of like things, because exercises, there's so much data. There's huge meta-analysis. The effect size is very significant.

For mild to moderate depression, it seems fairly equivalent to medication to therapy. I would say therapy probably has a bigger effect size when you're doing a big dose of therapy. When you're doing 50 sessions of therapy, you're getting 75% of people out in remission for moderate depression. Okay.

So, yeah, so maybe it's the normanephyrant. What is it less likely to be the mechanism? Because there's some other sort of ideas about how this might be improving things. What is less likely in your mind? I think it's less likely the cognitions about, you know, how someone perceives the world around them. Like, I mean, to some extent,

you are changing the way that someone thinks through like this acute stressor. Like you're capturing their attention, collapsing it, changing it from one state to another, but I don't think it really changes a lot of the cognitions about oneself potentially or like someone's propensity to misperceive a threat

like in QC and PTSD or more negativity like you see with anxiety and depression. So I think those things need to be targeted through therapy and this is more so just something that can give someone a little bit of a boost to go throughout their day and have a snowball effect potentially, at least in cases of like mild to moderate depression potentially. Yeah, I would say if you have deep rooted childhood attachment-based traumatic events that have left to, that have led to beliefs about yourself, beliefs about others, you know, that's not going to help Right. It's a, it's a lot of therapy, really. It's like transfers, focus therapy, mentalization-based

therapy, you know, these types of therapies where you get into the deep interpersonal, the depth work, reflective function, work on the reflective function, stuff like that. Initially, I was excited about brown fat until you dissuaded me of my excitement. I was like, I was in the cold plunge. I was like thinking to myself, my white fat is turning to brown fat. Brown fat essentially just says more mitochondria. I was visualizing the white fat turning into brown fat. Your A1C going down too. My A1C going down, I was so excited about this, and then you kind of, you popped the balloon of my excitement. Tell me about that.

Yeah, so brown fat is this tissue, like you mentioned, that has more mitochondria in it, and it's typically seen more so in infants because infants don't have the same. like thermogenic effects. They have a larger surface air to volume ratio so they lose heat, so they need more ways to produce heat in their own body. Other small animals also have more brown fat. So if you're looking at a study of mice and seeing like, oh, they have improved insulin sensitivity and mice.

Well, the mouse also has a relatively higher percentage of brown fat. So in the mitochondria of brown fat, there is an uncoupling protein that allows it to uncouple the electron gradient that allows it to generate heat essentially and this is what allows for you know babies and these small animals to to have heat when they otherwise are losing a lot of heat and people who are advocates of cold exposure they claim that because you're activating the brown fat which there are some studies that have shown that brown fat activity does increase during cold exposure, that you're going to be burning more calories because you're uncoupling the mitochondria and you're generating,

you're increasing the uptake of these mitochondria of glucose and other nutrients so that you're burning more calories than you otherwise would from just sitting there. And they think that if you increase your relative amount of brown fat in your body through cold exposure, or then you can just burn more calories throughout the day. And a lot of this actually came from this discussion of brown fat recently. It came from Dr. Soberg's initial study on looking at a group of cold water swimmers. She compared cold water swimmers to controls that had about the same physical activity levels. And they looked at the relative amounts of brown fat and the activation of brown fat

when they were in a cooling condition, they put a cooling blanket on them that circulated cold water on them. And what she found is that there is a 500 calorie difference in daily resting energy expenditure. And so this whole narrative about brown fat allowing you to lose 500 calories,

like 500 calories every single day is a difference of one pound of fat, like 3,500 calories equates to one pound of fat. So this would mean you could be a lot leaner if you activate your brown fat. But the problem, one of the main problems with the study is that this 500-calorie difference, it comes from an extrapolation of when they were doing the cold exposure. So brown fat's only going to be active when you're cold. So it's more active in the winter.

It's more prevalent in the winter. And people who have less body fat because they don't have as much fat to insulate them. So in this study, the cold water swimming group had less body fat overall, and they had more or higher active brown fat during this 10-minute session or 30-minute session of cooling. And what they found is that equated to a 10-calorie difference in resting energy expenditure during that 30 minutes. So when you extrapolate that 10-calorie difference in 30 minutes to 24 hours throughout the days, which is what they did, that's 480-calorie.

or about 500 calories throughout the entire day. And that's not at all the difference in energy expenditure between the groups. You broke my heart, Liam. I was imagining myself burning 500 more calories per day. Right. I mean, it is just kind of absurd, like how much brown fat is actually on the average person.

And in one of these participants in the cold water swimming group, they didn't have brown fat. The swimmer did not have brown fat, so they got rid of the subject. So brown fat is very, like, dependent on the individual. A lot of it's genetic. And even still, it's only 50 to 300 grams, so up to a pound at most on the average person.

And to think that one pound of tissue can burn that much calories is insane, especially when you compare it to the brain, which the brain takes up probably about 20% of your body's total calories, your basal metabolic grade. You compare that to muscle, you can have pounds of muscle that take up so much glucose. That's a huge driver of your metabolism.

And then you think that one pound of tissue, just because it has more mitochondria, it's not going to really change the needle on anything. Yeah, I think this is where I come back to, you know, if you want to be metabolically healthy, the priority is probably strength training. cardio. I can't see that

being a lose situation for someone. Right. Yeah. Yeah, you get the metabolic benefits, the health benefits, mood benefits.

Yeah. The total, I mean, the other thing is like 500 hours a day. If you are cold all day long, like no one is in a cold situation all day long.

Yeah, and I think one of the interesting things, like, even if you assume that you're really maximally uncoupling the mitochondria, the brown fat, say it's working all day, you're not going to lose that much weight. Because there's one fat loss molecule that have been studied since the 20th century is called DNP. And even some supplements have it today and some bodybuilders use it. this uncouples the mitochondria like you'd see in brown fat but uncouples it in all the tissues in the body and so even then this leads to a weight loss of about one pound per week from like a relatively moderate dose so that's assuming you're so comparing that to brown fat um you know you're assuming that the brown fat is that meant by after that it's not the case yeah And I think, like, if you want to think about, like, insulin, glucose health, getting, getting glucose from your meal into your muscles, the best thing is to go for a walk to do a little bit of exercise after every meal or before every meal for about five to ten minutes.

I mean, that has a huge impact. And I would say much better. So me and the kids will go jump on the trampoline for half an hour after, like, dinner. and I feel like that's probably a much bigger win despite me wanting this to be a thing. I know. It sounds like it'd be nice to just sit there for two minutes and kind of rough out or sit out the cold

and then have like a lose a pound a week. That would be awesome, but it's never that easy. Yeah. Okay, so cognitive performance. How is cognitive performance changed by cold exposure? Yeah, this systematic review was pretty surprising to me. They looked at 18 studies comprised of eight studies that looked at the effects of cold air exposure, so not that convincing.

And then also 10 studies that looked at cold water immersion. And they looked at different cognitive performance measures like working memory, executive memory, processing speed. And they saw that in 15 out of 18 experimental studies that, cold exposure within the minutes to hours after actually reduced processing speed and executive function and then working memory and attention seemed to it was dependent on the study but some showed deficits some showed improvements so in effect like and this is kind of my experience too the couple times that i have done cold exposure is that i i did feel a little bit slower

and i did feel like i was losing my train of thought a little bit more and it but I think the main thing from the study is that a lot of these people were naive to cold exposure. So I think over time, you might get some more benefits to it. As your stress response kind of dampens a little bit, you get less cortisol, maybe less noropreneffrine. Because we know the stress response is not supposed to help you increase your executive functioning. So being more stress might actually reduce some markers of cognitive performance like you see in these studies. Yeah, I think it may be person-specific, you know. And also I would say when you look at like atomoxetine,

an orphan-reepid re-uptake inhibitor, these are given for three to four weeks before there's an improvement. So there could also be epigenetic phenomena that hasn't fully been studied. So I would say more research needed. But for someone like myself who says, hey, if I'm in a dissociated state, it really takes me out of it nicely. You know, whereas some of my patients,

maybe it makes it worse. So it's kind of like you have to gauge the person. Right. Yeah. And let's talk about safety precautions, risk of arrhythmias because of that high sympathetic parasympathetic activation. I would say, you know,

even this morning when I got in, I could feel like a couple palpitations, you know so maybe if they are at risk for aphib or they've had a history of arrhythmia be a little bit more cautious yeah any thoughts on that yeah so there's like two mechanisms that people think that cold exposure might cause arrhythmias and that's like you mentioned the concurrent parasympathetic and sympathetic activation and you only get really the parasympathetic if you get the vagus nerve submerged, so that's submerging your neck and your face, and that's called the dive response. And this is often used in patients with superventricular tachycardias.

They're told to put their face in really cold water to try to get the vagus to calm the heart. So the concurrent activation of that might be some effect. And then also the arrhythmia might be due to hypothermia as well. So hypothermia, it can't. can cause arrhythmias, and this is most dangerous with the after drop. And so the after drop is when you're in the cold for so long that the blood in your arms and legs, because they're vasic constricted, it can kind of pool in your arms and legs and become really, really cold. And, you know, your core body temperature will continue to drop after you get out because this blood after you get out, there's less vasic constriction, the blood from your arms and the leg, and

the cold blood can mix with your core blood that has been warm, and that can decrease your core body temperature further, and then lead to hypothermia, and that can lead to arrhythmia as well. So in any patient who has cardiovascular disease, whether that's eschemic heart disease, heart failure, or things like long QT syndrome, they're at high risk for arrhythmias and maybe eschemic events, and then anyone who's in the cold for so long,

they're also at risk for arrhythmias. Interesting. Yeah, I would say that being said, in that Finland cohort, when they followed people for years who were using the sauna and maybe finishing with something cold, these people had lower risk of heart disease, lower risk of stroke, lower risk of all-cause mortality. So you have to know the risks, but also the benefits.

Okay. Right. I think one main difference about cold exposure compared to exercise in sauna too is that an exercise in sauna, it's a gradual ramping up of your sympathetic nervous system. So your heart rate is slowly ramping up. Whereas with cold, it's all of a sudden. Like, it's a shock. So it is a little bit of a different mechanism.

But if you're a healthy person who does not have any... erythmias or any heart disease, then I think it probably is safe. As long as you have someone there with you, they're not going from never having done cold exposure to ice cold water, then maybe I think it's probably safe to do so. But again, consult your doctor. Consult your doctor, yes. This is not medical advice. This is medical, this is information for informational purposes only.

Exactly. I actually will not go underwater with my head for more than like 10 seconds if I'm alone. Some people may, but I personally, that's where I'm like, I'm going to wait to do this with a friend. Right. Okay. So recommendations in future direction. What I was thinking about is imagine someone listening to this and they're like, you know, I want to do a randomized control trial. Feel free to reach out to me or Liam so we can consult with you so we can talk about it.

I think it's a great idea. I think someone young who's listening that should consider doing it. We were even talking about like, man, I would do it. GoFund me for that. Like, I want to see a really nice randomized control trial on this.

Like multi-site. Let's go. Liam was even thinking about doing it for a second. I mean, yeah, if I could get funding, I think that's probably the hardest part. But I know there are a lot of podcasters who do philanthropic work

for like mental health treatments. So I think this could be, if someone is really interested in that, they could try to search out through those avenues. Because this is really something that the benefit to harm ratio is, I think, really positive. Like, it could be a really good benefit at a low cost, a low harm to someone. So I think it's something that a lot of people could use on a regular basis. Yeah. I think for future randomized controlled trials, my thought would be somewhere on first, 45 degrees Fahrenheit, three to five minutes, maybe start it to build it up.

And then have a control group, which is probably more like 75 degrees. So it still feels maybe cold. And you have to control for any group exposure. So if you have a group doing it together, you have to have two groups doing it both the same time. You can't just have a weightless control. So you have that group event controlled for. I think I would do the cold plunge rather than cold swimming because it would be to control for the exercise aspect,

unless you would have them swim in a normal pool, which I think is also possible. So if you're doing some cold water swimming to have like two different environments, one being a normal pool for swimming, one being a cold pool type of thing. So those are some of my thoughts right off the bat. And then I also wanna, I would wanna do it for like,

six to eight weeks, you know, maybe then you get to see the kind of the epigenetic phenomenon that would happen. Right, you see how they change in response to the cold by habituating to it. Because like I said, the cognitive effects, they might go away after a while, like the decreases in working memory performance and everything. I'd also do more moderate depression rather than just mild. I'd want people on, you know, not just like a very low level of depression or moderate severe.

Yeah, I think it would be cool to also measure like norprodeferin, dopamine, the monomone, cortisol, and then also measures of like self-efficacy and seeing if that has any moderating effects on the treatment response. Like if someone believes that the practice is beneficial for them or, you know, if it helps them get through their day, then maybe that can explain some of the antidepressive effects of it. Yep. I go back to the study that they did where there was a drop in that Beck Depression inventory

that was significant, even in the first week, kind of plateaued out with the other group, but that first drop was, wow, that's very interesting. So maybe as an adjunct for overall treatment just to get someone started on depression. But this is so early, and we only have one study. it's like before I recommend everyone to do something on this podcast,

I try to make sure it's like really studied out. Otherwise, you know, it's like premature, premature overexitement. It's not what I'm about. Exactly. I mean, as clinicians, we have to like really make sure that what we're recommending has gone through the rounds and research and shown some benefit before we can actually claim it. because a lot of the podcasters, like, they don't have that responsibility to the patients.

They can pretty much just say whatever they want, as long as it garners attention and some traction, then they're going to have some benefit to themselves. So, yeah, as clinicians, we have a higher responsibility for our patients. Yeah. There was a lot of people that recently came out with this statistic that exercises one and a half times better than therapy and medication. And it's like, no, that's not what the study said. It is very catchy. You know, are we looking at severe depression?

No. Are we looking at, you know, the same level of control groups? No. So, yeah, it's, we have to be careful because then, you know, the public starts to get kind of like, oh, don't go to therapy, go coal plunge. Like, that would be a nightmare. If that's your takeaway from this, like, oh my gosh, like, please. please go to therapy, please do the hard work.

If you have severe depression, you may need medication and therapy, and you may need a bunch of other things as well, like exercise and getting rid of processed foods. That's helpful. And maybe try this, sure. But it's like, I don't think there's only one type of treatment that's going to supersede things that we know work

and know we know work really well. so all right sir thank you for coming on leam browning this is amazing we appreciate you uh the handout is on psychiatrypodcast.com you can get cme continue medical education for this and uh i'm excited to have you on in the future maybe we'll do an episode on dating and the difficulties of dating in this modern time people what would you like leum to dive into next please let me know and yeah I'm open for anything. Yeah. Thanks for having me back on.

And again, if someone has any ideas on how we can initiate a trial for cold immersion, I think that would be awesome to get connected and, you know, see if we can get something going. Awesome. All right. We'll go from there. Thanks.