Can working up a sweat in a sauna improve your health?

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Hello there and welcome to the Inside Health Podcast. I'm James Gallagher. I hope you're all well. In a bit, we're going to go behind the scenes of the first treatment for the devastating disease Huntington's and find out what it means for families.

But first, we're seeing what saunas do to the human body. They're popping up all over the country with claims that high temperatures boost your health and well-being. But are they all they're cracked up to be? I went to Morasona, overlooking the beach in Jackson's Bay in Barry Island, to find out. That's not correct. Hello everyone. Hello. Who loves a sauna? Tell me why. Oh it's

so relaxing it just makes you feel at ease. It's also great for um relaxing muscles and if you're up tense or anything like that at all. Yeah I always love coming down here when I'm a bit stressed out um and by the time that I'm finished I feel like I've completely reset. It's wonderful. Well I'm here as well with Professor Damien Bailey, who is the first time.

Borderline our resident physiologist these days. You're on so much Damien. You're gonna help us actually explore the science of going in a sauna and what it actually does to the human body.

What are we gonna do? So we're going to instrument you with lots of different wearables Um so we'll have blood pressure, we'll have heart rate, we're gonna measure how many times you breathe, uh skin temperature, uh we'll measure your core temperature, and I think that's probably enough to keep keep us busy at least. Well just so we're clear, I'm cold already because it's a wintry day.

It's in Wales. Eight degrees at the moment, so uh eighty degrees centigrade in there, right? Ten times as warm. So do we need to get some measurements now before I go in so you have an idea of what my body's Yep, we're gonna like at the moment. We're gonna do some baseline measurements and uh we'll get you rigged up and we'll get you going.

So Damon, all measurements done? All measurements done. Excellent. And Kate's gonna join us in there as well and Kate you've been measured up as well. Yep, all measured up. Can't wait. And how long are we going in for? So we were thinking, you and I, twenty minutes. But Kate is an experienced sauna goer and she's gonna be in there for ten minutes. So my suggestion is we stay for ten minutes. Yeah, I'd say ten minutes tops to be honest. My toes are absolutely frozen. Let's go.

Okay, lead the way code. Oh my goodness. That's a wall of heat already. That's beautiful. Okay, at the moment this is lovely. Oh that's beautiful. Right, let's lay out our towels. Thank you. What temperature is it now? Okay. That says ninety. I'm just gonna state the absolute obvious Ninety degrees. Like water boils at a hundred. Exactly. Yeah. Exactly. Yeah. Like this i this is hot. This is a dry heat though, isn't it? That's why when you suggested going in for twenty minutes, I was like hmm.

Not a good plan. Not a good plan. That's typical overestimating our abilities there, James. Men eh? I think we've been in here about five minutes. How is everyone feeling? I I I'm starting to sweat, I can feel it on my knees. Yeah, I can feel it in my cheeks actually. Uh yeah. You're definitely going red. Yeah. Matching my swimsuit. So interesting there James that we've got a full ten beats per minute increase in heart rate there.

Uh a full ten beats per minute for you as well? Well fifteen beats for you actually, roughly. So that's a normal physiological response again. So I I've gone up from low sixties to mid seventies on my heart rate. Kate. From eighties to one oh three beats per minute. So you've gone up twenty three beats per minute approximately. So a lot more, is it? A lot more. Okay, we're just getting a blood pressure measurement on you, James. I just have a sense that we're not gonna last that much longer.

Do you reckon we should open this door and let some of this heat out? I think we have done enough. Cool. Right then, Damien Kate, shall we get out of here? Yes. Yes please, James. Right, so we've come out of the main bit of the sauna to the little porchy area. Damien, before we get dressed What are the headline findings? So I'm I'm just trying to look at the results because we've sweated all over the data sheet. So um uh there's a mental image for you. I I think I can read it.

So the responses I would say from a cardiovascular perspective heart rate has gone up. Uh blood pressure has gone down, uh temperatures have gone up. What I would say is that Kate, your blood pressure has actually dropped. more markedly compared to James's and your skin temperatures have increased

more than James's as well. And you're breathing less in the heat compared to James. So it's almost as if you're performing better more efficiently in the heat compared to James. You have had more practice. Yeah, I guess we could say that. Well, let's get into what all the science says'cause there have been real proper studies into all of this in a minute, but I think we should Stop having this conversation in our brief.

Well I was so relaxed after that sauna even while wired up to all of Damien's devices, but now that everyone's dressed, let's see what that sauna heat did to my body.

So the first thing the body's gonna do is we're gonna sense the heat and you get this rush of blood flow to the periphery. So we vasodilate and there's lots of different molecules and chemicals that allow us to do that. And that's So that's when all the blood vessels near the skin open up to bring that blood flow to the

And that's where the radiance then comes in. You can see your cheeks are really red, your fingers are really red, and the blood is shifting to the periphery. You're just trying to cool down, right? And we could tell that my body was working harder, as was Kate, as was yours, by what happened to our heart rate.

That's right. So both of your heart rates increased and that's quite normal. So we're shifting blood to the periphery. There's more cardiovascular work, uh more work for the brain as well of course. and you're sweating, you know. We could see that, you know, you and I were sweating a lot. Interesting thing though was that we sweated before Kate. We sweat faster and we fa sweat more than females, um which is interesting and Part of the reason

Why females actually perceive heat better than us? They call out the hot temperatures sooner than we do, perhaps is because they don't sweat as much as us. So we're cooling down, if you like, you know, really rapidly. Whereas with Kate she was shifting blood to the periphery and her finger temperature was a lot hotter than ours. When we start to connect this to the arguments around health benefits.

Skip to the end. Is there a health benefit to going in a sauna? Yeah. I mean I looked at the research really closely. I was fascinated by the evidence. Huge benefits. I mean, really huge benefits. So what does going to sauna do for you and how often do you have to go? Like did my ten minute session give me other lasting health benefits? Yeah, so a single sauna session will give you benefits, but the evidence is based mainly on finished studies.

four to seven times a week, so they're regular sauna goers. We're talking about sauna is part of your daily life. Yeah, exactly. And it's cultural of course. Five million people in Finland, ninety percent of them use saunas. Maybe we should be copying what the Finns do, because there's a forty percent reduction. in all cause mortality with the sauna goas. Now this is what we would call observational data.

But it's based on thousands and thousands of sauna goas. You know, the Finns have really looked closely at their data. So there's definitely something in it. And about a fifty percent reduction in cardiovascular risk. Uh things like heart attack and stroke. Absolutely. You know, generally speaking, sixty five percent reduction in neurodegenerative disease, susceptibility to dementia. So there is

Definitely something magic about the sauna. Do we know for certain, particularly when the data's coming from a country like Finland where it is the something the overwhelming majority of people do, that there might just be something about that ten percent that don't go to a sauna? that is actually the thing that's the difference. Maybe they are those the people at high risk of.

dementia or a heart attack or or something like that. Yeah, it's a great point. And that stops them go going. Yeah, it's a great point, James. And and you know, again, if I was looking at the data real scientists should. These are observational data sets. So we really do need what we call RCTs, randomized controlled trials. So everything, just as you've mentioned there, everything is absolutely controlled. But we can't turn our noses up.

at the current data, the observational data. And from a physiological perspective, we've got every reason why. I mean we're sitting there sweating away and it's a little bit like exercise from a vascular perspective. But we're not building muscle mass in there, we're not building endurance in there. It's like exercise, it's not exercise. It's not exercise and I think we it's really important again that the drum that I constantly beat is

be fit, exercise. What's the evidence around that whole ice plunge after we had a cold shower, but it is a thing, you know, the the team here, the lot here they'll jump in the sea, but like you'll have seen pop up saunas up and down the country where they'll have an ice bath next to a sauna. Like that it does that extra temperature difference.

Yeah, dual therapy, so it's becoming increasingly popular, as you mentioned, and there are some very small studies, not terribly well controlled, the evidence isn't overwhelming, but there's uh a few snippets of information to suggest that there are euphoric benefits. You feel so much better. And maybe it's that differential between the really hot

and the really cold. So it reminds me of high intensity interval training, which we know has got much greater benefits than just ordinary moderate intensity training. I think it's that high blood flow, the low blood flow, which is key in terms of our ability to adapt, the vascular benefits. Again we need RCTs, randomized controlled trials to really investigate that. But uh there's certainly something in it. So Damien who shouldn't

Go in a sauna because it does challenge the body. I would say people with high blood pressure, uncontrolled high blood pressure, so hypertension, uh, with angina, so chest pains, and people on certain types of medication that they need best advice to have the conversation with their GP. And of course somebody who shouldn't go in the sauna really are pregnant women, certainly during the first trimester. Uh again And how should you do it safely? Are there any top tier? So I would say five minutes.

at about eighty degrees centigrade, just start off very very slowly and drink Plenty of fluids. Make sure that uh if you're feeling a little bit dizzy, if you're feeling too hot, we were scoring ourselves. I was extremely hot and I probably could have left the sauna a good five minutes. sooner. So it's not a test, it's not a feat of endurance.

And alcohol in a sauna is a bad idea, right? Absolutely good point. I forgot that one. That is absolutely key. I mean you do not want to be dehydrating, you do not want to be cognitively impaired when you're going to the sauna. Um and if you're just feeling really uncomfortable, call it early. Uh an Ur on the side of court.

I am I suppose I'm a bit surprised that you are so convinced by the evidence. A and you were very careful going through the caveats of kind of like this is what we call observational data, but you look like a man converted. Yeah, I've gotta say I I always defer to the evidence. I mean that's what we do as scientists, right? It's it's you know um work that's published in high impact factor reputable biomedical journals. And I did come into this as a bit of a skeptic.

But the evidence to date to me suggests this is something that we should be trying out. I can tell you now, after having looked at the literature, I am definitely gonna get us all out. Damien, thank you so much. My pleasure. Good to see you. Come around and have a swat with me, Jake. Th there's an invitation no one can refuse. You're listening to Inside Health, I'm James Gallagher.

We're going to spend the rest of today's episode talking about Huntingtons. In September, I reported on the first ever treatment for the disease with data showing that Huntington's was slowed by 75%. Now this disease is cruel and devastating. It runs through families, relentlessly kills brain cells, and it resembles a combination of dementia, Parkinson's, and motor neuron disease.

Now this treatment was an experimental gene therapy delivered into the brain during hours of delicate surgery. The therapy reduces the production of the toxic protein that's behind Huntington's. The announcement of the results of the trial was probably the biggest health story of last year, and for the first time I want you to meet the people on the trial and the team that delivered the therapy.

Uh hi James, welcome to Cardiff. Uh we're here in the uh MRI scanning suite in Cardiff University Hospital. Um I'm Liam Gray, I'm the professor of neurosurgery here. Liam, thank you so much for inviting us in because this is the place that that pioneering Huntington disease therapy took place, isn't it? Yeah absolutely. We we did all the UK surgeries and we're

One of the few places in the world, there's only two in Europe and uh maybe four or five worldwide, that are doing deceptive surgery at the moment, yes. I'm gonna go through the detail in a minute, but can I fast forward to the end? What was your Reaction, how did you feel when you realised that this was working and actually was the first time in Huntington's disease that you were changing the course of that?

devastating condition. Oh it it was um yeah, it was an emotional reaction to be honest. Um, you know, we've been trying for fifty years to try and find a cure for this disease. There have been many, many, many attempts and suddenly Th the needle has moved um and this study has shown that it is possible.

to slow the progression of this disease which I think is absolutely amazing and very very emotional for everybody involved. This is a substantial and delicate piece of surgery in order to do it. Just walk me through the process because what it's it's well over ten hours of

Surgical time, isn't it? Yeah, I mean the for for this study and these types of studies I think the average was about fourteen hours for this for this surgery. So so this surgery is quite different to what we normally do.

in that uh we normally operate in a in a standard neurosurgical theater but all the surgery is done in an MRI scanner. Just paint the scene for me of what it's like doing that surgery inside an MRI machine because I I picture that as like a Like you're going through like a thin tube. Uh no the the uh the the participant is going through a tin tube a thin tube. If you look at an MRI scanner, when people get into a scanner you lie on the table and you go in.

Actually there's an other end on that you can get out through as well. and the patient's head comes out through there and we do all the surgery at the back of the scanner. And then does the patient go back in and out in order to know that you're in the right place at the right head. Exactly. And the the patient gets

scanned uh continuously during the whole procedure. Why are they happening to be in an MRI machine?'Cause like I I I've witnessed other brain surgeries and and what often happens is you have the MRI scan beforehand and then that's enough, that's enough to operate on.

Is we need to be able to see the infusion in real time. The catheters that go in to deliver the therapy uh they're they're movable, so we need to advance them and we can adjust the flow rate. You need to get some feedback, watch how it's going. Um these therapies can reflux back up the catheter.

They can leak into areas you don't want them to leak into and you need to be able to see this in real time. And how precise do you have to be? Does the h therapy have to get to one very particular part of the brain or is it enough to just kind of get it in the No no it's it's it's not a general spray paint job. You have to get it exactly where you want to get it. Yeah so these target structures are quite small. They're a few cubic centimeters in size.

And we have to fill them maximally as well. So it's not just getting it in there. We need to be able to fill as much of the structure uh a as possible. And Leem, is that the MRA machine we can hear beeping away in the background? The very one, yes. This is our one of our three Tesla machines here, and that's the one we do all the surgery in.

What is the bit of the operation that takes so long? Is it because you have to be very delicate with putting the infusion into the brain or or is it the lining everything up? Well, I I I I think both, to be honest. I mean the infusions are slow because if you infuse too quickly you'll cause damage. But the major part of the surgery is making sure that the catheters are getting to the right place. and and to do that we have to make lots of measurements and lots of adjustments. And this

Therapy. It's kind of like a combination of gene therapy and gene silencing technologies, isn't it? Because you're trying to shut down the production of the toxic protein that kills brain cells in Huntington's disease. Yeah so in Huntington's disease uh there's a protein called Huntington um uh and these patients uh have an adamantity in the gene so that makes the protein misfold.

and then it it appears to have some toxic characteristics. So this therapy is knocking down the production of this uh either total protein or the mutant part of the protein depending on the therapeutic that's used. And this was a huge amount of work for you, but it's also a really big thing for anybody that was volunteering to take part in this research, not knowing that it would be the first to show that it worked.

Both I and the team have huge admiration for these people. These are courageous people who are taking risk up front to have a therapy that might do them harm. It might have no benefit whatsoever. Um they are undergoing brain surgery and they have no idea whether there's going to be any benefit. When I operate normally for

the other types of neurosurgery that I do, there's always a benefit. There is a risk, but there's always a benefit. In this situation, we don't know there's any benefit. And these people are really doing experimental medicine are and are hugely courageous to do so.

Well now I want you to meet Gareth, who's one of those who volunteered to take part in the trial. He has Huntington's disease and it runs through his family.

HD, different levels, different uh symptoms. Now uh further on uh my aunt developed it just describe what it is like and what Mae'r llawer o'r llawer o'r llawer o'r llawer o'r llawer o'r llawer o'r llawer o'r llawer o'r llawer o'r llawer o'r llawer o'r llawer o'r llawer o'r llawer o'r some uh memory cognitive issues, it's uh it it gets progressively worse. there are potential anger issues. But there's an ambiguity to H D and it's um uh it's inevitable. However, it's extremely unpredictable.

different rate of progression. And Gareth, I I appreciate this is a personal question, but did you choose not to have children because of Huntington's disease? I would probably say yes in that I made a conscious decision not to want to pass the gene on. What made you decide to volunteer to take part in the trial? Because like at the very beginning, no y like it's it's experimental medicine, nobody knows like what's going to happen. Yeah. Uh um now I'm someone who doesn't even like a blood test.

So uh this uh caught a few people by surprise when I said I was doing this and I've shown them the photographs since. Um really I don't like a blood test either. But I'll do fourteen hours of surgery, that's fine. Yes, but Innovative. and hopeful of uh something uh that was to be bright at the end of it.

Just walk me through the day itself then Gareth, what happened? Well uh one of the nurses woke me up quite early. Um I uh was delivered my kind of uh gown etc. which really there was no turning back. So I went to uh got myself changed, quick chat myself in the mirror. Byddwn wedi'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'i'

uh the intensive care unit for a few hours. I think I was out about out of the bed within twenty four hours. Uh I was out of the hospital within the week. And how are you today, Gareth? Feeling pretty well. Um Now I I'm not gonna say that's anything to do with the trial process. I I would hope it is, but y yeah, yeah, I mean it wouldn't be foolish enough to say that. Jane Davis, the lead nurse of advanced neurotherapies at the University Hospital of Wales,

has been side by side with Gareth throughout the trial. I'm in a privileged position where I get to know the Huntington's disease patients and families from a very early stage from when they just just diagnosed and then we see them on a yearly basis over many years and you know you see the different challenges that they face throughout the course.

um, you know, progression of the illness and family dynamics, etcetera So when there is that little glimmer of hope they really, you know, understandably want to grab it. Is it quite emotional? Absolutely, yes. Yeah. Yn ymwneud â'r cymdeithasol ymwneud â'r cymdeithasol gyda'r cymdeithasol gyda'r cymdeithasol gyda'r cymdeithasol gyda'r cymdeithasol gyda'r cymdeithasol gyda'r cymdeithasol gyda'r cymdeithasol.

um, you know, with sort of huge emotional, psychological weight making a decision to take part in one of these trials. Rydw i wedi bod yn gyflwyno gyda Gareth yn y cyflwyno'r cymdeithasol. Rydw i wedi bod yn gyflwyno gyda'i gyda'i gyflwyno. Rydw i wedi bod yn gyflwyno gyda'i gyflwyno gyda'i gyflwyno. Rydw i wedi bod yn gyflwyno gyda'i gyflwyno gyda'i gyflwyno.

approach him about the trial and say, Look, I think you are, you know, yw'n ymwneud â hynny'n ymwneud â hynny'n ymwneud â hynny'n ymwneud â hynny'n ymwneud â hynny'n ymwneud â hynny'n ymwneud â hynny'n ymwneud â hynny'n ymwneud â hynny'n ymwneud â hynny'n ymwneud â hynny'n ymwneud â hynny

neurosurgery, you know, and they wake up and they they know you straight away. It's obviously a huge sense of relief and and just so pleased for him, really. And I asked Jane how she felt when the results were announced. I felt really um obviously really encouraged, but um for me being involved in the research there's still a dose of realism with regards to that. After that day, for me, my workload increased considerably because so many patients were getting in touch. I want to take part.

yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw'n yw But, you know, there is hope and you can't you know, this is the the very positive thing to come out of it.

The headline results of the trial were impressive. A seventy five percent reduction in the pace of the disease means the decline you would normally see after one year would take four years after treatment. Here's Surgeon Professor Liam Gray again. It's a really meaningful difference, absolutely. If we can if we can intervene early and slow down the progression of this disease to that degree.

Um I mean we do have to be aware that we need to know how long this effect will last for as well. So obviously it's early days yet and we don't know but we've no reason to believe why it won't. And how do you know that it was a seventy-five percent reduction in the progression of the disease? Well we w in in this trial we compared the progression of the disease in the participants who had the therapy

to a very, very tightly matched population who are matched for the severity of the disease, et cetera. And therefore by looking at them over time, we can see that the patients who had the therapy the therapy appeared to slow the progression of the disease by seventy-five percent.

Liam, when I reported on this last year there was a lot of excitement that this might come to people quite quickly and be available as a treatment. There was a lot of talk about getting approval in the United States within months. That hasn't happened and doesn't look likely to happen soon now? Yeah, I mean I I think each country is different and I think what happens in the US is not necessarily applicable to what happens in the UK. Uh but uh

Each country has its own regulatory authority and that will license this therapy once they think it's safe and it's effective. Um so that's a process that is taking place and will continue to take place. It's a really hard time though, isn't it, for families who may have seen a parent or grandparent die from Huntington's disease, maybe in the earliest stages of it, think that they have passed the gene on to their children.

to know that there is something that actually the science suggests would make a massive difference and it's not available. It obviously isn't easy if you have the condition and if your if your family have or may have the condition, uh but it really is in everybody's best interest that we know that it's safe and that it's effective.

There have been some questions about how useful this therapy will be because of the amount of surgery that it that is involved and the highly specialized centres like this is the only place in the UK you could do this right, Liam. So Like is this a therapy for everybody with Huntington's disease?

It it may not be a therapy for absolutely everybody, uh but it is a therapy that can be scaled up. So you must realize that we're now at very early stages where we're trying to prove as best we can that this therapy is effective. Once we know that. um then we can work on making the whole procedure shorter, faster, more effective. And really what we're looking at is moving this towards really a day case surgery where somebody will come in either the evening before or the morning of

have the surgery, have the therapy delivered and be able to go home in the evening. So it is scalable. It's just right now we're we're very, very early in the genesis of the whole evidence to show that it works. Liam Grey there. Now I asked Gareth what his hopes for the future were. Rydyn ni'n mynd i'r Celsiaid yn mynd i'r Premier, mae'r Celsiaid yn mynd i'r Celsiaid yn mynd i'r Celsiaid yn mynd i'r Celsiaid yn mynd i'r Celsiaid yn mynd i'r Celsiaid.

Thank you to Gareth, Liam, Jane, and to all of you for listening to the Inside Health podcast with me, James Gallagher. The producers were Alice Lipscombe Southwell and Jerry Holt with researcher Tom Hunt. Technical Production was by Sue Mayo. The show was made by the BBC's Audio Science Unit in collaboration with the Open University, and the Open University's Myth Busting Quiz is back with brand new questions.

To test your health knowledge, visit bbc.co.uk slash insidehealth and follow the links to the Open University. Taxes was feeling unwelcome. Now taxes is an open Literally. Hi, welcome in. They're powered by SmartTech. Get real-time updates while you go about your day. Confident your taxes are This is taxes. Topotech stores opening. Yeah, yeah.

Love finding the best recipes? I'm Samuel Goldsmith, food writer, cook, and host of the Good Food Podcast. Every week I sit down with top chefs, food writers, And people at the forefront of changing the way we All the people who really make food great. If you love a good meal and a great conversation, The Good Food Podcast on Spotify. Serving up fresh episodes every Tuesday. See you there.