You've either seen it, or you've tried it. Ice baths are all the rage right now, in part because they claim to be an effective health and wellbeing booster.
Is this just a fad, or is there solid evidence that dipping into freezing cold water can improve your immune system, calm down inflammation and better your mood?
Norman went for the plunge – and lived to tell Tegan the tale.
Got a health question? Shoot us a line @ABCHealth on Instagram, or send a voice memo to thatrash@abc.net.au. We'd love to hear from you!
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Norman Swan: So Tegan, one of the techniques that's used in podcasting is called the cold open, which is what we do.
Tegan Taylor: Yeah, that's a little bit of industry lingo for you. This is the bit of talk that you hear before the theme sound plays.
Norman Swan: And this is a cold open for a cold show.
Tegan Taylor: Oh my gosh, the dad jokes are never-ending. Yes, we're talking about temperature things today, cold things and a little bit of self-experimentation that you actually did not that long ago.
Norman Swan: Yep, this What's That Rash? (which answers your questions) is about ice baths.
Tegan Taylor: Today's question is from Sue, who says there's a lot of talk and speculation about ice baths being great for physical and mental health. And Sue asks, is there any scientific or medical evidence to support this? And if so, how does it work? And I know that you know about this because I know that you took the plunge, as it were, early last year, and took an ice bath.…
Norman Swan: I did…
Tegan Taylor: For science.
Norman Swan: And broadcasting…
Tegan Taylor: Mostly for broadcasting.
Norman Swan: I did it for 7.30 and the Health Report. One of the people who's well known for ice baths and promoting this is Wim Hof.
Tegan Taylor: Wim Hof is a fantastic name. If you don't know who Wim Hof is, we will explain in detail very shortly. But he's a guy from Scandinavia who has very much popularised this idea of ice baths and kind of using your mind to control the fact that being submerged in ice is awful. But Norman, I don't want to hear about Wim Hof first, I want to hear about what it was like for you.
Norman Swan: Well, I thought it was going to be something that I could make a bit of fun about, and blah, blah, blah, but in fact it was a really interesting experience. The woman running the program, which was on a beach, was really sensible, very pleasant, and she followed the Wim Hof technique. The Wim Hof technique is that you do breathing exercises, you learn to control your breathing, because when you go into an ice bath the tendency is to do very deep breathing and your body gets quite shocked, and a little bit of meditation before you actually do the ice bath. And then she was very strict, you're only allowed in the ice bath for two minutes before you get out and run into the sea to warm up.
Anyway, I thought that I'd be surrounded by people who had these weird and wonderful ideas about ice baths transforming their bodies, but most of the people, who were probably in their 20s, were actually doing it a bit like a bungee jump, it was a challenge you got quite scared about. I was certainly terrified. And with the payoff being you felt good having done it. So anyway, we did all that, and I went into the ice bath, and it's probably the most unpleasant two minutes of my life.
Tegan Taylor: So, this is first thing in the morning, and you've rocked up on the beach, you know what's happening, but how prepared were you for lowering your body into that esky, effectively?
Norman Swan: The woman running it prepared everybody really well. She talked through it, she did these relaxation exercises so you were focused on it, but there was no question, your anxiety level…and everybody's anxiety level was high before going into the ice bath. And I'd done a bit of work on this beforehand, and we'd done some filming in Western Australia with experts in this area. So a lot of the research in this has been military research; what happens when a fighter pilot ditches into the ocean, or a sailor has to go into the ocean, what happens, how long do they survive, and what happens to their bodies?
Also associated with epidemiological evidence is that if you look at men who have heart attacks and cardiac arrests during exercise, cold water swimming dominates the story. So it's not a common event, but if you take the event—cardiac arrest in sport—swimming in cold water is a common cause of that, so that adds to the anxiety. And what happens is…and I felt it would describe my own experience, is that two conflicting things happen when you go into…and research in WA and elsewhere has shown that two things happen. One is your pulse goes down, so your so-called parasympathetic nervous system (this is the nervous system that slows everything down), it goes into action, a bit like a diving reflex in seals and in deep sea divers, where everything slows down to improve survival. But at the same time your anxiety and stress levels go up, so your adrenaline is fighting against…so your sympathetic nervous system drives against your parasympathetic nervous system, so you get this conflict. And some people believe the risk of cardiac arrest is because of this conflict where one part of your body wants to speed up your heart and the other part wants to slow down. And I certainly felt that towards the end of the two minutes, and was pretty glad to be getting out of it.
Tegan Taylor: Did you feel like your heart was racing?
Norman Swan: I felt that the heart wanted to race, but it was an unpleasant feeling in my chest, that it couldn't do that.
Tegan Taylor: That's so weird.
Norman Swan: It was weird and a bit scary.
Tegan Taylor: So did you go numb?
Norman Swan: Well, I suppose…did I go numb? No, unfortunately I didn't, I just felt the pain.
Tegan Taylor: It does hurt. I remember having dares with friends back in the day where you'd have to stick your hand in the esky or in a bucket of water and see whoever lasted the longest. Yeah, it hurts, it hurts so much.
Norman Swan: I mean, I went into it and, you know, there's a camera on me, so I'm saying, 'Well, this isn't too bad.' And there was this young English guy next to me who said, 'You've got to be f-ing joking.'
Tegan Taylor: I mean, he rolled up for it. So, okay, it was painful, it was stressful. You felt like you were maybe at risk of a heart attack. Why did you do it?
Norman Swan: Well, I did it for the nation. I suppose 7.30 was quite happy for me to do it because they could film my death on camera. But no, it felt great when I got out. So having done it, I felt great. And just like everybody else, you felt really good. Psychologically, you'd met a challenge and you got through it.
Tegan Taylor: All right, so I want to talk about the science, and you've hinted at some of it there, but I think…I mean, humans have been going into cold water since we've been humans outside of the equatorial zone, right? Like it's in our habitat, and people have been dealing with uncomfortable sensations through breath work and meditation for a long time, but it feels like it's having a huge moment right now because of this guy Wim Hof, who I accused of being Scandinavian before, he's actually Dutch, I don't know if that counts as Scandinavian…
Norman Swan: On the border.
Tegan Taylor: So his whole thing is he calls himself The Iceman, as if Wim Hof isn't already one of the coolest names on Earth, and he's all about pushing his body to the extremes of what it can do, especially when it comes to doing things in cold water. I looked at his YouTube channel and he does that thing where he's on a frozen lake and dives down…
Norman Swan: He goes running in his bare feet in the Arctic Circle.
Tegan Taylor: Yeah, but you know when they cut a hole in the lake, and then he jumps into it, and then he swims under the ice, which makes my stomach turn, and then comes up through another hole. I can't even think about…the claustrophobia plus the icy cold just makes my stomach turn.
Norman Swan: Part of this is that you do get used to it, and there is a sense that you can train yourself a bit. But one of the things you're training yourself about, which is what the deep breathing is about, is the reflex when you get into it is to want to take a really deep breath, and if you're immersing your body, taking a really deep breath is not a good idea. And the other thing that we were recommended not to do is not to immerse your head, to keep your head above water, because there's some theory maybe to do with the vagus nerve going through your neck and so on, and your blood pressure sensors are in your neck, it could be that immersing your head in this is not a good idea, but what he's learned to do is control this sudden gasp that you get by going into the water. But the breathing exercises help with that as well. So, in some sense you get used to it. One of our colleagues here at the ABC will reasonably regularly go swimming in water that's two degrees when he's in the northern hemisphere. You can do that in the Arctic Circle elsewhere. The water that's in these ice buckets that are human-sized ice buckets is probably about 10 degrees. So the really, really cold water that Wim Hof is diving in is significantly lower.
Tegan Taylor: So, it's called the Wim Hof Method, and there's been scientific studies done on it, which we'll get into in a minute, but there's sort of three things to it. One is the cold, like the actual coldness. One is the breathing, like you said. And then one is the meditation side of it. And combined together, he and others claim all sorts of different health benefits from this. What kind of health benefits are they saying that you'll get from doing this?
Norman Swan: They talk about resistance to infection, improved immunity. They do talk about improved psychological well-being, which could be just from the challenge, reduced inflammation. And when you look at the evidence, such as it is, the best evidence is from reduced inflammation.
Tegan Taylor: And inflammation can kind of be the starting point for a whole lot of different diseases.
Norman Swan: Yes. So the question is whether your blood going cold reduces this inflammatory response in your blood, or it just reduces inflammation externally. So if you've got arthritis and you go into an ice bath, it will settle down the inflammation for a while in that arthritis, just by the cold effect. Whether it does that systematically is another matter, but there is a little bit of evidence that it does.
Tegan Taylor: I am curious to know how Wim Hof got to own this space when at least the breathing and the meditation side of things are really ancient human practices, you see it through yoga and Buddhism sort of thing. So let's talk about what the studies have looked at, because if you're combining all three of these things, you're sort of confounding your own study.
Norman Swan: You are. There's not a lot of evidence, at least from the research we've done for this particular show on breathing. Meditation, which we might get onto in another program…and in a sense an ancillary effect of yoga, apart from the muscular exercise, is just the focus and concentration, and it has got a mindfulness aspect to it. So there is evidence from some studies of meditation that meditation can have some metabolic effects on the body, immune effects and so on. But what they've looked at in ice baths is you've got these little short-acting hormones that act between white blood cells in the immune system and other cells within the immune system. And they have, they claim, measured differences in these cytokines which could have an anti-inflammatory effect on the immune system.
Tegan Taylor: Cytokines is just one of the factors in the immune system.
Norman Swan: That's controversial. Other people have not found that. Some people have suggested that the metabolic effect of ice baths is similar to taking, say, prednisone, an anti-inflammatory drug. It may affect how genes produce proteins. There are all sorts of theories. Let me say that when scientists don't understand the reason for something but they observe an effect, they'll find all sorts of theories to explain it. And as one scientist once told me, it actually doesn't matter what the mechanism is; if it works, it works. So there probably is some kind of anti-inflammatory effect of cold exposure, but that appears to be about it at this stage of research.
Tegan Taylor: Well, I mean, there is other research underway as well, and so one study that's just started, a pilot study in Adelaide is looking at whether the Wim Hof Method could help with endometriosis pain. So there's all sorts of potential applications. Whether the evidence is there or not remains to be seen, because the study hasn't gotten underway yet.
Norman Swan: Pain would make a lot of sense, because the process of relaxation, focusing your mind on something else, which is the meditative process, and the counter-irritation effect of ice baths could well have an effect on pain, because pain is a brain thing. Endometriosis causes inflammation and pain in the pelvis or wherever the tissue is, but also has an effect on the brain, and if you can affect either, which is the inflammation at the level of the endometriosis or the perception in the brain, either way you're going to help.
Tegan Taylor: So kind of sticking with the brain/pain side of things, the claimed mental health benefits…you were saying when you went for the ice bath most people were there for the mental health side of things rather than for physical health,
Norman Swan: Yeah. And I have to say, the high of doing it lasted longer than the day, you know, I felt good for a few days afterwards. And the more I told the story of doing it, the more I felt better.
Tegan Taylor: I mean, being able to tell a story about when you were a hero does feel very good indeed. The question that I have for you, because this was February 2023 that you did it, and if you really believed in the benefits, surely you would have gone back for more?
Norman Swan: Yeah, I thought once was enough.
Tegan Taylor: He's still riding that high a year and a half on.
Norman Swan: That's absolutely right.
Tegan Taylor: So it sounds like there are some benefits, anti-inflammatory, maybe the mental health side of things, maybe pain management, but there's also risks, as you said.
Norman Swan: That's right. So the key here…and we often say this on What's That Rash?, which is if a little is good for you, don't think a lot is going to be better for you. Be careful of the dose. And most people who conduct responsible ice bath classes will only let you in for a couple of minutes. And don't think that sitting in for 15 minutes like Wim Hof is going to be necessarily good for you. Short, sharp, and by all means repeated, but don't stay in for too long.
Tegan Taylor: So bottom line for Sue; is it worth it?
Norman Swan: Yeah, well, why not try it and see? But read the small print in the safety waiver.
Tegan Taylor: How long was the safety waiver that you signed?
Norman Swan: It was about a page. I think it was mostly designed to say; if you're an idiot, don't do it.
Tegan Taylor: Good to know. Well, Norman, thank you for putting your body on the line for science. I feel like you and me are pretty much square now that you've done the ice bath challenge and I had a single tablespoon of apple cider vinegar in a glass of water a couple of weeks ago.
Norman Swan: Yeah, and let's go to our feedback now, because we've had lots of feedback on our show on sleep.
Tegan Taylor: So the question for our episode that we did on sleep a few weeks ago was basically whether you can train yourself to sleep less. And we talked about the fact that there is science to show that a few, like a small subset of people, genuinely need less than seven to nine hours of sleep a night. And I asked if anyone in our audience was in…and we have so many (they're called sleepless elites) in our audience that have been writing in.
Norman Swan: Yeah, I think we've given them bragging rights.
Tegan Taylor: So Adam has emailed in saying that he generally goes to sleep sometime between 12 and 2am and wakes up between 5am and 6am and feels normal, able to function properly. And even as a small child he didn't sleep as much as other kids. Oh, and he has been a high achiever his entire life, doing well at university and school, now a director of his own engineering company. So he's obviously not suffered from his lack of sleep, at least not yet.
Norman Swan: And he was a nightmare as a small child.
Tegan Taylor: Oh man, a baby that doesn't nap is such hard work.
Norman Swan: That's right, he says that his mum said he didn't sleep during the day. My God.
Tegan Taylor: Adam, can you tell your mum, you know, I feel that, and I hope she's okay. And Matt has written in to scold us for not mentioning parents of young children as a group that should have been studied, not just the military. And for that, Matt, I apologise deeply, because yes.
Norman Swan: And he says 'I'm definitely still sleep deprived, but I've somehow trained my body and brain to function at a level capable of dealing with whatever surprises the days throw at me.' Great parenting there, Matt, and let me tell you, 20 years from now it'll all be fine.
Tegan Taylor: But I feel like I felt the same way when my kids were really little, that I always thought I was like a nine-hours-a-night girly, and then when you realise that you actually can function on less, it's a nice feeling to think that you're actually stronger than you thought. But now that my kids are older, I very happily go to sleep and I sleep all night long.
Norman Swan: Yeah, and whatever time you listen to the podcast, send us your questions to thatrash@abc.net.au. Do subscribe to us, and we'll see you next week.
Tegan Taylor: See you then.
