Critics turn up heat on cryotherapy claims

It's the latest alternative health fad made popular by athletes and Hollywood types. It's also in the news because a young woman was tragically found dead recently in a cryotherapy tub. The practice purports a bunch of health benefits, from acting as an anti-ageing remedy to recovering quicker from sport injuries. But what is it and what's the science behind this new trend? Dr. James Hamblin, who also writes a health column for the Atlantic, helps us weed through the buzz.

This interview has been edited for clarity and length.
    
Brent Bambury: I know you've experienced a cryotherapy session because I saw a video of it. But would you describe it to our listeners? What happened to you?

James Hamblin: I was asked to remove all my clothes except for my underwear and socks and then enter a chamber where -110 degrees celsius air was shot at my skin for 90 seconds. I endured it with a smile on my face and then I got out. And that's the end of it 

BB: The chamber kind of looks like a drink in a tiki lounge because there's air coming up over the top of it that's been frozen. Correct?

JH: Right. That's sort of a visual effect that makes it look like you're being boiled in a pot alive. But, in fact, it's very cold.

BB: Aside from feeling cold, how did it make you feel? What were some of the benefits you might have received from it?

JH: So, it was very similar to going outside on the coldest day in winter without a shirt on. Your body starts to go into a little bit of a fight or flight mode. The adrenaline is pumping through you. The blood is surging to your core away from your skin, saying, "OK. You know your skin might get frostbite here but I'm going to protect your liver and your heart and try to keep you alive." 

BB: Were you worried though? I mean frostbite's a real threat. Do you think there's anything about the system, about the way that it's set up, that you could have been exposed to frostbite?

JH: So, if any of the garments you are wearing, your underwear, your socks, have moisture in them that will freeze then the conductance between that ice and your skin causes frostbite. I was just very vigilant. I had a towel and wiped down my armpits five times before I got in there. 

BB: You survived but Hollywood loves this stuff. They're on board and so are some professional athletes. What are the proposed or the purported health benefits of cryotherapy? 

JH: If you look at the actual marketing from a lot of these cryotherapy purveyors, it's pretty insane. The one I went to, Kryolife in New York, promises cellulite reduction, boosted metabolism, better skin, anxiety, depression, fatigue, insomnia, migraines. Pretty much anything you can think of, this is supposed to help with. 

BB: Those claims are coming into question, especially now that this practice is making headlines. But, is there any science to back up any of those claims whatsoever? 

JH: None. None of those claims at all. It's a very difficult thing to study because you can't give someone a placebo treatment. People are going to know if they're going through this. 

BB: If they're cold.

JH: Yeah. Yeah. And immediately afterward there's a logical idea... OK. You got a rush of endorphins. So, if you're feeling depressed now you're thinking, 'Oh, I'm just glad to have survived. I'm out of my head for a moment.' So, there's something possibly, potentially, to it but no good long-term studies on all of that. All that we have is that it's a possible mechanism for muscle soreness in endurance athletes.

BB: But that's significant isn't it because for many generations now we've been treating soft tissue injuries and strains with ice baths or ice packs? Isn't that a possible benefit, even if it hasn't been scientifically proven yet?

JH: The idea that you could use cryotherapy instead of an ice bath is a legitimate one for a pro athletic team that could afford one of these chambers. They say that it's more comfortable than going into an ice bath and it takes less time. Technically the conductance from your skin to water is going to make you much colder than air, even if the air is colder than that ice water. People prefer it maybe because they're actually getting less cold then if they jumped into an ice bath. 

BB: Then why aren't there more studies on cryotherapy considering that it's becoming so popular? 

JH: It is just very new, especially to the mainstream, and was only really intended by the purveyors to be for endurance athletes at the outset. 

BB: And, as you say, you can't have a placebo because there's no placebo sample available for you?

JH: Right. You're sort of just extrapolating logical mechanisms from things that have been studied with icing injuries and people getting into an ice bath, which themselves have conflicting amounts of evidence as to how beneficial they really are. We know that for acute injuries, cryotherapy...It's good to define the terms between whole body cryotherapy and local cryotherapy, like putting ice on a sprained ankle which we've been doing for a long time. We know that works after an acute injury. But doing it a week later, there's no benefit. 

BB: Why do you think without hard scientific research and hard evidence cryotherapy has caught on among pro sports teams, which presumably have very talented doctors and medical personnel on board with them? 

JH: It is a more desirable proposition to stand in there for 90 seconds and have all that air blown at you then to jump into an ice bath which is a terrible experience. Then you get a little bit a buzz going. You get some hype. You get people who say it makes them feel better. So, it spreads like any kind of trend. A fashion trend. A food trend. 

BB: Does it remind you of previous fads or trends about health and well being? 

JH: Oh, absolutely. They're all very similar. They sort of start with an elite population of people, then trickle down and expand the uses and the claims that are made about these things, like the gluten free trend. You could even link to that. There are people with celiac disease who definitely need to avoid gluten or they'll become seriously ill. But then it gets extrapolated. 'Oh, well, why doesn't everyone avoid gluten and maybe it'll help with your anxiety and depression, even if you don't have celiac disease. And, this is the sort of thing where it's just...Yes, it might have some benefit to elite athletes immediately after an intense workout, and now you have people paying $90 to potentially feel slightly less anxiety. 

BB: That's a lot of money to spend for what was a three minute exposure for you. 

JH: I did the ninety seconds. You can go up to three minutes. I said no. I'm going to stick to 90 seconds. That's all I'll tolerate. Yeah, that's a lot of money for something really comparable to just going outside in the winter and it being available for free if you wanted to. 

BB: And this is Canada and winter is coming. 

JH: Well, then you have cryotherapy right outside your door.