Speaker 1: Hey, please take a second and leave us a review
Speaker 1: on Apple Podcasts, Spotify, or wherever you listen to the podcast.
Speaker 1: Thanks a lot. Hey, welcome to Science Stuff, a production
Speaker 1: of iHeartRadio. I'm hort Jam and today we're answering the
Speaker 1: question can we hibernate humans? We know bears can do it,
Speaker 1: some birds can do it, and even lemurs can do it.
Speaker 1: But could we get a person to hibernate? And would
Speaker 1: it lead to breakthroughs in emergency medicine, cancer research, and
Speaker 1: even space travel. We're gonna talk to a biologist who's
Speaker 1: been studying hibernation in animals for thirty years, as well
Speaker 1: as a medical researcher who's been working with the European
Speaker 1: Space Agency to see if this would let humans travel
Speaker 1: to distant stars. So get nice and cozy and get
Speaker 1: ready to enter a state of science torpor as we
Speaker 1: answer the question can we hibernate humans? Hey? Everyone do?
Speaker 1: They were asking three questions, what is hibernation, can we
Speaker 1: get it to work in people? And why would we
Speaker 1: want to hibernate a person? It turns out there are
Speaker 1: a lot of reasons why we would want to do that,
Speaker 1: including maybe letting us explore the cosmos, but first we
Speaker 1: need to understand what it is and how animals are
Speaker 1: able to do it. So my first conversation was with
Speaker 1: Professor Kelly Drew.
Speaker 2: So, my name's Kelly Drew. I am a professor at
Speaker 2: the University of Alaska, Fairbanks, and I direct a NIH
Speaker 2: funded center called the Transformative Research and Metabolism. So I've
Speaker 2: studied hibernation for about thirty years, so I'm very much
Speaker 2: focused on the brain and hibernation.
Speaker 1: Incredible. I think you're the perfect person for us to
Speaker 1: talk to you today.
Speaker 2: Awesome.
Speaker 1: Maybe start us off, how do you define hibernation? What
Speaker 1: is it?
Speaker 2: Well, the big picture of hibernation is that it's a
Speaker 2: metabolic adaptation where it suppresses metabolism and body temperature because
Speaker 2: sometimes they need to conserve that energy if food is
Speaker 2: not available, and many animals do it. Everything from some primates.
Speaker 2: There's the fat tailed lemur from Madagascar. There's marmots. Bears hibernate,
Speaker 2: not polar bears. Polar bears don't hibernate because they have
Speaker 2: food year round because they fish off the ice, but
Speaker 2: black bears and grizzly bears hibernate. And then there's ground
Speaker 2: squirrels and hamsters, even the common house mouse. If you
Speaker 2: take its food away, it will hibernate. Hummingbirds will hibernate.
Speaker 1: Hummingbirds.
Speaker 2: Yeah, there's a lot of different species.
Speaker 1: Yes, hummingbirds hibernate too. Okay. The big question I had
Speaker 1: for doctor Drew was how is hibernation different from sleep?
Speaker 2: Actually is thought to be an extension of sleep, So
Speaker 2: at least with hibernation, animals have to sleep to enter hibernation.
Speaker 2: And what I think is that there's a process that
Speaker 2: kind of flips a switch that allows the temperature to
Speaker 2: continue to cool, and then cold by itself plays a
Speaker 2: role in suppressing metabolism.
Speaker 1: So hibernation is not just sleep. Something else kicks in
Speaker 1: in animals during hibernation, and that causes two things to happen.
Speaker 1: One through metabolism, meaning how active the cells in their
Speaker 1: body are slows down. And two, their body temperature drops.
Speaker 1: And this is a key feature of hibernation because normally
Speaker 1: your body doesn't let your body temperature go down. Even
Speaker 1: when you sleep, your body doesn't drop below one or
Speaker 1: two degrees of its normal temperature. It's all part of
Speaker 1: our survival mechanism.
Speaker 2: We all have a point where if we get to
Speaker 2: a certain temperature, our bodies kick in the keaters, humans
Speaker 2: will shiver, we start generating heat. And so the trick
Speaker 2: is that during hibernation, your body allows it to get
Speaker 2: a little bit colder than what we normally do. So
Speaker 2: it's often thought of as well, you just lower the thermostat,
Speaker 2: reset the set point on the thermostat, and you get
Speaker 2: down to a colder temperature, and that temperature helps to
Speaker 2: suppress metabolism. So you go into this kind of state
Speaker 2: of nirvana, very low energy consumption, and everything just sort
Speaker 2: of quiets down.
Speaker 1: I see. So once we go into tibernation, our set
Speaker 1: point is set lower, and so the body gets colder
Speaker 1: and that doesn't do any harm to the organism.
Speaker 2: Well, the ground squirrel is especially adapted to cold tissue temperature.
Speaker 2: For humans, if our bodies go below about thirty degrees celsius,
Speaker 2: then we can have cardiac arrhythmias, so the heart doesn't
Speaker 2: function all that well. But the ground squirrels are specially
Speaker 2: adapted and their body temperature goes down actually to minus
Speaker 2: three degrees below freezing, wow, minus three celsius, and they
Speaker 2: have no trouble with that.
Speaker 1: So Hibernation isn't just about slowing your heart rate or
Speaker 1: going to sleep for a long time. Something really fundamental
Speaker 1: happens to animals that hibernate. Their entire bodies recalibrate to
Speaker 1: work at a lower temperature, which is something that normally
Speaker 1: our bodies very strongly rejects. I mean, if you go
Speaker 1: below thirty degrees celsius or eighty six degrees fahrenheit, as
Speaker 1: doctor Drew said, your heart basically stops working. But animals
Speaker 1: that hibern need have a special mechanism that lets them
Speaker 1: run super cold.
Speaker 2: And so the ground squirrels have adapted these temperature mechanisms
Speaker 2: so they keep things functioning even in the cold. I
Speaker 2: mean the same thing in your car. You know, you
Speaker 2: change the weight of your oil for winter compared to summer,
Speaker 2: so you want a little bit less viscous oil in
Speaker 2: the winter.
Speaker 1: I see, I live in California and I'm from Panama,
Speaker 1: so this is need to me, that's the in fact
Speaker 1: that you need to change your oil. But in Alaska,
Speaker 1: I imagine that's a common thing.
Speaker 2: Very common. Yes, So all those kinds of things. Animals
Speaker 2: have adaptations that allow them to tolerate different temperatures, and
Speaker 2: we don't know really what all those are.
Speaker 1: Okay, here I had a lot of questions for doctor Drew,
Speaker 1: like what's happening in the brain of these animals when
Speaker 1: they hibernate, Do they dream or are they conscious? What
Speaker 1: triggers this hibernation mechanism? And then what's going on in
Speaker 1: the brain while animals are in the state.
Speaker 2: Well, like I said, they are first sleeping, but as
Speaker 2: they cool, the magnitude of the brain waves they shrink
Speaker 2: and get lower and lower as the animal cools, until
Speaker 2: finally it becomes flat. And that actually looks somewhat like
Speaker 2: being in a coma, but they're not in a coma
Speaker 2: because they can be induced to arouse just by handling.
Speaker 1: But it's more extreme than sleeping for example.
Speaker 2: Right, Yeah, it's a different state of consciousness. So cold
Speaker 2: really continues to dampen the brain waves so that then
Speaker 2: they will become flat.
Speaker 1: Meaning like the brain doesn't work at those lower temperatures.
Speaker 2: You don't see any electrical activity.
Speaker 1: That means, so basically the brain of the animal stops working.
Speaker 1: It's almost being brain dead, but not quite. In fact,
Speaker 1: it's something very different. Amazingly hibernating animals have been shown
Speaker 1: to be able to learn while they hibernate.
Speaker 2: And they can learn actually when they're in this state.
Speaker 1: Wow, what do you mean they learn? How can they
Speaker 1: learn if they're passed out?
Speaker 2: What they learn is they habituate to handling. If you're
Speaker 2: like needing to do something with the animal when they're
Speaker 2: in hibernation, you can just handle them, and at first
Speaker 2: they'll be bothered by it, and they'll start to wake up.
Speaker 2: And if you do that over and over, they pretty
Speaker 2: much get used to it to where they just don't
Speaker 2: bother anymore. They're used to it. If you go in
Speaker 2: and handle them, they won't arouse. Wow, And so we
Speaker 2: consider that to be learning. It's called habituation.
Speaker 1: Oh wow, that's uds like my teenage son when you're
Speaker 1: trying to.
Speaker 2: That's exactly it.
Speaker 1: Yeah, even though their brain activity is totally flat and
Speaker 1: they seem like they're in a coma or brain dead,
Speaker 1: the hibernating animal can still somehow process what is happening
Speaker 1: to it. It's really a very different state of being. Okay.
Speaker 1: The next question I had was what triggers hibernation.
Speaker 2: We've got animals that hibernate according to season. We call
Speaker 2: them obligate hibernators. So they have a clock in their
Speaker 2: bodies that tell them what time of year it is,
Speaker 2: and no matter whether it's cold or dark, or whether
Speaker 2: they have food or don't have food, they will hibernate.
Speaker 2: And those are the ground squirrels and other species like
Speaker 2: the hamsters are what are called facultative hibernators, and for those,
Speaker 2: the hibernation has to be induced by short days, so
Speaker 2: like what you would see in winter. Other animals like
Speaker 2: mice will hibernate just because they don't have food. It's
Speaker 2: just simply, hey, we don't have any food. Let's chill
Speaker 2: for a while as long as we can, and then
Speaker 2: we're gonna warm up again. See if there's any food.
Speaker 1: Oh, I see, let's just wait it out and see
Speaker 1: what happens. Yeah, what about like bears.
Speaker 2: And bears are a little bit more facultative because if
Speaker 2: it's warm, they won't hibernate. If they have a whole
Speaker 2: lot of food, they don't hibernate. So bears, because they're
Speaker 2: so big, they don't actually get that cold. They don't
Speaker 2: get colder than about thirty degrees see, but they suppress
Speaker 2: their metabolism down to twenty five percent of basil metabolic rate.
Speaker 2: So basil metabolic rate is as low as you can go.
Speaker 1: If you go lower, you're dead.
Speaker 2: Kind of, yeah, you're dead.
Speaker 1: Would you say? That's kind of a definition of hibernation
Speaker 1: is let you basically slow your body down to where
Speaker 1: you would normally be.
Speaker 2: Dead, exactly right. And lots of people like to think
Speaker 2: of it as near death, and that way is very similar,
Speaker 2: and we like to imagine that hibernation is a state
Speaker 2: that kind of is near death, but it can be reversed.
Speaker 1: All right, When we come back, we're going to talk
Speaker 1: about another interesting fact site to sit found about hibernation,
Speaker 1: and then we're going to talk about whether we could
Speaker 1: ever make it happen in humans. Don't go anywhere, we'll
Speaker 1: be right back. Hey, welcome back. We're talking about hibernation
Speaker 1: and whether we could ever do it in humans. And
Speaker 1: so far we've learned what hibernation is, which animals do it,
Speaker 1: what triggers it, and whether animals dream while they hibernate.
Speaker 1: The last thing we're going to talk about before we
Speaker 1: get to hibernation humans is that hibernation in animals is
Speaker 1: not constant. There's a cycle in hibernation.
Speaker 2: And for whatever reason we don't understand animals when they
Speaker 2: go colder than thirty degree c they have to rewarm
Speaker 2: every so often. Hamsters will rewarm every three to four
Speaker 2: five days. Ground squirrels rewarm every two to three weeks,
Speaker 2: and we call these interbout arousals. And during that interbout arousal,
Speaker 2: they sleep, so the flat eeg turns into slow wave sleep.
Speaker 2: They make glucose, they urinate just a little bit, they
Speaker 2: fluff up their nest, and they sleep and then they
Speaker 2: re enter torpurth.
Speaker 1: Torpor, by the way, is what scientists call that deep
Speaker 1: low metabolism, cold temperature, almost brain dead state animals enter
Speaker 1: during hibernation. But what doctor Drew is saying is that
Speaker 1: animals are not in that state the whole time. They
Speaker 1: kind of stir and kickstart their body every so often
Speaker 1: throughout the hibernation period, and scientists think animals do this
Speaker 1: to kind of do body maintenance.
Speaker 2: Something initiates that in about arousal. That evidence suggests that
Speaker 2: it's either an accumulation of something a waste that they
Speaker 2: have to get rid of, or a lack of metabolite
Speaker 2: that they need, like for example, glucose and so they
Speaker 2: need to make glucose and they can't do it when
Speaker 2: they're cold. So during hibernation, they may need to warm
Speaker 2: up to make glucose. They may need to warm up
Speaker 2: to get rid of nitrogen somehow, And so that's what
Speaker 2: we think is that they have to warm up periodically
Speaker 2: to do some of that metabolic work.
Speaker 1: So you're saying built into hibernation is this sort of
Speaker 1: periodic arousal where they do a little bit of maintenance
Speaker 1: and then they go back to hibernation.
Speaker 2: That's right, that's right.
Speaker 1: All right, And now we get to the topic of
Speaker 1: making humans hibernate. And the first question you might have
Speaker 1: is why hibernate a human? Well, according to doctor Drew,
Speaker 1: there are many reasons why we would want to put
Speaker 1: humans in a deep state of torpor. Okay, why would
Speaker 1: we want to hibernate humans?
Speaker 2: Well, the most lowest hanging fruit is for critical care,
Speaker 2: particularly for brain injury. Like if you have a cardiac
Speaker 2: arrest that means like sudden heart failure, you fall on
Speaker 2: the ground and now you're comatose and you get resuscitated
Speaker 2: by CPR. Those people actually wouldn't know it, but they
Speaker 2: ultimately die from brain injury. So even though they can
Speaker 2: bring them back, the brain doesn't tolerate that lack of
Speaker 2: blood flow very well. So if we can induce hibernation,
Speaker 2: there's potential that it could have immediate benefit to people
Speaker 2: that suffer stroke or cardiac or risk drowning or lack
Speaker 2: of oxygen.
Speaker 1: How would that help them, Well, it may.
Speaker 2: Just simply prevent the injury caused by the lack of
Speaker 2: blood flow, or it could stabilize the injury while every
Speaker 2: other processes kind of come back to normal and then
Speaker 2: allows the body to kind of deal with it at
Speaker 2: a slower pace at a better time.
Speaker 1: Meaning you just want to slow everything down so that
Speaker 1: the injuries don't get worse.
Speaker 2: Yes, right, having them enter this hibernation natural cooling state
Speaker 2: is expected to be more beneficial.
Speaker 1: I see. So that's one reason we might want to
Speaker 1: hibernate a person in an emergency. Going into hibernation could
Speaker 1: cool the body down going into hypothermia, and that would
Speaker 1: slow the response to the body so that doctors have
Speaker 1: more time to deal with the injury. And this could
Speaker 1: be useful not just in heart attacks and strokes, but
Speaker 1: in any kind of injury where medical care is not
Speaker 1: easy to get.
Speaker 2: So you could stabilize somebody by putting them into a
Speaker 2: hibernation state, and how you can get them to medical facilities.
Speaker 2: It certainly battlefield operations. Same with remote emergency care. If
Speaker 2: somebody falls mountain climbing or whatever and is injured but
Speaker 2: they can't be evacuated for a period of time, they
Speaker 2: could be stabilized by putting them into these states.
Speaker 1: And another interesting reason to hibernate people is to maybe
Speaker 1: save the planet, he said, saving the planet. What's the
Speaker 1: scenario there?
Speaker 2: So the other kind of grandiose ideas I've heard. One was, well,
Speaker 2: we can save the planet if you know, we can
Speaker 2: just all chill on a regular basis. We don't drive
Speaker 2: as much, we don't use as much electricity, all these things.
Speaker 1: Like we would all go into hibernation every once in
Speaker 1: a while or every night or what do you mean?
Speaker 2: Yeah, maybe for you know, like life holidays, Yeah, a
Speaker 2: couple of weeks at a time. I think it was
Speaker 2: inspired by COVID a little bit, because as horrible as
Speaker 2: it was, we definitely saved some things. You know, traffic
Speaker 2: was less and pollution lowered, wasn't so bad. People get
Speaker 2: pretty engaged in the life and hard to say, well,
Speaker 2: I'm just going to cut out for a couple of
Speaker 2: weeks or a month.
Speaker 1: Yes, we could take hibernation vacations. Say you just want
Speaker 1: to check out for a few days or a few months,
Speaker 1: you could hibernate, and overall we would reduce human activity,
Speaker 1: which could be good for the planet. I mean, how
Speaker 1: many of us would like to take a break right
Speaker 1: now and not wake up until the next presidential election.
Speaker 1: And doctor Drew says taking hibernation vacations wouldn't just reduce
Speaker 1: your carbon footprint, it could actually help you dage and
Speaker 1: live longer.
Speaker 2: But what's interesting and hybridating animals is they do live longer.
Speaker 2: Hibernation prolongs life, but you just kind of a pause.
Speaker 2: It's not the wear and tear on the body. You're
Speaker 2: really taking a break and cooling and rewarming. There's evidence
Speaker 2: that it has some regenerative properties, so you can actually
Speaker 2: you know, regenerate synapses, potentially regenerate muscle. But certainly in
Speaker 2: hibernation is interesting because even though they don't eat or
Speaker 2: move for eight months, they wake up strong. Whoa, they
Speaker 2: don't lose any muscle.
Speaker 1: So they live longer, not just because they pause their body.
Speaker 1: But because there's other benefits to hibernation.
Speaker 2: There could be that's still a hypothesis, but we're seeing
Speaker 2: evidence of cold and rewarming. The combination of cooling and
Speaker 2: rewarming stimulates regenerative processes.
Speaker 1: I see. You would think that it's just your body
Speaker 1: kind of goes downhill when you're hybrided. But now there's
Speaker 1: something stimulating about hibernation. Yeah, fascinating.
Speaker 2: But you know it's also a wonderful weight loss program.
Speaker 1: What do you mean, what do you mean.
Speaker 2: Well, you don't eat, metabolism is down These ground squirrels
Speaker 2: can double their body weight pre hibernation and then they
Speaker 2: lose all of that by spring, but they're fit and
Speaker 2: trim when they wake up.
Speaker 1: Oh wow, that does sound like a really good program.
Speaker 1: Well I am all in on that startup. Right, that's
Speaker 1: Fitness Life Extension. Where do I sign a check for
Speaker 1: that investment?
Speaker 2: Exactly?
Speaker 1: That's right. You could use hibernation to lose weight during
Speaker 1: hibernation and the most burnt fat to stay alive. And
Speaker 1: so you could imagine going into hibernation for a while
Speaker 1: and waking up thinner without having to diet or exercise. Okay,
Speaker 1: the last super interesting reason to hibernate people is for
Speaker 1: space travel. You've all seen the science fiction movies where
Speaker 1: astronauts climb to a sleeppond and going to suspended animation.
Speaker 1: But why is that? How does hibernation help with goin
Speaker 1: as space? To find out, I talked to a medical
Speaker 1: researcher that's been working with the European Space Agency on
Speaker 1: this idea. Well, thank you, doctor Huk for joining us.
Speaker 3: It's my pleasure. I'm very curious a lot your questions
Speaker 3: and to explore with you together, you know, the new
Speaker 3: perspectives of potential hibernating humans.
Speaker 1: One day, can you please tell us who you are
Speaker 1: and what you do.
Speaker 3: I'm a physician by training during research and mostly about
Speaker 3: organ protection, which has brought me to this field of
Speaker 3: spaceflight and how the organisms reacting to extreme environments.
Speaker 1: Okay, now, according to doctor Chuk, there are several reasons
Speaker 1: why being able to hibernate would help humans travel through space. Now,
Speaker 1: you probably think the main reason is the one you
Speaker 1: see in movies, which is that space is huge and
Speaker 1: it takes a long time to get anywhere. For example,
Speaker 1: the near start to us Proximus centory is forty trillion
Speaker 1: miles away and getting there could take hundreds or even
Speaker 1: thousands of years. So being able to climb to a
Speaker 1: pod and somehow good sleep and stop aging means you
Speaker 1: could actually survive the trip. This is true. But actually
Speaker 1: NASA and the European Space Agency are interested in hibernation
Speaker 1: for more practical reasons, and they're looking at it as
Speaker 1: a strategy for shorter journeys like say to Mars. Getting
Speaker 1: to Mars takes a little less than a year. So
Speaker 1: why would we need to hibernate? Well, like I said,
Speaker 1: there are several reasons, and the first is that when
Speaker 1: you're hibernating you don't need to eat as much. You said,
Speaker 1: there are big advantages in terms of resources. Can you
Speaker 1: explain what that means?
Speaker 3: Yeah, we did a study with the European Space Agency.
Speaker 3: We designed the mission of six people going to Mars
Speaker 3: and back just theoretical design. What do would that mean?
Speaker 3: How much resources do we need? How much oxygen, how
Speaker 3: much water supply, food supply, so on. What would be
Speaker 3: the scenarios of being under hibernation condition versus another high
Speaker 3: condish And of course oxygen you save a lot, but
Speaker 3: the most tracking element is for food. For instance, you
Speaker 3: have maybe a twenty percent of fifteen percent of food needed.
Speaker 1: Only Doctors huqu In the European Space Agency calculated that
Speaker 1: for a six percent mission to Mars, where everyone stays
Speaker 1: awake the whole time, you need to bring about six
Speaker 1: tons of food, which is six thousand kilograms or about
Speaker 1: thirteen thousand pounds of food. And that's because the whole
Speaker 1: trip would take about two years, and so you need
Speaker 1: over two thousand, two hundred meals for six adults, and
Speaker 1: there are no grocery stores along the way, so you
Speaker 1: have to bring everything. But then they compared that to
Speaker 1: a Mars mission in which the crew hibernated some or
Speaker 1: all of the way there and back, and the amount
Speaker 1: of food you need in that case turns out to
Speaker 1: be only seven hundred kilograms, or about fifteen percent of
Speaker 1: the original amount. That's about five tons of payloads that
Speaker 1: you don't need to bring. If you hibernate the crew,
Speaker 1: you only need sixty seven hundred kilograms.
Speaker 3: Wow, exactly. This makes the difference. And when you just
Speaker 3: think about the implementation of a travel to Mars, you
Speaker 3: just need less payloads. Yeah, so this is why agencies
Speaker 3: maybe like it. Yeah, yes, we reduce the payloads. You
Speaker 3: need less stuff to get uploaded, and every kilochrome every
Speaker 3: pound costs a lot of money.
Speaker 1: So hibernation would make space travel cheaper. Another reason hibernation
Speaker 1: would help going to space is that hibernation apparently makes
Speaker 1: you more immune to radiation damage. Space is full of
Speaker 1: harmful radiation, some of which comes from the Sun and
Speaker 1: some of which comes from cosmic rays, but it's a
Speaker 1: real problem for astronauts. It means that your chances of
Speaker 1: getting cancer out in space are much higher than if
Speaker 1: you stay on Earth. But for reasons that scientists aren't
Speaker 1: quite sure of, going into hibernation makes you more radiation.
Speaker 3: When you relief of vicinity and go the younger fun
Speaker 3: old belt and having less protection, you will see more
Speaker 3: radiation effects there it will increase, and depending on solar eruptions,
Speaker 3: this may even be detrimental. So radiation resistance is a
Speaker 3: big thing.
Speaker 1: Doctor Chuke says that scientists in Germany and Italy have
Speaker 1: done experiments where they induce torpor in test animals and
Speaker 1: they found that it kind of protects them from radiation damage.
Speaker 1: And the reason for that is not quite clear to scientists.
Speaker 1: Some think it's because your cells are not multiplying as much,
Speaker 1: so there's few chances for the radiation to cause inmutation.
Speaker 1: But it could also be because during hibernation, the body
Speaker 1: is better at repairing itself. And this brings up another
Speaker 1: reason hibernation could help in space travel, and that is
Speaker 1: what we mentioned before in animals. When animals hibernate, they
Speaker 1: don't lose bone or muscle mass. Hibernating animals wake up
Speaker 1: trim and fit and ready to go. But human bodies
Speaker 1: when they're in space start to go downhill and deteriorate fast.
Speaker 3: When you stay lower in space, the problems may really
Speaker 3: kick off. It might be either the conditioning of the
Speaker 3: body so you're not experiencing gravity, pull on your bone,
Speaker 3: on your muscle, so you get rid of some volume
Speaker 3: that you don't need. The bones are gone muscles. Yeah,
Speaker 3: there was a research paper summarizes you need a new
Speaker 3: skeleton in the closet when you leave this even when
Speaker 3: you survive. But because your bones get really weak because
Speaker 3: of this deconditioning effect that you don't challenge your body.
Speaker 3: And if you had the chance to put someone in hibernation,
Speaker 3: these degenerated processes would stop, yeah, or would be wow,
Speaker 3: maturely reduced.
Speaker 1: I hadn't thought about that. So we've seen that in animals.
Speaker 1: Animals don't lose bone or muscle.
Speaker 3: Exactly, they don't lose bone and muscle and wake up
Speaker 3: and up back to the business.
Speaker 1: So to say, clearly, being able to hibernate humans would
Speaker 1: be a game changer for space travel. You could imagine
Speaker 1: hopping on a spaceship going into hibernation, and when you
Speaker 1: wake up, you're in Mars, and not only are you
Speaker 1: well rested and less damaged by radiation, but you feel great,
Speaker 1: maybe even in better shape than when you went to sleep.
Speaker 1: So now the question is can we actually do it
Speaker 1: in humans? Is it actually possible to hibernate people? When
Speaker 1: we come back, we'll ask our two experts this question.
Speaker 1: We'll find out what scientists have done to make this happen.
Speaker 1: Don't go anywhere, we'll be right back, and we're back.
Speaker 1: We're talking about the possibility of hibernating humans, and so
Speaker 1: far we've talked about how hibernation worksimals and what are
Speaker 1: some of the reasons we would want to make it
Speaker 1: happen in people. It could help with emergency medicine, producing
Speaker 1: our carbon footprint and may even have health benefits. It
Speaker 1: could also be a game changer for space travel. We
Speaker 1: heard from doctor Alexander Chuquet, a physician that works with
Speaker 1: the European Space Agency, on what space does to the
Speaker 1: human body, and he listed some of the advantages hibernation
Speaker 1: could bring two long space journeys. The last advantage we'll
Speaker 1: talk about is that it could help keep astronauts sane
Speaker 1: on their way to Mars.
Speaker 3: So it takes about two years to go back and forth,
Speaker 3: which means you are isolated and confined for this period
Speaker 3: of time together with your colleagues in a small habitat.
Speaker 3: So they are adding a lot of psychological factors to it.
Speaker 3: There's even a syndrome called the Earth out of side syndromes.
Speaker 3: When it's just anticipating, you see the Earth going p sized.
Speaker 3: When you are landing on Mars. You can just see it,
Speaker 3: but it's very far away and you may imagine and
Speaker 3: not long it will take to be rescued or there's
Speaker 3: an issue. So there are a lot of factors which
Speaker 3: are added. And this is too interesting because there are
Speaker 3: different levels to add on top and on top, and
Speaker 3: the question is always how much can we overcome, how well,
Speaker 3: can we deal with these sum up stressors and how
Speaker 3: is the body able to compensate. You may compensate for
Speaker 3: the one, you may comment for the other, but some
Speaker 3: effects and no one really knows because no one has
Speaker 3: ever experienced such a long voyage.
Speaker 1: What Doctor should Care is saying is that going to
Speaker 1: space is stressful. You're always in mortal danger, far far
Speaker 1: away from any help, and on top of that, you're
Speaker 1: stuck in a small space with other people and there
Speaker 1: could be drama if tensions get high. So being able
Speaker 1: to hibernate for most of that journey to Mars could
Speaker 1: really help everyone stay sane. Okay, and now we come
Speaker 1: to the big question, which is can we make hibernation
Speaker 1: work in humans? Well, according to doctor Kelly Drew, there
Speaker 1: are people I think this idea using drugs. So then
Speaker 1: what's the prospect of doing this in humans? What do
Speaker 1: we know about whether we can induce it as it worked?
Speaker 2: Well, there is a lab that is funded by NASA
Speaker 2: at the University of Pittsburgh and run by clinician named
Speaker 2: Cliff Collaway, and they are working in people. They're using
Speaker 2: currently known drugs anesthetics that are good at turning down
Speaker 2: the thermostat. He's using an anesthetic called dex metatomidine, and
Speaker 2: he sees that it is the best of all the
Speaker 2: drugs used for cooling to suppress shivering. And they're measuring
Speaker 2: how much metabolic savings they can achieve and how comfortable
Speaker 2: people are when they're cold, and they're showing energy savings
Speaker 2: and it's not profound, but you know, we're also working
Speaker 2: on drugs that target the dentistin system.
Speaker 1: So a dentistine is a super important molecule that's used
Speaker 1: all over your body. It's involved in how we process energy.
Speaker 1: It's part of RNA and DNA, and it's a transmitter
Speaker 1: molecule in your brain. If you drink coffee or tea,
Speaker 1: caffeine wakes you up by blocking a dentisine in your neurons.
Speaker 1: And it also seems to be a part of hibernation.
Speaker 1: You can use it to trigger hibernation in animals or
Speaker 1: by blocking it you can delay an animal from hibernating.
Speaker 1: What doctor Dury is saying is that scientists are working
Speaker 1: on drugs that affect this adenosine molecule.
Speaker 2: And part of what we see is a little scary
Speaker 2: from a clinical perspective because there's very low blood flow,
Speaker 2: very low heart rate, but we are beginning to think
Speaker 2: that that is part of the metabolic suppression.
Speaker 1: What do you mean, it's scary because it is so
Speaker 1: close to death.
Speaker 2: It is so close to death, it really is. Yeah,
Speaker 2: So it has to be very well understood and very
Speaker 2: well monitored and you know known, because you know, we
Speaker 2: don't have all the adaptations that these ground squirrels have.
Speaker 2: We haven't already been optimized to tolerate the challenges of hibernation,
Speaker 2: and so we have to be very careful and understand
Speaker 2: it and know how to manage it so that it's
Speaker 2: you know, it's not risky.
Speaker 1: So we have been experimenting with making this work in
Speaker 1: humans and there are signs that it could work. But
Speaker 1: the hard part is that we're still not sure how
Speaker 1: the whole body process of hibernation should get started, because
Speaker 1: in a way, it has to start from inside the body.
Speaker 3: So hibernation it comes from your body. It's not external. Okay,
Speaker 3: it starts indulgeously. And this is what animals are doing.
Speaker 3: They have no drugs, nothing, They're just there and this
Speaker 3: is their mechanisms in start that we don't understand yet
Speaker 3: whether they start on the brain, whether they start on
Speaker 3: the cellar level, this is still open and under debate.
Speaker 3: Transferring this to the humans, I mean today we have
Speaker 3: no real real evidence that human is a hibernator, not
Speaker 3: at all. But we have also no evidence that who
Speaker 3: human cannot be a hibernator. So the mechanisms might be
Speaker 3: still inherited in us. However, how this may work is
Speaker 3: completely open.
Speaker 1: Now what's interesting is that there are examples of humans
Speaker 1: that can sort of go into hibernation. They're called yogis.
Speaker 2: You know, the best examples are yogi's. Really well practiced
Speaker 2: yogis can do this. I mean they can lower metabolism,
Speaker 2: lower blood pressure. They do that mostly through their breath
Speaker 2: and involves a parasympathetic nervous system. And that is something
Speaker 2: also that we see in hibernation is they definitely use
Speaker 2: their parasympathetic nervous system as they enter hibernation. So that's
Speaker 2: another nice human example of what's possible.
Speaker 1: I mean, yogis, this is real.
Speaker 2: This is not oh, this is real. This is these
Speaker 2: are you know, life practicing yogis that can lower body
Speaker 2: temperature and metabolism, heart rate dramatically, not eat for days.
Speaker 2: I don't know what the record is. It's not in
Speaker 2: the literature as much as it's you know, just stories,
Speaker 2: but there's certainly some extreme ability. Also, you know, people
Speaker 2: who dive really you know, prolonged diving, breathholding can develop
Speaker 2: some of these skills.
Speaker 1: Wow, it's under our control.
Speaker 2: Kind of that is under our control with training.
Speaker 1: Oh wow, fascinating. So that's where we are today. Can
Speaker 1: we hibernate humans? We're sort of at the point where
Speaker 1: we have a lot of knowledge about hibernation in some
Speaker 1: species of animals and we have to dream of making
Speaker 1: it work in humans for things like space travel. Now
Speaker 1: it's just a matter of closing that gap. We need
Speaker 1: to understand more how hibernation is triggered in animals, and
Speaker 1: we need to start testing out whether those strategies can
Speaker 1: work in people and whether our bodies can survive being
Speaker 1: at lower temperatures. As doctor Drew says, it's no matter
Speaker 1: of funding the size of it to learn more.
Speaker 2: It's really ripe for discovery, and yet it's also kind
Speaker 2: of thinking outside the box and hard to get resources
Speaker 2: to do to study. So I appreciate your program. I
Speaker 2: appreciate being able to share some of the possibilities and
Speaker 2: I hope people are interested and will support it.
Speaker 1: Yeah. Yeah, Like I said, I'm ready to invest.
Speaker 3: This idea.
Speaker 1: All right, we will have to talk, all right. We
Speaker 1: hope you enjoyed that. Thanks for joining us. I'm going
Speaker 1: to go take a nap now, but don't worry. I
Speaker 1: plan to wake up before next week's episode. See you. Then,
Speaker 1: you've been listening to Science Stuff production of iHeartRadio, written
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