[HN Gopher] The human heart shows signs of ageing after just a m...
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The human heart shows signs of ageing after just a month in space
Author : gnabgib
Score : 106 points
Date : 2024-09-24 02:50 UTC (4 days ago)
(HTM) web link (www.nature.com)
(TXT) w3m dump (www.nature.com)
| DaoVeles wrote:
| This is no surprise. Look up how Scott Kelly described his
| experience coming back after a year on the ISS.
|
| https://www.snexplores.org/article/how-year-space-affected-s...
| vavooom wrote:
| _" The researchers tested Scott again after six months back on
| land. Roughly 91 percent of the genes that had changed activity
| in space were now back to normal. The rest stayed in space
| mode. His immune system, for instance, remained on high alert.
| DNA-repair genes were still overly active and some of his
| chromosomes were still topsy-turvy. What's more, Scott's mental
| abilities had declined from preflight levels. He was slower and
| less accurate on short-term memory and logic tests."_
| tirant wrote:
| What that study does not take into account is that Scott was
| traveling around the world for 6 months giving interviews. I
| would have also expected a decline in that context.
|
| Also his mental abilities recovered back to baseline some
| time after.
| datameta wrote:
| I need to look through the study more, but what was done to
| control for the isolation that a year on the ISS brings?
| suprjami wrote:
| I don't think that's a factor. The ISS is anything but
| lonely. Astronauts have internet up there and are regularly
| in touch with their family. I think it's also reasonable to
| say they know what they're getting into when they go up, so
| physical separation is unlikely to affect astronauts as
| badly as the general population. Many of these people are
| ex-military and have regularly been on long deployments
| away from home.
| wileydragonfly wrote:
| Permanently screws up your vision, too
| tomwiddles wrote:
| In what way? This is news to me
| selectodude wrote:
| https://today.tamu.edu/2021/01/15/how-does-long-term-
| spacefl...
| wileydragonfly wrote:
| Body is evolved to have fluid under pressure to resist
| gravity. You get rid of gravity and we aren't built for it. I
| was peripherally involved in a research study where they were
| going to strap people to beds for three months with their
| heads below their torsos. Every so often they would be
| wheeled into a centrifuge to see if it would counter act the
| damage. It's so risky you can't do it in America so we had to
| use human subjects in Germany which was... on brand.
| arandomusername wrote:
| would love to read more on this. Do you have a link to the
| study by any chance?
| georgeburdell wrote:
| I wonder if it's temporary, like a woman during pregnancy
|
| https://www.washingtonpost.com/wellness/2024/04/08/pregnancy...
| rafram wrote:
| Absolutely insane and cool that it's possible to grow part of a
| heart in a lab, put it on a dish, blast it off into space, and
| study its behavior. So much in our modern world would've been a
| sci-fi dream only a few decades ago.
| Andrex wrote:
| I wonder if there will ever be a legalized market for synthetic
| human meat.
| owenpalmer wrote:
| Meat for eating? Hopefully not. Meat for organ and tissue
| replacement? Hopefully so.
| Hammershaft wrote:
| Why hopefully not? As long as it's safe I don't see any
| ethical grounds for criminalization. Lab grown meats might
| open the door to all kinds of chimeric meats flavors we
| can't even dream of right now, all without animal
| suffering, deforestation, or the ingestion of
| bioaccumulated toxins.
| __MatrixMan__ wrote:
| It would be a little unsettling to run across somebody
| who was successfully creating foods which resembled meat
| who had chosen "resembles human" as the direction that
| they'd like to pursue.
| TeMPOraL wrote:
| If there's a demand (or it can be induced), it's called
| "entrepreneurship".
| ben_w wrote:
| Only when everyone else isn't so disgusted by the idea
| that they dismiss it out of hand.
|
| I could give four examples that are already available
| synthetically but not acceptable to payment processors
| due to widespread disgust, but I suspect it's unwise to
| knowingly suggest here things that trigger most people's
| disgust reflexes.
| iwontberude wrote:
| Hey I stick to organic payment processors, like maple
| syrup. Decent inflation, can be prone to blight or other
| natural disaster but none of that synthetic stuff.
| ben_w wrote:
| Great, but I have yet to meet a landlord which accepts
| maple syrup as rent for the space in which to put a
| commercial food-grade bioreactor lab.
| Zigurd wrote:
| > Only when everyone else isn't so disgusted by the
| idea...
|
| BNPL? Worldcoin? Flow? Juul?
| teddyh wrote:
| <https://angryflower.com/602.html>
| Hammershaft wrote:
| Imagine! You could upload a genetic sample and order a
| tenderloin of yourself!
| Zigurd wrote:
| The Kardashians will license their DNA under the brand _Eat
| the Rich_.
| jajko wrote:
| Now who would eat that garbage junk food, I hope people
| have higher moral standards... oh wait
| amelius wrote:
| Probably a bad idea. Research tells us that prion diseases
| existed more among cannibal groups.
| jajko wrote:
| Aren't prions nerve cells + something something? Muscle
| cells are not that different from muscle cells of animals
| we eat regularly.
| wizzwizz4 wrote:
| Prions are misfolded proteins that act as enzymes to turn
| healthy proteins into more of themselves. The scary ones
| destroy the nervous system, but that's not an inherent
| part of being a prion.
| JumpCrisscross wrote:
| > _prion diseases existed more among cannibal groups_
|
| Presumably one would exclude protein classes prone to
| prionic misfolding from the synthetic meat. Personally, I
| have no moral qualms with someone sampling lab-grown human
| flesh, though I'd probably pass.
| qwertox wrote:
| Huge market for influencers. "Be like me."
| layer8 wrote:
| It's "just" a few millimetres of tissue attached ("glued") on a
| chip:
| https://www.nature.com/articles/s41598-020-76062-w/figures/2
| JoeAltmaier wrote:
| The health hazards of space may be entirely treatable or
| preventable, with enough research. By no means in the human body
| any kind of barrier to exploring space!
|
| There have been so very few space denizens, the science is in its
| infancy.
|
| Space travel itself could be changed. For instance, a rocket to
| Mars may swing the habitat in a circle at the end of a miles-long
| wire to create artificial gravity. To those that claim
| 'acceleration is different from gravity', take your physics
| course again.
|
| And people can be changed. It took a special kind of person to
| live at high altitude, and on an island with periodic feast-and-
| famine, and on a 2000 calorie rice diet, and in a crowded city,
| and on a submarine.
|
| We can imagine (and often have in science fiction) a person built
| to crew long space missions. And we can imagine space missions
| designed for humans. Right now it's all in early days.
| tptacek wrote:
| By a lot of means is the human body a kind of barrier to
| exploring space, so many and with such intensity as to call
| into question the whole exercise. Maybe it'll all work out, but
| it seems unreasonable to literally dismiss the question.
| AStonesThrow wrote:
| All we need to do is compare the extent to which Man has
| explored space (and oceans and volcanoes etc.) vs. the extent
| that robots have been sent on our behalf, with quite
| resounding success, and the barriers are self-evident.
|
| Not to mention the liability and really bad P.R. when human
| lives are lost in that pursuit.
| SoftTalker wrote:
| I think it's unlikely. Humans (and all other life on Earth)
| evolved to live on Earth. I think it's very doubtful that
| humans can live long-term anywhere else.
| hombre_fatal wrote:
| It's just a technology problem.
| JoeAltmaier wrote:
| That supposition is not altogether clear - seeds of life
| may have been asteroid/meteorite provided, in which case
| life on earth was evolved for different places entirely.
|
| Anyway, the Cambrian explosion shows how life can fill any
| ecological niche from ocean-bottom sulfur vents to
| mountaintops, from the stratosphere to mudpots in
| Yellowstone.
|
| We don't have to wait for that. Lots of science fiction
| about making people to fit the world. An obvious solution,
| and already we're gaining the tools to do it.
| kibwen wrote:
| Sure, but once you engineer a creature capable of living
| in 0g, it seems likely that the biological difference
| will be great enough that we'll be calling it something
| other than "human". And it almost certainly won't be
| capable of living on Earth without life support.
| JoeAltmaier wrote:
| Eyesight issues? Bone issues? Null-gravity related. Solutions
| are clear there, and not even hard
|
| Radiation, that one is difficult. Water barrier? Magentic
| bottle? harder.
|
| What other issues? The 'submarine' one has been largely
| solved, for, you know, submarine crews.
| tptacek wrote:
| It seems you take my point. :)
| JoeAltmaier wrote:
| And I presume you take mine - that smarter people than us
| will be highly motivated to solve the problem. :)
| tptacek wrote:
| I don't agree, but past "this is a question worth taking
| seriously" I don't feel committed to litigating it;
| reasonable people can disagree!
| pdonis wrote:
| _> create artificial gravity. To those that claim
| 'acceleration is different from gravity', take your physics
| course again._
|
| The physics course, at least if it includes General Relativity,
| will tell you that what the human body is used to is not
| gravity but acceleration. The astronauts in free fall in the
| ISS are fully responding to Earth's gravity; the difference
| between them and the rest of us stuck here on the Earth's
| surface is that we are feeling acceleration, because the
| Earth's surface is pushing upward on us, and they are not.
|
| The potential issue with having a spaceship habitat swinging in
| a circle to create acceleration is the Coriolis effect; that
| would make it feel at least somewhat different from being on
| the Earth's surface, even if the magnitude of the acceleration
| were 1 g. That might cause something like motion sickness in
| some people--but then again, so does free fall. (I myself don't
| even like roller coasters, so I would probably be a very poor
| candidate for being a free-fall astronaut.)
| nine_k wrote:
| AFAICT, the equivalence of gravitational and inertial masses
| is not a completely solved problem in modern physics.
|
| Earth also rotates, and thus the Coriolis effect is present.
| It's not as noticeable as in a fast-rotating habitat in
| space, but air navigation, naval navigation, and artillery
| all make adjustments for it, among other factors, especially
| at high latitudes.
| pdonis wrote:
| >* the equivalence of gravitational and inertial masses is
| not a completely solved problem in modern physics.*
|
| I'm not sure what you mean. In GR the two are equivalent,
| period. There is no open issue there.
|
| _> Earth also rotates, and thus the Coriolis effect is
| present._
|
| Yes, but on the scale of a human it is far, far too tiny to
| be detectable. So it doesn't make a difference to what
| humans experience on Earth, even though, as you note, there
| are scenarios in which it has to be taken into account.
|
| In a space habitat swinging around to provide artificial
| acceleration, however, I think the Coriolis effect on a
| human would be large enough to be detectable by the human.
| At least unless you made the length of the cable it was
| swinging on of the same order as the radius of the Earth,
| i.e., thousands of kilometers, which is not likely to be
| practical.
| nine_k wrote:
| In GR, the equivalence of inertial and gravitational
| masses is _assumed_ , not proven in any way [1]. GR, of
| course, holds exceptionally well during the last 100+
| years of experiments.
|
| Indeed, in a small enough rotating habitat, jumping
| straight up would reveal the direction of rotation, and
| jumping "forward" and "backward" would have noticeably
| different results.
|
| There's hoping though that the mechanisms which under
| zero g make the bones lose calcium, make tissues with a
| lot of small blood vessels swell, etc, won't be as
| seriously affected by the small variations introduced by
| the Coriolis effect as they are affected by the lack of
| weight and the pressure resulting from the weight.
| Solving 100.00% of a problem would be wonderful, but
| solving roughly 90% would already be highly beneficial.
|
| [1]: https://en.wikipedia.org/wiki/Equivalence_principle#
| Einstein...
| fouc wrote:
| There is a gravity gradient in the centrifuge, for a 2m tall
| person, if the radius is only 10m, gravity gradient ranges
| from 20% to 100% from head to toe, meaning it's quite
| noticeable. But at 100m radius it's only 2%, and presumed to
| not be noticeable (I'm not sure if they've actually put that
| to the test).
|
| https://ntrs.nasa.gov/api/citations/20070001008/downloads/20.
| ..
| pdonis wrote:
| _> a gravity gradient_
|
| More precisely an acceleration gradient, at least in the
| terminology I was using in my previous post. Yes, this is a
| good point.
| JoeAltmaier wrote:
| So use a 1km tether. Lots of room in space.
| jajko wrote:
| You are mixing few different things here - yes AFAIK sherpas /
| tibetans have genes preselected to cope better with altitude,
| but there is absolutely 0 zilch nothing of such about 'crowded
| city or a submarine'.
|
| WTF would that actually even be, submarines have cca surface
| pressure, maybe you meant adaptation to generally shitty
| soulless draining more stresful environments? Again, nothing
| like that out there in gene pool, city folks generally love
| running away to the nature as much as they can, at least those
| who already experienced how healing and recharging it can be
| and can afford it.
| JoeAltmaier wrote:
| Yet they screen successfully for submariners and get a good
| crew. Their genes came from somewhere.
|
| And every human in existence has been adapted over the last
| 50K years for tribal, village and city conditions. Early
| hominids were very different - hairier, loners, more
| fractious, used more calories, communicated less.
|
| AMH (anatomically modern humans) have co-evolved with crowded
| conditions, to live in groups and tolerate each other without
| killing one another. So maybe three modifiers on that was
| hyperbole.
| c420 wrote:
| >And every human in existence has been adapted over the
| last 50K years
|
| 50k years is a blink in the context of evolution. You're
| looking exclusively at cultural adaptations in this
| timeframe.
| jwells89 wrote:
| Yes, there's clearly hurdles on the path but I think they're
| well worth figuring out how to clear.
|
| There's multiple reasons why but one that stands out in my mind
| is the sheer difference in trajectories between a species that
| embraces spacefaring and comes to live on multiple worlds
| compared to a species that remains confined to its point of
| origin. In the long term, the former of those two will
| eventually fan out to other star systems and explore countless
| more modes of existence, structuring of societies, ways of
| expression, avenues of science, etc than the latter can ever
| hope to. Staying put stymies potential to an extent that's
| difficult to even comprehend.
| pvaldes wrote:
| Substitute "human heart" by "a culture of isolated cells of human
| heart growing on a petri dish". Not the same thing.
| Aldipower wrote:
| Does it aged just one month?
| dan-robertson wrote:
| Perhaps we could learn more about space if we diverted a bit more
| money towards telescopes and probes and rovers and suchlike, and
| a little less money towards figuring out life-support for
| primates in LEO. But then I write this as someone who's taxes do
| not go towards NASA, nor indeed towards any notable space
| exploration.
| RecycledEle wrote:
| I had hoped Robert Heinlein's hypothesis (in his fiction books)
| about zero-G lessening the demands on the hyman body and
| therefore increasing out lifespans would pan out.
|
| Maybe science will come up with something.
| wongarsu wrote:
| If the simple version of that hypothesis is true, then why is
| exercise so beneficial? Even in 1g our lifespan suffers if we
| don't regularly stress our body.
|
| Maybe in 0g it is possible to find a better balance with lower
| baseline stress, with regular high-stress periods. But any
| ideas on how to even reach earth-equivalent levels of
| healthiness require much better space stations than what we
| have or build today
| devmor wrote:
| The problem with that idea is that the human body exists via
| evolutionary fitness for gravitational stress.
|
| Imagine a mechanical arm whose purpose is to put constant
| hydraulic pressure against a platform that is putting pressure
| towards the arm. Now imagine what happens when you take away
| the platform - the arm would likely damage itself unless
| specifically designed to handle the lack of pressure.
| KasianFranks wrote:
| Yep, Scott Kelly, after a year in space, lost about 30% of his
| hearts muscle mass. Ref: https://www.nasa.gov/humans-in-
| space/nasas-twins-study-resul...
| lifeinthevoid wrote:
| Next to all the other difficult problems to solve when sending
| people to Mars, this one looks particularly nasty.
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