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The Mysterious Aging of Astronauts

lemire.me

11–20 of 61 posts

Re: The Mysterious Aging of Astronauts

#12
Maybe there's a diet-related problem? Astronaut food has some pretty intense constraints that Earth food doesn't, and has almost certainly been optimized according to the false discoveries of the field of nutrition. They should have a few people with different contrarian positions look over the food logs, and see if there's anything really wrong there.

Re: The Mysterious Aging of Astronauts

#13

Is there a citation for the following claim? I've never heard of such a thing: "But then more results started coming back. Not only do astronauts come back with weak muscles and frail bones… But they also suffer from skin thinning, atherosclerosis (stiffer arteries), resistance to insulin and they suffer from loss of vision due to cataracts many years earlier than expected given their chronological age. These symptom…

There's a slew of references ("further reading") listed at the bottom, some of them look like they are the source of at least some of these claims.

Re: The Mysterious Aging of Astronauts

#14

Is there a citation for the following claim? I've never heard of such a thing: "But then more results started coming back. Not only do astronauts come back with weak muscles and frail bones… But they also suffer from skin thinning, atherosclerosis (stiffer arteries), resistance to insulin and they suffer from loss of vision due to cataracts many years earlier than expected given their chronological age. These symptom…

In addition to the references in the article, Wikipedia (surprisingly) has a nice article on the effects of spaceflight on the human body (with all sorts of references): https://en.wikipedia.org/wiki/Effect_of_spaceflight_on_the_h...

Re: The Mysterious Aging of Astronauts

#15

Is there a citation for the following claim? I've never heard of such a thing: "But then more results started coming back. Not only do astronauts come back with weak muscles and frail bones… But they also suffer from skin thinning, atherosclerosis (stiffer arteries), resistance to insulin and they suffer from loss of vision due to cataracts many years earlier than expected given their chronological age. These symptom…

They're not aging at an accelerated rate, they're exhibiting similar symptoms of aging from their microgravity environment (weak muscles, frail bones) and from there being no shielding from cosmic rays (cataracts).

Re: The Mysterious Aging of Astronauts

#16

Is there a citation for the following claim? I've never heard of such a thing: "But then more results started coming back. Not only do astronauts come back with weak muscles and frail bones… But they also suffer from skin thinning, atherosclerosis (stiffer arteries), resistance to insulin and they suffer from loss of vision due to cataracts many years earlier than expected given their chronological age. These symptom…

In addition to the references in the article, Wikipedia (surprisingly) has a nice article on the effects of spaceflight on the human body (with all sorts of references): https://en.wikipedia.org/wiki/Effect_of_spaceflight_on_the_h...

Looks like my mistake was in thinking that the stated effects were occurring after astronauts had returned to Earth. At least that's what the title sounds like. If these symptoms only apply to humans while they are in a weightless environment then it sounds very much like sedentary disease (aka sitting disease). Even rigorous exercise routines can't fully match the effects of gravity on the human body.

Re: The Mysterious Aging of Astronauts

#18
post #8

[deleted]

That's a nice theory, but I'm going to call [citation needed] anyway. Can you cite any explanations of how weightlessness would cause something like cataracts or insulin resistance, or even of whether there's a statistically significant correlation focusing on the single variable of weightlessness vs. others that might be involved?

The symptoms match health effects caused by a sedentary lifestyle: https://en.wikipedia.org/wiki/Sedentary_lifestyle#Health_eff... . In a gravitational environment, just moving around is a form of exercise since one has to move about the entire weight of one's body. In space, where everything is weightless, it takes much less effort to move around and you see the same effects (even with rigorous exercise routines). Imagine exercising for an hour or two and then sitting down for the other 22 hours. You'd end up with similar health effects.

Re: The Mysterious Aging of Astronauts

#19

Is there a citation for the following claim? I've never heard of such a thing: "But then more results started coming back. Not only do astronauts come back with weak muscles and frail bones… But they also suffer from skin thinning, atherosclerosis (stiffer arteries), resistance to insulin and they suffer from loss of vision due to cataracts many years earlier than expected given their chronological age. These symptom…

They're not aging at an accelerated rate, they're exhibiting similar symptoms of aging from their microgravity environment (weak muscles, frail bones) and from there being no shielding from cosmic rays (cataracts).

Perhaps we could conclude that cosmic rays cause increased rate of aging. Actually, it seems pretty obvious really, that a body healing itself from radiation damage would "age" more quickly. Doesn't every cell division increase the cost of further cell divisions through mutations? And isn't there actually a mechanism to ultimately shut down cell division i.e. Telomere breakdown?

Re: The Mysterious Aging of Astronauts

#20
post #4

This is interesting. You feel gravity less when you are in fluids. Does this mean all babies feel gravity differently because we all experience different amounts of fluid in the womb (not to mention the variations in baby sizes)? The impact is probably miniscule but I wonder if it has any effect on development of babies in the womb.

I guess you feel it less only because the support (pressure) is distributed more evenly along your skin. Inside your body, almost everything is fluid, so there it does not matter much, I'd say.
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