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The Mysterious Aging of Astronauts

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Re: The Mysterious Aging of Astronauts

#41

Post by dbrannan »

CydeWeys wrote: post #40
bdamm wrote: post #19

Earlier quoted context omitted.

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?

The linked article does a good job of refuting this hypothesis. There are radiation workers on Earth who receive regular, higher doses than what astronauts receive, and are not subject to these effects. It really is the weightlessness doing it, not the slightly higher ambient radiation.

Would we live longer if gravity was higher than 9.81 m/s2? I think it might be difficult to actually test this, but it is a fun question.

Re: The Mysterious Aging of Astronauts

#42

Post by toomuchtodo »

CydeWeys wrote: post #40
bdamm wrote: post #19

Earlier quoted context omitted.

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?

The linked article does a good job of refuting this hypothesis. There are radiation workers on Earth who receive regular, higher doses than what astronauts receive, and are not subject to these effects. It really is the weightlessness doing it, not the slightly higher ambient radiation.

Cosmic rays have enough energy to travel through the atmosphere and damage the sight of commercial pilots. Its not a leap to think that the exposure is significantly higher in orbit.

http://news.bbc.co.uk/2/hi/health/4131232.stm

http://www.ncbi.nlm.nih.gov/pubmed/16087845

Re: The Mysterious Aging of Astronauts

#43

Post by lordnacho »

Retric wrote: post #31
nilkn wrote: post #29

Earlier quoted context omitted.

https://www.ssa.gov/oact/STATS/table4c6.html This suggests a life expectancy of ~78 years old for someone 30 years old today. Of course, as you stated, we'd really need statistics for someone who was 30 years old in the 60s. John Glenn, Neil Armstrong, Buzz Aldrin, Michael Collins and Edgar Mitchell are all at least several years beyond 78, with Glenn at an impressive 94. By the way, the life expectancy at birth in t…

https://xkcd.com/893/ 4 of the 12 people that walked on the moon have already died. If you look at the people who have not died by age X, there life expectancy is going to be based on that age. PS: As to reaching age X, http://www.businessinsider.com/social-security-life-table-ch... A 30 year old male has a ~25% chance of reaching 90. But, these sample sizes are tiny so that does not mean much.

> https://xkcd.com/893/

It's sad that they don't need a model of arrivals. I would like to at least hope that someone will walk on the moon before 2035.

Re: The Mysterious Aging of Astronauts

#44

Post by Goronmon »

dbrannan wrote: post #41
CydeWeys wrote: post #40

Earlier quoted context omitted.

The linked article does a good job of refuting this hypothesis. There are radiation workers on Earth who receive regular, higher doses than what astronauts receive, and are not subject to these effects. It really is the weightlessness doing it, not the slightly higher ambient radiation.

Would we live longer if gravity was higher than 9.81 m/s2? I think it might be difficult to actually test this, but it is a fun question.

I would assume that stronger gravity would just come along with a different set of health issues (joint and muscle problems dealing with more stress, heart would be affected having to work harder to pump blood, etc).

Re: The Mysterious Aging of Astronauts

#45

Post by derekp7 »

pcl wrote: post #39

They are also followed medically more closely than just about anyone on Earth: they don’t indulge in regular fast food I wonder what they mean by that. Are astronauts explicitly banned from eating fast food, and somehow monitored? Or are they just less likely to eat fast food, since they pay close attention to their fitness and health?

As far as I know, they haven't installed a McDonald's module on the ISS yet.

Re: The Mysterious Aging of Astronauts

#46

Post by mtdewcmu »

bdamm wrote: post #19
toomuchtodo wrote: post #15

Earlier quoted context omitted.

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?

I seem to remember from anatomy and physiology that most body cells don't really divide, the exception being epithelial cells, which are constantly being produced and shedding. So I'm not sure that DNA damage would tend to get propagated by cell division, at least in adults.

Re: The Mysterious Aging of Astronauts

#47

Post by vinceguidry »

dbrannan wrote: post #41
CydeWeys wrote: post #40

Earlier quoted context omitted.

The linked article does a good job of refuting this hypothesis. There are radiation workers on Earth who receive regular, higher doses than what astronauts receive, and are not subject to these effects. It really is the weightlessness doing it, not the slightly higher ambient radiation.

Would we live longer if gravity was higher than 9.81 m/s2? I think it might be difficult to actually test this, but it is a fun question.

If you take any complex system out of the environment it evolved to survive in, it won't work as well. Doesn't matter which knob you tweak, it won't be the environment it evolved in. There will just be a different set of failures.

Re: The Mysterious Aging of Astronauts

#48

Post by stephengoodwin »

On the reverse side, I've always wondered if being in a weightless environment makes your muscles feel great[0], since they aren't working against gravity. Over the years, gravity can create lots of problems for posture, which is why swimming (which lessen the effects of gravity) feels great.

[0] I'm using "Feel" in a relative context, since muscle weakness/wasting will not feel good once you're back in a non-weightless environment.

Re: The Mysterious Aging of Astronauts

#50

Post by ZeroFries »

vinceguidry wrote: post #47
dbrannan wrote: post #41

Earlier quoted context omitted.

Would we live longer if gravity was higher than 9.81 m/s2? I think it might be difficult to actually test this, but it is a fun question.

If you take any complex system out of the environment it evolved to survive in, it won't work as well. Doesn't matter which knob you tweak, it won't be the environment it evolved in. There will just be a different set of failures.

Is this necessarily true? I can see how it would often be true, in general, but don't see how it's necessary. For example, animals in captivity can often live longer. Lifespan and quality of life are decent enough proxies for "working well".
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