9 ms·

Why We Age

94 points by Mitchhhs 11y ago

reasonattlm 11y ago
You might also see the great short introduction to the conservative scientific view on aging here: http://senescence.info/aging_theories.html http://senescence.info/aging_theories.html You'll also find a good introduction to the modern "aging is damage" viewpoint in the SENS distillation of consensus positions from various per-disease research fields: http://sens.org/research/introduction-to-sens-research http://sens.org/research/introduction-to-sens-research That is one synthesis of which damage is primary and important. Another is the Hallmarks of Aging: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3836174/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3836174/
markbnj 11y ago
I find the life expectancy vs. heart rate graph very interesting. The human point is the only one that lies well off the line of correlation, and it's tempting to see the distance as a result of our technological achievements. In other words, we're the only animal to have pushed ourselves to the right of that line by being able to fix at least some of what goes wrong.
- Namrog84 11y ago
  I wonder how much a lower resting heart rate average over a lifespan influences average life expectancy. Is it enough for us to consider lower heart rate as an ideal value to optimize? Obviously being in better shape and see often correlated.
  - reasonattlm 11y ago
    Rate of living theories are somewhat discredited. http://en.wikipedia.org/wiki/Rate_of_living_theory http://en.wikipedia.org/wiki/Rate_of_living_theory There is some question over correlation of resting metabolic rate and mitochondrial constituents as a correlation of species life span, but that is totally separate from considerations of variations in life span within a species. http://dx.doi.org/10.1089/rej.2008.0676 http://dx.doi.org/10.1089/rej.2008.0676 Nonetheless, resting metabolic rate does seem to predict human longevity: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3100751/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3100751/ Interestingly the Palo Alto Longevity Prize is using heart rate variability as a metric to optimize in mammals: http://paloaltoprize.com/ http://paloaltoprize.com/
- guard-of-terra 11y ago
  I'm sure there are other exceptions, they're just not shown. Humans are atypical, but so are sloths.
- Qantourisc 11y ago
  There is another theory about this: older humans are not 100% useless, they provide wisdom and skills to the younger people. As such communities with (not a burden) elder people have an advantage. And this removes some of the selection shadow.
  - kaybe 11y ago
    Humans are not the only species for which this is true though.
- abecedarius 11y ago
  Those graphs show only mammals. IIRC some birds would be about as far off the mammalian line of best fit.
farresito 11y ago
The more I read about aging, the more interested I become about the subject, especially after Google created Calico and after watching some talks by Aubrey de Grey. Reversing aging seems like such a science fiction thing, but then you take a look at how things were 50 years ago and how things are right now and you realize that a lot of the things that seem impossible right now might very well be possible in 20, 30 or 50 years.
- reasonattlm 11y ago
  We are living in the midst of the early phases of a biotechnology revolution every bit as profound and transformative as the computing revolution from the 1970s on. It is less apparent than it might be to the average person in the street because (a) next to no-one really spends much time thinking about medical research unless they have to, which is a whole massive issue with our society in and of itself, (b) regulatory burdens on medical technology ensures that the clinic is 10-20 years behind the bounds of the possible in the labs. Medical tourism does its part to help keep that delay lower than it might, but it's still a huge burden, and a huge cost in life - especially now that the upward curve of progress is potentially so steep. The potential to be able to treat aging and begin to bring it under medical control within the next 20 years - IF the right research fields begin to dominate the mainstream, IF the funding arises, IF the public wakes up and regards aging research in the same was as they regard cancer research - is very real. That is why people like me spend time and effort to bang the drum, conduct grassroots fundraisers, and support progress in SENS-like rejuvenation research focused on repair of the cellular and tissue damage thought to cause aging. For example, clearance of senescent cells, an approach which has just now reached the point of credible demonstrations in normal mice, but needs much more support to make it into the mainstream. Is Calico funding this? No, not yet, and they won't until it gets more support: http://www.scripps.edu/news/press/2015/20150309agingcell.html http://www.scripps.edu/news/press/2015/20150309agingcell.htm... Advocates and the research community are making progress, great progress when you look at 2015 in comparison to the state of things in 2005, but we need more people to take the step, become philanthropists, and materially support this and other early-stage research with the aim of bringing medicine under medical control. That support really does make a difference.
ExpiredLink 11y ago
> If you think about it, nearly all things age. Your car. Wine. Cheese. The electronic device you’re reading this on. Actually, no. Those things don't 'age' like you age. BTW, trying to answer existentialist questions with biological theories is futile.
- guard-of-terra 11y ago
  Existentialist questions can't be solved with existentialism but might well be solved by other realms of knowledge. You could not answer the question "why does plague decimates us", until you could answer "it does not" and the question left the horizon.
- reasonattlm 11y ago
  Actually, they do age like you age, obviously so for the car and the device where it is a matter of breakage of components, and for the wine and the cheese more a matter of drawing analogies with specific biochemical processes involved in aging. Reliability theory applies very well to aging, just as it does to the aging of machinery, and its high level models reproduce reality quite well: http://en.wikipedia.org/wiki/Reliability_theory http://en.wikipedia.org/wiki/Reliability_theory http://en.wikipedia.org/wiki/Reliability_theory_of_aging_and_longevity http://en.wikipedia.org/wiki/Reliability_theory_of_aging_and...
- deleted 11y ago
  [deleted]
- Florin_Andrei 11y ago
  At the bottom, it's all an increase in entropy. That's my standard answer, probably informed by my college studies (Physics, not CS). The layers on top might be different, but at the very bottom of things, it's always entropy "trying" to increase. That's why computers eventually break, that's why living things age and die. To counteract this tendency, you'd have to somehow prevent the entropic increase within each system. Technically doable, but the devil is in the details. Life itself fights entropy, the problem is that whatever anti-entropic mechanisms it employs, they're not stable long-term, at least not for pluricellular organisms as separate systems. The biosphere as a whole has actually been remarkably resilient so far.
evo_9 11y ago
Interesting and thorough article, very good read. I've posted about some of the interesting stuff going on regarding stem cells, particularly around hockey legend Gordie Howe's rather miraculous recover from a stroke earlier this year. I'm really not sure why this isn't getting more news nationally, or even why on HN it isn't getting any traction/discussion: http://www.freep.com/story/sports/nhl/red-wings/2015/05/18/gordie-howe-stem-cells-detroit/27536175/ http://www.freep.com/story/sports/nhl/red-wings/2015/05/18/g...
- mrfusion 11y ago
  https://news.ycombinator.com/item?id=9566335 https://news.ycombinator.com/item?id=9566335
  - evo_9 11y ago
    That's my original post yesterday for this story. No discussion or interest/upvote. So is it simply that the average HN'er is around 28 years old and just doesn't care about aging or stem cell research that is mostly aimed at fixing 'old people'? Is everyone just assuming this stuff will get sorted out in the next 20 years by time the average HN'er actually needs to worry about it? Or is it because the stem cell medical centers that provided Mr. Howe with the treatments are outside the US? Aka, not invented here so must be BS? It's puzzling, I mean we all have parents that are aging and having gone through watching a parent lose a lot of their capabilities from a stroke last year (and eventually dying from the strokes fallout a few months later), all I can say is this stuff can become front and center to your personal interest very rapidly when it hits home.
    - bootload 11y ago
      "That's my original post yesterday for this story. No discussion or interest/upvote." The surface area of HN is so broad, the number of readers interested in pretty low. This is a observable problem. I often see lots of votes and zero responses for interesting posts. Interesting enough to click, glance over, but not enough to think about and comment.
jostmey 11y ago
I love this article! The author points out that as lifespan goes up the effect of aging on fitness goes down. So provided that an organism lives long enough, aging is not penalized by Natural Selection.
shenanigoat 11y ago
This article was very well presented, clear, and informative. Thank you. I look forward to your next one(s).
the_kingsley 11y ago
It would be great to stay young. I'm happy to report that scientists have been seriously testing if stuff actually works for over a century (Slonaker, 1912). They typically try an intervention, like diet or exercise, on lab animals, and then see how long they live. For what it's worth, I maintain the world's biggest spread sheet of these life span experiments. It summarizes over 14,000. One column is the intervention (diet, exercise, etc..) another is the change in lifespan (+10%, -2%, etc...) another is the species (human, mice, etc...) and so on. It's interesting to see what works. More info is at http://morse.kiwi.nz/kingsley/doku.php?id=science:start http://morse.kiwi.nz/kingsley/doku.php?id=science:start
- gavazzy 11y ago
  You want $1,000,000 to get the report of life span experiments?
  - themartorana 11y ago
    Also he has stripped electromagnetic waves to just get magnetic waves and he doesn't know about man-made climate change because of correlations.
    - gavazzy 11y ago
      Whoa, he should submit his results to Nature!
pseud0r 11y ago
For anyone interested in why we age and what research needs to be done to cure it, I'd recommend this article http://protein.bio.msu.ru/biokhimiya/contents/v78/pdf/bcm_1061.pdf http://protein.bio.msu.ru/biokhimiya/contents/v78/pdf/bcm_10... The most interesting part is that a relatively simple medical procedure called plasmapheresis or plasma exchange, might be used for rejuvenation. The process would be to exchange the blood plasma of an old person with that of a young person many times over a period of time. The blood plasma contains signaling molecules and there is strong evidence that some of them are used to synchronize the current age throughout the body, perhaps to a master clock somewhere. This causes telomeres to be shortened, DNA repair mechanisms to be turned off, stem cells to stop dividing etc. If the clock could be reset with young plasma, the stem cells would be reset to a young state and can start dividing again to regenerate tissue. Experiments on rats suggests this is indeed happening and a number of academic labs and even a startup called alkahest is now working on getting this tested in humans.

94 points by Mitchhhs 11y ago

You might also see the great short introduction to the conservative scientific view on aging here: http://senescence.info/aging_theories.html http://senescence.info/aging_theories.html You'll also find a good introduction to the modern "aging is damage" viewpoint in the SENS distillation of consensus positions from various per-disease research fields: http://sens.org/research/introduction-to-sens-research http://sens.org/research/introduction-to-sens-research That is one synthesis of which damage is primary and important. Another is the Hallmarks of Aging: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3836174/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3836174/

markbnj 11y ago

I find the life expectancy vs. heart rate graph very interesting. The human point is the only one that lies well off the line of correlation, and it's tempting to see the distance as a result of our technological achievements. In other words, we're the only animal to have pushed ourselves to the right of that line by being able to fix at least some of what goes wrong.

Namrog84 11y ago
I wonder how much a lower resting heart rate average over a lifespan influences average life expectancy. Is it enough for us to consider lower heart rate as an ideal value to optimize? Obviously being in better shape and see often correlated.
- reasonattlm 11y ago
  Rate of living theories are somewhat discredited. http://en.wikipedia.org/wiki/Rate_of_living_theory http://en.wikipedia.org/wiki/Rate_of_living_theory There is some question over correlation of resting metabolic rate and mitochondrial constituents as a correlation of species life span, but that is totally separate from considerations of variations in life span within a species. http://dx.doi.org/10.1089/rej.2008.0676 http://dx.doi.org/10.1089/rej.2008.0676 Nonetheless, resting metabolic rate does seem to predict human longevity: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3100751/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3100751/ Interestingly the Palo Alto Longevity Prize is using heart rate variability as a metric to optimize in mammals: http://paloaltoprize.com/ http://paloaltoprize.com/
guard-of-terra 11y ago
I'm sure there are other exceptions, they're just not shown. Humans are atypical, but so are sloths.
Qantourisc 11y ago
There is another theory about this: older humans are not 100% useless, they provide wisdom and skills to the younger people. As such communities with (not a burden) elder people have an advantage. And this removes some of the selection shadow.
- kaybe 11y ago
  Humans are not the only species for which this is true though.
abecedarius 11y ago
Those graphs show only mammals. IIRC some birds would be about as far off the mammalian line of best fit.

farresito 11y ago

The more I read about aging, the more interested I become about the subject, especially after Google created Calico and after watching some talks by Aubrey de Grey. Reversing aging seems like such a science fiction thing, but then you take a look at how things were 50 years ago and how things are right now and you realize that a lot of the things that seem impossible right now might very well be possible in 20, 30 or 50 years.

reasonattlm 11y ago
We are living in the midst of the early phases of a biotechnology revolution every bit as profound and transformative as the computing revolution from the 1970s on. It is less apparent than it might be to the average person in the street because (a) next to no-one really spends much time thinking about medical research unless they have to, which is a whole massive issue with our society in and of itself, (b) regulatory burdens on medical technology ensures that the clinic is 10-20 years behind the bounds of the possible in the labs. Medical tourism does its part to help keep that delay lower than it might, but it's still a huge burden, and a huge cost in life - especially now that the upward curve of progress is potentially so steep. The potential to be able to treat aging and begin to bring it under medical control within the next 20 years - IF the right research fields begin to dominate the mainstream, IF the funding arises, IF the public wakes up and regards aging research in the same was as they regard cancer research - is very real. That is why people like me spend time and effort to bang the drum, conduct grassroots fundraisers, and support progress in SENS-like rejuvenation research focused on repair of the cellular and tissue damage thought to cause aging. For example, clearance of senescent cells, an approach which has just now reached the point of credible demonstrations in normal mice, but needs much more support to make it into the mainstream. Is Calico funding this? No, not yet, and they won't until it gets more support: http://www.scripps.edu/news/press/2015/20150309agingcell.html http://www.scripps.edu/news/press/2015/20150309agingcell.htm... Advocates and the research community are making progress, great progress when you look at 2015 in comparison to the state of things in 2005, but we need more people to take the step, become philanthropists, and materially support this and other early-stage research with the aim of bringing medicine under medical control. That support really does make a difference.

ExpiredLink 11y ago

> If you think about it, nearly all things age. Your car. Wine. Cheese. The electronic device you’re reading this on. Actually, no. Those things don't 'age' like you age. BTW, trying to answer existentialist questions with biological theories is futile.

guard-of-terra 11y ago
Existentialist questions can't be solved with existentialism but might well be solved by other realms of knowledge. You could not answer the question "why does plague decimates us", until you could answer "it does not" and the question left the horizon.
reasonattlm 11y ago
Actually, they do age like you age, obviously so for the car and the device where it is a matter of breakage of components, and for the wine and the cheese more a matter of drawing analogies with specific biochemical processes involved in aging. Reliability theory applies very well to aging, just as it does to the aging of machinery, and its high level models reproduce reality quite well: http://en.wikipedia.org/wiki/Reliability_theory http://en.wikipedia.org/wiki/Reliability_theory http://en.wikipedia.org/wiki/Reliability_theory_of_aging_and_longevity http://en.wikipedia.org/wiki/Reliability_theory_of_aging_and...
deleted 11y ago
[deleted]
Florin_Andrei 11y ago
At the bottom, it's all an increase in entropy. That's my standard answer, probably informed by my college studies (Physics, not CS). The layers on top might be different, but at the very bottom of things, it's always entropy "trying" to increase. That's why computers eventually break, that's why living things age and die. To counteract this tendency, you'd have to somehow prevent the entropic increase within each system. Technically doable, but the devil is in the details. Life itself fights entropy, the problem is that whatever anti-entropic mechanisms it employs, they're not stable long-term, at least not for pluricellular organisms as separate systems. The biosphere as a whole has actually been remarkably resilient so far.

evo_9 11y ago

Interesting and thorough article, very good read. I've posted about some of the interesting stuff going on regarding stem cells, particularly around hockey legend Gordie Howe's rather miraculous recover from a stroke earlier this year. I'm really not sure why this isn't getting more news nationally, or even why on HN it isn't getting any traction/discussion: http://www.freep.com/story/sports/nhl/red-wings/2015/05/18/gordie-howe-stem-cells-detroit/27536175/ http://www.freep.com/story/sports/nhl/red-wings/2015/05/18/g...

mrfusion 11y ago
https://news.ycombinator.com/item?id=9566335 https://news.ycombinator.com/item?id=9566335
- evo_9 11y ago
  That's my original post yesterday for this story. No discussion or interest/upvote. So is it simply that the average HN'er is around 28 years old and just doesn't care about aging or stem cell research that is mostly aimed at fixing 'old people'? Is everyone just assuming this stuff will get sorted out in the next 20 years by time the average HN'er actually needs to worry about it? Or is it because the stem cell medical centers that provided Mr. Howe with the treatments are outside the US? Aka, not invented here so must be BS? It's puzzling, I mean we all have parents that are aging and having gone through watching a parent lose a lot of their capabilities from a stroke last year (and eventually dying from the strokes fallout a few months later), all I can say is this stuff can become front and center to your personal interest very rapidly when it hits home.
  - bootload 11y ago
    "That's my original post yesterday for this story. No discussion or interest/upvote." The surface area of HN is so broad, the number of readers interested in pretty low. This is a observable problem. I often see lots of votes and zero responses for interesting posts. Interesting enough to click, glance over, but not enough to think about and comment.

jostmey 11y ago

I love this article! The author points out that as lifespan goes up the effect of aging on fitness goes down. So provided that an organism lives long enough, aging is not penalized by Natural Selection.

shenanigoat 11y ago

This article was very well presented, clear, and informative. Thank you. I look forward to your next one(s).

the_kingsley 11y ago

It would be great to stay young. I'm happy to report that scientists have been seriously testing if stuff actually works for over a century (Slonaker, 1912). They typically try an intervention, like diet or exercise, on lab animals, and then see how long they live. For what it's worth, I maintain the world's biggest spread sheet of these life span experiments. It summarizes over 14,000. One column is the intervention (diet, exercise, etc..) another is the change in lifespan (+10%, -2%, etc...) another is the species (human, mice, etc...) and so on. It's interesting to see what works. More info is at http://morse.kiwi.nz/kingsley/doku.php?id=science:start http://morse.kiwi.nz/kingsley/doku.php?id=science:start

gavazzy 11y ago
You want $1,000,000 to get the report of life span experiments?
- themartorana 11y ago
  Also he has stripped electromagnetic waves to just get magnetic waves and he doesn't know about man-made climate change because of correlations.
  - gavazzy 11y ago
    Whoa, he should submit his results to Nature!

pseud0r 11y ago

For anyone interested in why we age and what research needs to be done to cure it, I'd recommend this article http://protein.bio.msu.ru/biokhimiya/contents/v78/pdf/bcm_1061.pdf http://protein.bio.msu.ru/biokhimiya/contents/v78/pdf/bcm_10... The most interesting part is that a relatively simple medical procedure called plasmapheresis or plasma exchange, might be used for rejuvenation. The process would be to exchange the blood plasma of an old person with that of a young person many times over a period of time. The blood plasma contains signaling molecules and there is strong evidence that some of them are used to synchronize the current age throughout the body, perhaps to a master clock somewhere. This causes telomeres to be shortened, DNA repair mechanisms to be turned off, stem cells to stop dividing etc. If the clock could be reset with young plasma, the stem cells would be reset to a young state and can start dividing again to regenerate tissue. Experiments on rats suggests this is indeed happening and a number of academic labs and even a startup called alkahest is now working on getting this tested in humans.