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Reddit user explains aging vs cancer

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Re: Reddit user explains aging vs cancer

#11

Post by michaelpinto »

rsheridan6 wrote: post #3

If this idea is true, people who appear/feel younger in their old age should be more prone to get cancer. A testable proposition.

My understanding is that we all have cancer cells in our body — the problem becomes when they get triggered. There may be something in the immune system that has something to do with this. What depresses me with this subject is that it seems like the more we know about it the more we understand how much more we really need to learn. Also as I get older I keep coming across more members of my peer group (and people I know who are older) who get some form of cancer. It seems like we've made some progress in my lifetime, but it's too slow for my tastes. In my dream of dreams someone would come up with a silver bullet.

Re: Reddit user explains aging vs cancer

#13

Post by [deleted] »

michaelpinto wrote: post #11
rsheridan6 wrote: post #3

If this idea is true, people who appear/feel younger in their old age should be more prone to get cancer. A testable proposition.

My understanding is that we all have cancer cells in our body — the problem becomes when they get triggered. There may be something in the immune system that has something to do with this. What depresses me with this subject is that it seems like the more we know about it the more we understand how much more we really need to learn. Also as I get older I keep coming across more members of my peer group (and people I…

[deleted]

Re: Reddit user explains aging vs cancer

#14

Post by reasonattlm »

Just to be finicky, cancer is not in fact worthy of being called the "inevitable killer of mammals," through might be accurate in calling it the inevitable killer of mice, as said beasts are little cancer factories.

In humans, supercentenarians (110+) don't tend to die of cancer - in fact your odds of dying from cancer appear to decline precipitously past the 80s and 90s. I'd wager we won't know definitively why this is the case before there are good general cancer therapies in circulation, though.

The condition that presently acts as a final full stop to catch everyone lucky enough to miss out on all of the other fun little fatal surprises at the decaying end of life is called senile cardiac TTR amyloidosis. Some description:

http://www.fightaging.org/archives/2008/12/an-interview-with...

The short of it is "gunk clogs the tubes" but the long of it is much more involved - and like many things found in aging it has a rare youthful variant probably caused by unlucky genes. I note that the SENS Foundation puts some funding towards work on the narrow range of promising therapies for this condition:

http://www.fightaging.org/archives/2010/09/sens-foundation-f...

Re: Reddit user explains aging vs cancer

#15

Post by Read_the_Genes »

Thank you for linking to this interesting discussion on Reddit. Their discussion lacks a few key points.

First, inflammation is an important cause of cellular (and DNA) damage. The standard weapon used by your innate immune system is super-oxide, a free radical! Avoiding chronic infections is likely to be an important key to longevity, especially for those prone to inflammation.

Second, while "aging" is a natural mechanism by which your body defends against cancer, "aging" quickly is not the ideal way to prevent cancer.

Your cells will stop dividing when they have reached their Hayflick limit. This limit is not exactly caused by telomeres, but rather the lack of telomerase (a protein that lengthens telomeres). Active telomerase is necessary for a cell to become cancerous.

So the cell has its own built in mechanism to determine when it has divided too many times, as well as when it has accumulated DNA damage from external sources like UV or oxides. Your cells have "aged" when they have accumulated too much DNA damage! So aging, in this sense, is not a good way to prevent cancer. The aged body is filled with tumors that are near metastasis, and undergoes drastic changes (eg. reduction in hormones) to prevent cancer formation.

The only real way to prevent cancer is to stop cell division. This, of course, is not ideal. How would we grow to become an adult without cell division? How would we heal damaged tissue? The answer is actually in the growth pathways of mammals.

It turns out that dwarfs (little people) have very low cancer rates. See for example: http://www.scientificamerican.com/article.cfm?id=defective-g...

These people lack a gene (in a pathway) that is necessary for cancer to form. Knocking out genes in growth pathways in mice drastically reduces their cancer rates (the mice are also small). Want to prevent cancer? Stop growing!

This is completely unrealistic, of course. However, populations with limited activity in their growth pathways will be less prone to cancer. This extends to short people too, not just dwarfs.

Re: Reddit user explains aging vs cancer

#16

Post by Read_the_Genes »

michaelpinto wrote: post #11
rsheridan6 wrote: post #3

If this idea is true, people who appear/feel younger in their old age should be more prone to get cancer. A testable proposition.

My understanding is that we all have cancer cells in our body — the problem becomes when they get triggered. There may be something in the immune system that has something to do with this. What depresses me with this subject is that it seems like the more we know about it the more we understand how much more we really need to learn. Also as I get older I keep coming across more members of my peer group (and people I…

We all have tumors in our bodies, not cancer. Cancer is when the tumor metastasizes, and begins to grow out of control.

Perhaps instead of hoping for a silver bullet to cure cancer, determine when/if your body is full of tumors, and do everything you can to prevent them from accumulating any more DNA damage.

Re: Reddit user explains aging vs cancer

#17

Post by JunkDNA »

bronson wrote: post #10
nphase wrote: post #9

So the natural question is - what can one practically do to try to postpone DNA damage as much as possible?

3rd paragraph: "If you have a healthy diet low in sugar, high in antioxidants, in theory you can reduce DNA damage, keeping your DNA looking younger", etc... Eat your leafy greens.

With respect to antioxidants, there had been mounting evidence recently that antioxidants could paradoxically increase cancer risk. The evidence so far is that there are cellular pathways that spool up in the presence of oxidants and can cause cells to undergo cell death. Antioxidants can hinder these pathways from firing and instead, allow cells to linger around longer than they should.

Re: Reddit user explains aging vs cancer

#18

Post by davi »

I subscribe to the Disposable Soma theory of aging. http://medicine.jrank.org/pages/1758/Theories-Biological-Agi... [1]

In this scheme cancer is just one example of the balance between somatic maintenance and reproduction rate.

[1] The disposable soma theory of aging predicts that species and cohorts in a population expecting, on average, to have high survival and low reproductive rates should invest more heavily in protecting their somas than species and populations that expect a short lifespan and to reproduce rapidly

Re: Reddit user explains aging vs cancer

#19

Post by barry-cotter »

nphase wrote: post #9

So the natural question is - what can one practically do to try to postpone DNA damage as much as possible?

The only treatment that has large proven effects is calorie restriction[0] although that really lowers ones quality of life. Intermittent Fasting [1] seems to have many of the same benefits without being anywhere near as hellish.

[0]http://en.wikipedia.org/wiki/Calorie_restriction

[1]http://en.wikipedia.org/wiki/Intermittent_fasting

Re: Reddit user explains aging vs cancer

#20

Post by klenwell »

reasonattlm wrote: post #14

Just to be finicky, cancer is not in fact worthy of being called the "inevitable killer of mammals," through might be accurate in calling it the inevitable killer of mice, as said beasts are little cancer factories. In humans, supercentenarians (110+) don't tend to die of cancer - in fact your odds of dying from cancer appear to decline precipitously past the 80s and 90s. I'd wager we won't know definitively why this…

I read Long For This World and both gunk and cancer were on Aubrey De Grey's list of 7 Deadly Killers (or whatever it was). The impression I came away with from that book was gunk was a plausible target for future technological remedy but cancer presented a much more difficult problem (for reasons explained in the book.)

The careful qualifications to your case above seem to catch this objection, but based on my reading that book, I would gather that supercenternarians dying of gunk not cancer aren't necessarily immune from cancer. They may just be lucky in that gunk, at this period in history, got to them first.

If it isn't luck but something else, there's also the problem of extrapolating a therapy from that. De Vere's solution to cancer was replacing every cell in the body every 7 or 8 years to circumvent the effects of telemerase ( or something like that, I'm not a gerontologist obviously.) It would be interesting if these supercenternarians's bodies were doing something like this, but it would be more interesting if it led to a more practical therapy.

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