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.
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.
Those dwarfs seem to get even less cancer than you would expect given the reduced number of cells.
Also, on a related note, there's Peto's Paradox about why cancer rates are similar across species despite vastly different sizes (mice, humans, whales).
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.