Aiel and age?

[Thor]

peopel age because cells f*&$ up after duplicating 10000000 million times throughout a person's lifetime.  (cancer is due to this, you could argue that aging is like cancer too if you want, but people tend to be quite pedantic with the classification of different cancers as different diseases)

 

eventually the messed up cells become so much that parts of our body can no longer work, skin being most early to fail visibly as it suffers from external damage as well.

 

in aol, the medical science was presumably at the pinacle of understanding human biology and as such could have helped people survive much longer simply by preventing cells from duplicating badly.