In an effort to slow down — and even halt — the aging process, scientists are increasingly turning their attention to the various external and internal factors that give rise to it. As this new video by AsapSCIENCE shows, we're all slaves to a biological clock that's been ticking away since the moment we were born — and it's setting a hard limit on how old we can become.

In this "Science of Aging" video, Mitchell Moffit and Gregory Brown review the problems caused by cellular damage, the result of ever-shortening telomere lengths. Eventually, our cells lose their function and die. We experience this as aging, and ultimately, death.


Interestingly, these cellular replication limits may prevent certain cancers from arising.

It's also important to note that Moffit and Brown are grossly oversimplifying the aging process. Cellular senescence is clearly an important factor, but not the only one. Gerontologist Aubrey de Grey has isolated at least seven factors responsible for human aging:

  • The loss of cells that we need
  • The accumulation of cells that we don't need
  • DNA mutations inside the cell nucleus
  • DNA mutations inside the cell's mitochondria
  • The accumulation of "junk" inside of cells
  • The accumulation of "junk" outside of cells
  • The formation of cross-linked proteins outside cells

By framing it this way, de Grey and others are hoping to systematically tackle these various problems in an effort to slow down the aging process, and ultimately achieve so-called negligible senescence.