Check out this summary of results on aging in nematodes. The layman’s summary is this:
Aging is thought to be due to accumulated damage. As we age our bodies get lots of microscopic injuries and accumulated cellular damage. Over time it adds up and our bodies break down and we die. This is the prevailing hypothsis because it’s easy to see the mechanism for how it came to evolve.
An alternate hypothesis is that our genes dictate that we age and die, and it’s programmed into us. So rather than breaking down, aging is the result of changes in metabolic regulation.
This study finds evidence supporting the latter model, which is pretty interesting. To summarize their experiment they used gene-chips to exhaustively search for genes that change their expression level in old worms, and linked many of them to a single regulatory protein (transcription factor). Then they tried to put stresses on young worms to see if they could increase the level of this transcription factor, effectively making the worm age faster. They were not able to, which indicates that the transcription factor levels are not a function of stress. Of course, this is only true if they were using the “right” stresses on the worms.
In any case, I’m always excited to see work done that supports any sort of programmed-senescence model, because it points toward the possibility of regulating aging by only tweaking a few things.
This is promising stuff indeed. However, I cannot fathom the massive social upheaval that would occur if large amounts of the population could truly stay mid-20’s-esque until an accident eventually did the trick. A whole lot of things would have to change.