Wednesday, September 17, 2008

Another birthday

Take a look at the schematic diagram above. Any idea what it represents? Well, I only know because I read the article by Jan Vijg and Judith Campisi, "Puzzles, promises and a cure for aging", in the August 28 issue of Nature.

The diagram shows three different biochemical pathways related to aging that are common across species. That is to say, you're looking at the downward slope to senescence and death. Not a pretty picture on one's 72nd birthday.

Our authors list the ravages of age, from flabby skin to loss of memory. Yeah, tell me about it. Apparently, natural selection never sorted out these problems because in earlier, more risky environments few people lived long enough for senescence to make a difference. But now, with the intervention of modern medicine, sanitation, food production, and exercise regimens, more and more of us are living longer and longer. Long enough for our cells to give up the ghost.

What nature didn't do, perhaps science can. That's the issue Vijg and Campisi address: What do we know about aging, and can it be stopped?

It turns out we know quite a bit. And extended lifetimes have been achieved in certain other species. Vijg and Campisi see no intrinsic reason why human senescence might not be delayed, and maybe eliminated. But they aren't immediately hopeful. "Can we mimic the evolutionary process to the extent that senescence becomes essentially negligible?" they ask. Their answer: "At this stage the answer must be that we do not know. Although there is no scientific reason for not striving to cure aging -- similar to what we profess to do for cancer and other diseases -- our current understanding makes it impossible to assert that indefinite postponement is feasible." Which is perhaps just as well, given the staggering social and economic consequences of longer lifetimes.

John McCain is my age and he wants to be president. I'll settle for a nap.