Life's Longevity

A hot topic in today's society is the search for longevity. Humans have always dreamed of living longer—even hoping for immortality. Countless individuals have, in one way or another sought the “Fountain of Youth,” or some type of elixir that will prolong life. We've become obsessed with counting the length of our existence, wishing to extend it. We hear about an isolated group of people living in a corner of Japan or Sardinia, whose members often live past 100; and we demand to know how they do it, and how we could copy it.

We zealously pursue the latest diet fad, consume books that promise secrets of longevity, and embark on yoga and exercise programs that will make us physically appealing and allow us to reclaim our youth. In these pursuits, we purchase enormous amounts of potions and pills—all in the name of acquiring and extending a robust existence. Billions of dollars are paid out in these pursuits—led by the super-rich, who seem the most consumed by the search.

Science lends its helping hand to the dream. Research on many biological fronts yields daily discoveries. Studies of short-lived critters, such as fruit flies and nematodes, subject them to genetic experiments, seeking to find gene modifications that could cause them to live longer. (Critters with a brief life span are chosen for these experiments, which allow researchers to examine several generations in just a few months, rather than over years.)

Some creatures are actually able to modify their lifespan, based on the environment they experience. The nematode Caenorhabditis elegans is a very tough critter. It possesses an extremely simple genome, so its genetic mechanisms can be readily manipulated in the lab, to explore various ways of delaying death. This nematode has a type of gene—called “gerontogenes”—that control aging. What longevity benefits might we reap, if we could master these genes in ourselves?

Some studies have shown that life can be prolonged when one's diet is restricted. Rats who have been fed nearly half their normal intake can live half again as long as their well-fed siblings. Moreover, they have fewer diseases. It seems that, when energy is limited, one's metabolism shifts into longevity mode. When times are plentiful, however, we throw caution to the wind and live faster, more reckless lives. So should we seek to be skinny?

Other scientific studies focus on a very different class of animals: jellyfish. The jellyfish species Turritopsis can literally rejuvenate itself. It even seems to age in reverse, when, under certain conditions, it will sink to the seafloor, revert back to an earlier form of life, and begin again. It may be that their stem cells have an unlimited capacity for self-renewal.

So the pursuit of immortality continues—despite the fact that we have no idea of what it might bring. Would a life everlasting lead to everlasting boredom? We don't stop to ponder that question, as we relentlessly pursue an endless existence. Maybe Nature has a good reason for limiting life spans. Isn’t death necessary, in order for the great recycling process to continue? Thus everything—animals as well as rocks—has a finite life.

A more troublesome thought: What if only the richest people could afford to extend life far beyond the current norm? Would we end up with a divided society consisting on the one hand, of the privileged, who live long, and on the other hand the short-lived poor, who are dominated by the privileged, as if they were animals? Isn't there already enough class separation today?