A WRINKLE IN TIME

Though death is still as inevitable as taxes, future generations may age more slowly and live significantly longer. Here are five scientists in the vanguard of research, offering new insights into the biochemistry of aging--and opening the door for life-lengthening drugs. Their approaches vary, but they share the belief that the human life span is not fixed.

Enhanced: TARGETED GENES ARE MORE ACTIVE IN FIGHTING AGING

The "guess your age" booth at a carnival isn't often exactly right. But it's not usually as off-base as Cynthia Kenyon's colleagues. A few years ago Kenyon, a molecular geneticist, had one of her grad students cart a tray of worms around her lab, asking people how old they thought the worms were. Most said about 5 days. What they didn't know was that Kenyon had tinkered with the worms' genes. The squirmy creatures had the perfect health of 5-day-olds, but they were 144 days old--six times their normal life span.

Over the last decade, Kenyon's continuing work has shown that "you can make huge changes in life span so easily"--in worms, at least--by changing hormone levels and enhancing the effects of fewer than 100 genes. Some of the target genes produce antioxidants; some make natural microbicides; some are involved in transporting fats throughout the body, and some, called chaperones, "keep the cell components in good working order," says Kenyon. What they all have in common is their effect on aging. The more active the genes, in general, the longer an organism is likely to live.

When Kenyon's work with worm genes was first published in 1993, skeptics predicted it wouldn't translate well to humans. One hundred forty-four days might be ancient for a worm, but a far more complex human being can already expect to live about 200 times longer than that. Scientists still don't know exactly why the life spans are so different, much less what a change in a worm's life span might mean for a person's. Nonetheless, much of the cellular machinery in worms closely resembles that in higher mammals. That finding has opened the door for a neutraceutical company, Elixir, which is trying to develop a drug that would yield the same kind of results as Kenyon's genetic tampering. "I'm not saying that with a few changes humans could be immortal," she says. "But it'd be like looking at an 80-year-old and thinking he was 40." Who could object to that?

Stressed: CHRONIC TENSION MAKES CELLS DETERIORATE FASTER