Can I Live To Be 125?

By Jonathan Weiner

Walking and talking get more difficult for my mother every day, and when I phoned to tell her the headline of this story, there was a long pause before she found the words to reply: "I don't recommend it."

At 75, she is fighting one of the innumerable syndromes that elderly flesh is heir to. For reasons that no neurologist can explain, many of her brain cells are filling with debris called Lewy bodies. Her symptoms resemble those of Alzheimer's, and like Alzheimer's, the condition is sometimes genetic.

Do we have to grow old so sadly? Before we go, do we have to lose most of the natural gifts that make life worth living? We are the first people in human history for whom this is a primary concern. For every generation before ours, the first concerns were Can I grow old? Will my baby reach a ripe old age? Please let us grow older! Now the average life expectancy in the U.S. has advanced from 47 in 1900 to better than 76 in 1999. During the next century, new biological discoveries should ensure that even more of us will live to see old age and will encourage us to dream, in wild or wistful moments, that we might not have to grow old at all.

Whenever I want to feel optimistic, I think about work in progress in the laboratory of Seymour Benzer of the California Institute of Technology. Benzer made the first detailed map of a gene's interior, and he and his student Ronald Konopka discovered the first so-called clock gene, which ticks away inside virtually every living cell, helping tell our bodies where we are in the daily sweep from morning to night. Now, at 77, Benzer is searching through our genes for a sort of clock of clocks that tells us where we are in the sweep from the cradle to the grave and decides how fast we age. Recently he discovered a mutant fruit fly that lives more than 100 days, about one-third longer than the rest of the madding crowd in a fly bottle. What makes the difference is a single gene, which Benzer calls Methuselah.

If one gene can do that much for flies (or worms or mice--genetic engineering has created a growing zoo of Methuselahs), then what can our genes do for us? Maybe there really is a clock of clocks, and maybe, just maybe, 21st century biologists will figure out how to twiddle and reset the hands. They might concoct Methuselah pills or inject Methuselah genes into fertilized eggs and fool our mortal bodies into believing that we are forever young. "Perhaps," Benzer muses, "aging can be better described not as a clock but as a scenario, which we can hope to edit." If we died in old age at the same rate we die between ages 10 and 15, then most of us in the U.S. would live 1,200 years. We would outdo the first Methuselah, whose years were 969.

We are already doing better at preventive medicine and at repairing old bodies--dealing with abdominal fat, atherosclerosis, blood pressure, blood sugar, cataracts and so on. U.S. pharmaceutical companies have nearly two dozen Alzheimer's drugs in the works. In the next century, molecular biologists are likely to tinker with more and more of our genetic machinery, in what may be either mankind's worst folly or the most significant software upgrade of the 21st century. (Caveat emptor, users of version 1.0!) Just last month, biologists announced the discovery of mutations that accumulate in aging mitochondria, which are our cells' batteries; maybe someday they will learn how to keep our batteries from winding down. Scientists may also learn to repair our telo meres, the tiny ties at the ends of each chromosome that help hold our genetic bundles together but fray with age. Researchers may even learn to grow whole new hearts and livers from stem cells, a prospect I find slightly dispiriting. Will we walk off the stage at last elaborately disguised, a living prosthesis--false teeth, false eyes, false taste buds, false everything?

Of course, on this question of old age, science is still a baby. There are plenty of biologists who believe that aging and death are as inevitable as taxes. No one really knows if human longevity will come up against a fixed barrier somewhere or if, like the sound barrier, it is there only to be broken. Some gerontologists say the limit of the average life-span is 85 years; others, 95, 100, 150 and beyond. No one understands the economic barriers either. Ronald Lee, a demographer at the University of California, Berkeley, calculates that for each year we add to the average life-span, the economy will have to grow 1% to pay for our care.

After more than 50 years in the laboratory, Benzer has too much respect for life's complexities to believe in quick cures or fountains of youth. He often works through the night on his mutant Methuselah. He feels that aging should now be studied as a disease, and he would love to spend his next career, he says, "unraveling the facts." But he hates to see the study of longevity being overblown by the press. "I hope the hype will not result in the same letdown as Nixon's all-out war on cancer." Even if there is a central clock, it may be harder to control than cancer.

Chances are that my generation will consume all manner of antiaging drugs and nostrums--antioxidants, growth hormone, vitamin D, garlic, red wine, melatonin, blueberries--and in the end we'll still live only a little longer than our parents. Today in Japan a clothing company is cashing in with "antistink" underwear for middle-aged men, who (according to the company) begin to emit odors. But by the time we die, or shortly thereafter, the expansion of youth and the postponement of old age may become one of the greatest enterprises of the 21st century. "I see it as inevitable," says evolutionary biologist Michael Rose, who breeds strains of long-lived flies in his laboratory at the University of California at Irvine. "I'm confident that Benzer's work--and the worm people's and maybe my work--will someday be used by a bunch of avaricious corporations who'll make billions of dollars a la Microsoft by giving people what they've always wanted."

I wouldn't want to live as long as Methuselah, myself. But I would like to reach old age alive and kicking. My hope is that the science of life will mature fast enough so that 30 years from now, when my sons begin to ask those eternal questions about growing old, I can look at them and say, "I recommend it."

Jonathan Weiner is the Pulitzer-prizewinning author of The Beak of the Finch. His most recent book is Time, Love, Memory