Passage II

SOCIAL SCIENCE: This passage is adapted from the article "Design for Living" by Polly Shulman (©2000 by Scientific American, Inc.).

At 85, Jeanne Calment of Arles, France, took up fencing. She outlived all her descendants. Asked at 115 how she saw her future, she quipped, "Short, very short." But she was wrong: she lived seven more years, dying on August 4, 1997, at 122 years, the longest verifiable life span of any human being.

Richard M. Suzman, an associate director at the National Institute on Aging, claims the rate of disability in all populations, including the oldest old, has been dropping since 1982. Demographers, geneticists and medical researchers hope that studying "the superstars of longevity" will yield vital clues to how all us can live longer, healthier lives.

To Leonard W. Poon of the Georgia Centenarian Study, there is no secret to longevity. Poon and his colleagues followed 144 cognitively intact, independently living centenarians. Some were compared with groups of people in their 60s and 80s from similar backgrounds; others were interviewed and tested every six months for what remained of their lives. He believes the most important lesson of the study is the qualities that stood out among the oldest old.

For example, few of the centenarians in the study smoked, were obese or drank heavily. They remained active throughout life, ate breakfast regularly, and consumed plenty of vitamin A and carotenoids by eating fruits and vegetables. "In terms of psychology and attitudes, they've resolved whatever issues they have, they're sure of themselves, and they want to have their way." Learning about the diversity of characteristics that centenarians share, Poon thinks, "isn't a bad result, because anyone can find one factor relevant to their lives, one thing that's possible to change. The diversity gives all of us hope to be able to live longer."

Poon, a psychologist by training, considers motivation and attitude as important as genes. But Thomas T. Perls, director of the New England Centenarian Study, believes some genes can guarantee their lucky recipients a better chance to live a long, healthy life, and he means to find them. Siblings of centenarians in his study have a five times greater chance than average of living to their early 90s and a 15 times greater chance of living to 100. Of course, siblings share environmental factors as well as genes. Could some of these be responsible? "Is it the chicken soup their mom makes?" Perls asks. "No, because their parents also live unusually lone."

Nir Barzilai, a gerontologist who collaborates with Perl's group, is looking for longevity genes as well. He and his colleagues study "founder populations"—small, genetically isolated groups that gradually expended to large numbers, all the while marrying within the community. One collaborator hunts through the genes of the Amish; Barzilai does the same with Ashkenazi Jews. The fact that members of such groups share large amounts of genetic material makes it easier to find relevant genes. The geneticists compare the genes of long-lived group members with those of members with short or normal-length lives. Because these people have so much genetic material in common, any genes found in the long-lived group but not in the short- or normal-lived group have a good chance of being the ones the scientists are looking for.

It’s important to Barzilai to find out what functions those genes perform, then develop medicines to mimic them. "If they have to do with oxidation, we'll try to manipulate oxidation. If they increase levels of HDL—that's the beneficial kind of cholesterol—maybe we can increase HDL. I had a 102-year-old who had a very high grade cancer, with a prognosis of two months, but she lived with it for five or six years. Maybe something in her genes protected her from this cancer." If so, understanding how that protection worked would help doctors develop cancer-fighting drugs.

Barziali and his team have been quizzing their centenarians for shared characteristics and, like Poon, have found a lot of diversity. Barzilai says, "One thing they seemed to have in common was some form of flexibility. Many of them had very hard lives. They rolled with the punches, got up and continues with a good attitude."

One problem is to separate cause from effort. Did Barzilai's and Poon's centenarians live longer because they rolled with the punches, or did 10 decades of experience give them the wisdom to accept experiences that would have thrown them for a loop in their youth? Centenarians researchers would like to go back in time and interview their subjects at 20, 50, 80—but of course, they can't.