The Centenarian Club doesn't particularly care that scientists predicted recently that 85 will always be the upper limit of average life expectancy, even if medicine conquers cancer and heart disease.
"There are already a lot of people aged 100, and in the next century being 100 will happen to more and more people," maintains Suzanne Ricklin, 43, co-founder of the Columbia-based organization for people who want to live 100 years.
"Joining doesn't ensure that someone is going to be 100, obviously; it's something to shoot for. We want to be here for a really long time because we have a lot to do and a lot we enjoy doing," says Ms. Ricklin, a social worker who says she has found in her practice people who change their attitudes about living often change their lives as well.
But when the report on life expectancy in the Nov. 2 issue of Science magazine became public, some people were more concerned than the upbeat Centenarians.
"Barring major advances in the development and use of life-extending technologies or the alteration of human aging at the molecular level, the period of rapid increases in life expectancy in developed nations has come to an end," researchers at the University of Chicago and Argonne National Laboratory said in the article.
Immediately, the phone began to ring in Richard Suzman's office at the National Institute on Aging.
"People who were approaching 85 called; they were worried that they had no time left," says Dr. Suzman, chief of demography and population epidemiology in behavioral and social research at NIA.
Other studies have established higher caps on average life expectancy, Dr. Suzman says. But there's even better news than that for frightened octogenarians: Nearly 3 million Americans are already past 85. Known as the "old-old," this age group is by some measures the fastest growing part of the population as a whole, and at other times the fastest growing part of the population past 65.
And, he adds, "the number of centenarians [people aged 100 or more] is growing at four times the rate of people over 85."
That might seem contradictory, but the confusion is really a matter of semantics and statistics.
Average life expectancy is an estimate of the age at which 50 percent of people born at a particular time will have died. At that point, the other 50 percent is still alive, for reasons of heredity, healthy living, effective medical care and plain good luck. Today's over-85s, in fact, have far exceeded a life expectancy that was just 47 years when they were born.
And although experts discount stories about tribes of ancient people sustained by goat-milk yogurt and tranquility in Asian mountain ranges, they do talk about a "verified" life span of 120 years for one individual.
Most of them also believe there's a cap on the life span, a poinat which the body's cells stop replacing themselves; but no one knows what that limit is, or how it will be affected by medical knowledge, lifestyle habits, economic factors or ecological changes.
"Life expectancy for people born today is a demographic guessand it could be badly wrong," says Dr. Reubin Andres, clinical director of the National Institute on Aging. "These numbers almost always underestimate because one doesn't know what will happen. For a newborn, there's no way to predict what the medical advances will be, or what the quality of air and water will be, or what horrible new epidemic will have an impact."
Nevertheless, life expectancy predictions are important -- for health and social planners and for insurance actuaries. For individuals, especially for older individuals, improvement in the quality of life probably has more immediacy than attempts to determine quantity of life. "People live longer, but their lives are not necessarily better," says a new book produced by an expert panel assembled by the National Institute of Medicine. Titled "The Second 50 Years," the book assumes we can expect a long life span, and therefore argues for greater efforts to improve the quality of life for the elderly through more research, earlier treatment and greater efforts at rehabilitation of those already frail and disabled.
"As the Gray Panthers used to say, 'We want to add life to years, as well as years to life,' " says Pearl S. German, professor in the department of health policy and management at the Johns Hopkins School of Hygiene and Public Health, and a member of the expert panel.
"The aim is to have morbidity [sickness] confined to a very short period," she continues, explaining that some scientists talk about a time when morbidity has been reduced to the point that "we function right up to the end, and then fall apart like the 'One-Horse Shay.' Everything stops simultaneously."
To achieve that, the book urges that people past 50:
* Have their blood pressure checked at least once every two years, even if they have no risk factors or past episodes of hypertension.
* Have immunizations against pneumonia and influenza.
* Have regular dental care.
* Stop smoking.