There's a new notion about old age: Advanced years don't have to be empty years. Even the oldest old can lead productive, fulfilling and independent lives.

As more and more people pass the century mark without a second glance, they are setting examples that are changing our ideas about aging.

At 104, Mary Sims Elliott was working on her autobiography, writing poetry and trying to influence her church's position on social issues. Now she's 105 and her autobiography, titled My First One Hundred Years, was just published.

At 105, Geneva McDaniel taught aerobics daily at her senior citizens center. Now she's 107 and recruiting residents of her retirement community to exercise with her.

At 106, former sharecropper Jessie Champion and his 86-year-old wife, Fronnie, were weeding and harvesting their garden. Recently, Fronnie passed away and now Jessie, now 107, lives and gardens with his daughter.

These vibrant centenarians are among more than 150 who have volunteered for the Georgia Centenarian Study, a decade-long project that explores not just why some people live so long, but how they do it so successfully.

"We want to see what influences longevity and adaptation in old age," said Leonard W. Poon, who directs the UGA Gerontology Center and heads the study. "The primary focus is to understand patterns specific to each age [group] and to individuals in their 60s, 80s and those over 100 years of age who are community dwelling and cognitively intact."

Since 1988, Poon has directed the study that includes nearly a dozen faculty from the University of Georgia, the Medical College of Georgia and Iowa State University, along with dozens of graduate students. Representing many academic fields, the researchers study "expert survivors" -- people who've passed their 100th birthday, live independently or semi-independently, are active in their communities and enjoy relatively good physical and mental health -- and compare them with people in their 60s and 80s.

"We all have stereotypes of what a centenarian should be," Poon said. "But there's no such thing as a typical centenarian."

Nonetheless, the researchers have drawn a composite picture of an expert survivor in the Georgia study. She is a female with a grade school education who:

By and large, expert survivors also are focused on the here-and-now and are just as active in mind as in body. Just how these spry individuals got to be so old is a puzzle for centenarians and researchers alike.

Some of the oldest old chalk it up to luck. And some, including Jennie V. Williams, 105, say the "good Lord" isn't through with them yet. Others, like Mary Sims Elliott, say they're just too busy to die.

Clues to Longevity

After intensive analysis of biological, psychological and social factors that may contribute to successful aging, the researchers haven't found any fountain of youth. While they have charted some striking similarities among expert survivors, the researchers also have observed many differences.

"You can't make generalizations about these very exceptional people because each one is different," Poon said. "Centenarians continue to surprise us so that now surprises are the rule."

Among the surprises is that "some centenarians turn us down because they are too busy to participate. They are on college boards or run their own businesses," said Martha Bramlett, an assistant professor of nursing at the Medical College of Georgia who manages data acquisition for the study.

No two centenarians are the same. "For as many optimistic people, we find as many who are grumpy," Poon said. "Successful aging has many, many components."

"Centenarians are far more different than they are alike," said Peter Martin, a former UGA faculty member who co-directs the study and is now a professor of human development and family studies at Iowa State. "There are many paths to longevity, and each situation is very different."

Take a family history of longevity, for instance.

"People aren't likely to live long just because their parents did," Poon said. "It seems the genetic contribution is important for some centenarians who come from a long line of long-lived people. But we have as many people who do not come from long-lived families."

Funded by the National Institute for Mental Health, the study couldn't come at a better time. Post-retirement citizens may be in the minority now, but that trend is changing fast. Senior citizens are already the fastest growing segment of the American population, and the 85-plus group may be the fastest growing among senior citizens, Poon said.

By the year 2025, the number of people under age 20 is expected to equal the number of those 65 and older, according to reports published by the Joint Congressional Committee on Aging.

"People 65 and older are just now becoming a population for us to think about in terms of health care, jobs and the economy," Poon said. "When that of proportion is the same as the young people, this becomes very significant in terms of the work force, health care and retirement."

The research team's findings will have effects that ripple far beyond the families of silver-haired Americans. Their findings will help scientists, medical and social agency personnel, and elected officials better understand the aging process and prepare for the centenarian population explosion that demographers and census takers have predicted.

"The research will help our country provide the services needed as more people survive to be 100," Poon said.

Like centenarians everywhere, those in Poon's study come from all walks of life. Some have doctoral degrees; others never finished grade school. Some live alone in spacious homes; others are so poor they lack even the basics such as a refrigerator. Several have a wealth of family and friends they call on for aid; others rely on their wits to build a support network of friends and neighbors.

Regardless of their lot in life, though, expert survivors face similar challenges unique to their age group. With few road signs to guide them, they have adjusted to diminished physical strength, faced the deaths of numerous -- often much younger -- loved ones and found answers to life's meaning and purpose long after retiring from conventional roles as breadwinners and parents.

The centenarian research project looks specifically at how physical and mental health, intelligence, memory, coping skills, personality traits, attitudes, nutrition, spirituality, family history, support systems and religious beliefs influence a long and independently lived life.

During phase one of the two-phase project, the researchers ask participants a battery of questions and collect bundles of data on everything from what they ate for breakfast to what makes them happy or sad. Then they compare the relative significance of each variable -- both for individuals and for age groups -- to determine which ingredients are important in the recipe for longevity.

Phase One: Many Roads to Longevity

So far, what the researchers have found in phase one is that no one variable stands out as more important for longevity. Moderation, however, "seems to come up frequently and to be practiced over one's lifetime," Poon said.

That may help explain why expert survivors are so hale and hearty.

"We were surprised to find very little depression among the centenarians," said Martin, who directs the project's personality, life events and coping component. "These people have a high degree of self sufficiency and are confident and resourceful in their ability to overcome obstacles and problems.

"They describe themselves as I-can-do people. In fact, overall, their mental health and life satisfaction are very high," he said.

But don't expect them to conform.

"Instead of growing more alike, people become more distinct, more differentiated, more individualized and unique as they grow older," said Philip Holtsberg, one of Poon's doctoral students. "And the longer they live, the more pronounced those differences become."

Even past the age of 100, though, centenarians still conform on some things, like good health. About 50 percent of them try to avoid fats in their diets, said Mary Ann Johnson, who heads the study's diet and nutrition component. They also eat more fruits and vegetables, get slightly more vitamin A and carotene, and consume about the same amount of calories and fat as their younger counterparts.

Among centenarians, age, however, is not the primary predictor of nutritional risk, those factors that may contribute to poor nutrition such as wearing dentures, taking medications that upset the stomach or smoking. Emotions play a bigger role.

"How you feel -- happy or sad, understood or misunderstood -- is more important," said Johnson, a UGA professor of foods and nutrition. "Aspects of mental health and the number of illnesses, more than age, predicted nutritional risk among centenarians."

Expert survivors tend to be healthy and proud of it. Surprisingly, the researchers found no significant differences among people in their seventh, ninth and 11th decades in the number of medications taken, trips to the doctor or hospital, or recent illnesses.

More than 60 percent of the centenarians rated their health as good to excellent; an even higher percentage said it was as good or better than five years ago, said Martha Bramlett of the Medical College of Georgia.

"We know we get a skewed view of the health of centenarians in general because we only look at those who are still community dwelling," Bramlett said. "But our check-ups confirm that they are in remarkably good health. One gentleman, David, who is 105, still reads without glasses and has 20-25 vision. Julia, a retired seamstress still threads her own needles at 100."

Successful agers also know the value of daily activity and mobility, and make an effort to get exercise, Bramlett said.

Take Frank, 101, who drove to his job at the courthouse every day until his recent cataract surgery. Now he often walks to work. Then there's Sara, 101, who works all week keeping her own yard, flower beds and home tidy and neat. On weekends she travels to Atlanta to clean house, do laundry and babysit with her great-grandchildren so her granddaughter, who has health problems, can rest.

The research team also looked at the influence of religious beliefs on physical well-being as well as on other factors. Although all three age groups scored high on the importance of religion in their lives, the researchers found this had no strong correlation with physical or mental health, personality or life satisfaction. This finding may be influenced, in part, by the uniform level of high religious influence in all three age groups, said Bradley C. Courtenay, a UGA professor of adult education who examined the relationship between religion and longevity.

Coping with hardship or loss, though, is another matter, Courtenay said. Expert survivors rely more on spirituality and a deep trust in God and less on non-religious methods than the other groups do.

"Centenarians tend to have a philosophy and keep with it, but they don't tell people about their philosophy," Courtenay said. "They think everybody is supposed to have their own, so they're not imposing."

The Second Time Around

Now that researchers have a "group snapshot" of people in their 60s, 80s and 100s, they want a clearer picture of how each age group as well as each individual within the group changes with the passing of time.

"Because people's life experiences influence the aging process, we don't know whether it's age or peer-influenced differences we are observing," Poon said. Phase two of the study provides a sharper focus on which changes are related to aging and which are peer-influenced, such as having been the same age during the Great Depression or World War II. Researchers re-test 60- and 80-year-olds after five years, 100-year-olds after 18 months.

"There are few longitudinal studies with centenarians because once they reach 100, we're finding that life expectancy is only about 12 to 20 months, and if we wait too long, then we may lose them," Poon said.

Sadly, that already has happened with some, including Elva "Speegie" Spangenberg, a centenarian well-known to Atlantans, who died last December at age 107. At 98, she began a new career as a tour guide at Rhodes Hall, an Atlanta historic site that was seven years her junior--but had to retire her post because of a fall about a year before her death.

"We've had counseling sessions for our testers to make sure they could deal with a centenarian's death. They get very attached to the centenarians. It's like a family member dying," Poon said.

Phase-two testing of the centenarians, which is a repeat of the tests used in phase one is often hard to conduct for other reasons, too -- mainly because of their physical and mental decline. Poon predicts only about half of the original group will be able to participate.

"Those who are still around for the second round of tests are often too frail to be tested for any length of time," he said. "We are finding that 18 months often is too long."

Poon illustrates the point by recalling "one lady who played ragtime piano for the testers on their first visit. Her functional mental state was practically perfect," he said. "Eighteen months later she could not answer many of the same questions. It was heartbreaking to see her go from living an independent life in her own apartment to one in a nursing home."

Poon wants to expand the study to include institutionalized centenarians and compare them to the community-dwelling individuals. He also wants to continue studies of dementia among the oldest old, a project he began last summer with researchers at the University of Lunde, Sweden.

For now, though, those plans are on hold; he and his team of researchers still have plenty of phase-two data to collect, not to mention mountains of data from both phases to analyze. Then there's the monograph on centenarian health issues that he and researchers from France, Hungary, Japan and Sweden plan to publish next spring.

"I think longevity around the world is an important issue," he said. "Researchers from different countries look at it somewhat differently, but we also have common hypotheses and approaches."

In the meantime, Poon et al. have been adding more centenarians to their study. But finding people who meet the study's criteria isn't easy.

"We go to a lot of chicken dinners, talk to a lot of people and pass the word along through churches, senior centers and such," Poon said.

Potential participants must be screened to make sure they're cognitively intact. And that brings up another problem for centenarian researchers: The questionnaires, surveys and other tests they use were designed for and validated on much younger people. They may not hold true for older populations.

"Any time you use a survey, it has to be validated for that particular population," Poon said. "These people are outside of the range of an average life span. Since no one has tested 100-year-olds with these instruments before, we just don't know whether the tests work for the oldest old," Poon said.

Despite the necessary ground-breaking efforts, Poon said he is optimistic that the research will provide useful information. Although it's still too early to draw hard-and-fast conclusions from the phase-two data, a preliminary glance shows "tremendous amounts of individual differences," Poon said. "The changes in our centenarian group are very dramatic over the 18 months of study.

"As centenarians get closer and closer to death, I think a very different picture will emerge in terms of their functioning, but I could be surprised again. Some centenarians may maintain this profile of an independent, functioning person. After all, they've had this pattern for 100 years and 18 months may not change it," he said.

Even among the 80-something-year-olds, the researchers already have seen "a fantastic amount of change," Poon said. "They have already lived beyond the average age, and then we add five years to that."

Learning to Cope

While the researchers are interested in describing centenarians' physical and mental function, they are even more curious about how centenarians have compensated for their diminished abilities.

Poon speculates that the "cohort effect" -- common experiences shared by people born at the same time -- also will have a strong influence on how groups of people change over time.

"The influences of the environment, the context in which you grow up and the value system that holds you up all of these years will be very important," Poon said. "And we know your critical development stage in your 20s and 30s are important."

However, people in their 70s and older are in their last stages of development, which can be the most trying -- and the most rewarding. The longer people live, the more difficulties and losses they face. In addition to losing loved ones -- siblings, children and friends -- centenarians face the loss of career, mobility, respect and attractiveness. They even lose the feeling that they are making a contribution; often they're viewed as "has beens."

"The last stages of life may hold challenges to find ego integrity -- a wisdom or feeling that your life has made sense -- and not to give into despair," Poon said, drawing on ideas proposed by psychologist Erik H. Erikson who is noted for his work on ego integrity and ego development.

Despite the fact people cannot change many traits -- like personality or cognitive ability -- even at 100, people are still able to change some things.

For example, researchers have learned the importance of studying compensatory mechanisms like resourcefulness, which "may be a key ingredient to functioning independently or semi-independently in the community," Poon said.

Although few of us may live long enough to blow out 100 candles, we can still learn pointers from those who have, like the benefits of learning to cope with loss, adopting a positive outlook or finding a central purpose in life. The most important lesson centenarians can teach us may be that we're never too old to learn.

"No matter what your age, the memory is still trainable," Martin said. "You can teach an old dog new tricks. Centenarians can still use their minds, reflections and personality skills to compensate for or overcome problems."

And that's a good take-home message for us all. Especially since today's baby boomers are tomorrow's centenarians.

For more information visit www.thecentenarian.co.uk/home.htm