Frank Murray gets up before dawn every morning and goes through a series of exercises to keep his body limber.No big deal for a man in his 50s or 60s. But Murray's not 50, 60 or even 70. He's 101 years old - or young, if you look at life the way Murray does.

He still drives to church on Sundays. He still gets up and reads the newspaper every day. He still cooks, mostly stews that he loads up with vegetables.
Murray, of Hayward, Calif., has no magic elixir for a long life. He has the gray hair and wrinkles to prove it. 

Yet he belongs to an elite fraternity, the estimated 71,000 Americans who are 100 years old or older. And their ranks will grow. The U.S. Census Bureau projects that 114,000 Americans will be centenarians in 2010, a number expected to swell to 241,000 by 2020.

Why are so many living so long? Legions of scientists are probing the secrets of longevity, taking a hard look at everything from gray hair to damage deep within cells. They are trying to understand today's centenarians and to find ways to extend the human life span.

Medical advances of the past century, such as antibiotics and statin drugs for heart disease, already have allowed the average person to live decades longer than someone born in 1900. If those advances continue, will scientists push the envelope of human life far past 100? Can people routinely live to 150 or even 200?

Right now, most Americans say they don't want to live that long. A USA TODAY/ABC News Poll of 1,000 adults released today shows that Americans, on average, would like to live to be 87 years old, up from the current life span of nearly 78. Just a quarter of the people who responded to the poll said they want to live to be 100 or older. 

If researchers could make it possible to live to 120, most Americans would take a pass. Their reasons: Most worry that they'll become disabled by health problems and end up being a burden to their families.

But old age, as Murray illustrates, doesn't always translate to disability or even disease. And scientists already have made some progress toward provocative, futuristic therapies that would slow the aging process itself. 

Research by Richard Weindruch at the University of Wisconsin-Madison and others, for example, suggests that an extremely low-calorie diet, one right on the edge of starvation, pushes the life span of mice and other animals to an extreme. If people get the same benefit, some might live beyond 120, about the longest the human body is thought to be able to last today.

Other advances on the horizon include genetic research to identify those genes that might one day protect people from heart disease and other age-related killers.

The National Human Genome Research Institute, one of the National Institutes of Health, last week announced plans to use its gene-sequencing capabilities to search for the genetic roots of diseases that have long eluded scientists.

And scientists at the University of Utah and other research institutions believe that telomeres - long segments of repeated "junk" DNA on the ends of chromosomes - might hold the same key to human longevity that they do to the life of an individual cell. The Utah team linked shortened telomeres to higher death rates from heart disease and infections, speculating that telomere-lengthening drugs could add years to a human life.

Fountain of Youth 

Throughout history, humans have yearned for an elixir that would keep the body young forever. Spanish explorer Juan Ponce de Leon discovered Florida in 1513 while searching for the Fountain of Youth, a mythical spring said to restore youth.

Ponce de Leon died trying to find those magical waters, and people continue that search to this day by logging onto websites hawking pills and potions said to delay aging.

Even the scientific community is not immune: Scientists first looked at estrogen replacement therapy and then at testosterone as the modern-day version of the Fountain of Youth. Then human growth hormone was touted as a cure for old age.

But so far, the fountain remains elusive.

"Nothing discovered yet has been shown to stop or slow down aging," says Robert Butler, president of the International Longevity Center-USA. Still, Butler and other experts say that discoveries being made today can help people live longer and healthier lives, continuing a trend that began a century ago.

"A baby born today has a 50% chance of living to about 79 or 80," says Leonard Hayflick, a researcher on aging at the University of California, San Francisco. Public health advances such as clean public water and the development of antibiotics have added decades to the average life expectancy.

The average American born in 1900 was only expected to reach age 47, according to the Centers for Disease Control and Prevention. By 1960, he or she could expect to be around until about 70. Life expectancy has gone up steadily since, hitting 75 in 1990. 

Increases in average life expectancy have been less dramatic in the past 20 years, and the nation's obesity epidemic could further slow progress. But better treatments for chronic conditions such as heart disease pushed life expectancy to about 78 in 2003. 

The trend toward greater longevity is expected to swell the ranks of Americans age 85 and older to nearly 7.3 million by 2020 from 5.1 million today, according to the Census Bureau. 

By 2050, the bureau projects that nearly 21 million people age 85 and older will account for 5% of the nation's population - nearly three times the 1.7% share that age group holds now.

Machinery wears out 

But experts such as Hayflick say there's a limit to the rise in life expectancy. Humans, he says, simply aren't built to live for 150 or 200 years. "Our body parts, like the parts in an automobile engine, can't work forever," he says.

The oldest human on record, Jeanne Calment of Arles, France, died in 1997 at the age of 122, probably from heart disease, which can develop late in life and kill even the most hardy centenarian, says Thomas Perls, director of the New England Centenarian Study at Boston University.

Experts say super-agers such as Calment are rare: "Only a small number of people have the potential to live that long," says Jay Olshansky, a demographer at the University of Illinois at Chicago.

People who live 100 years or longer probably inherit genes that slow the aging process or protect them from diseases such as cancer or heart disease, Perls says. Eventually, however, the wear and tear of many decades finally catches up, he says. Damage to the immune system can take its toll, leading to an infection that leads to death. Or a chronic disease such as clogged arteries might get worse in the last few years of life and trigger a heart attack.

Perls and his colleagues are finding that siblings of centenarians have a greater chance of living into their 90s. His team and others are searching for genes that might offer a longevity edge.

Researchers also are probing the biochemical basis of old age, looking for substances that might slow the wear and tear.

Oxygen is crucial for life, but scientists know that breathing exposes cells all over the body to toxic molecules called free radicals. Those free radicals can damage DNA and the inner machinery of cells, says Caleb Finch, an expert on aging at the University of Southern California.

Humans have a raft of repair mechanisms to deal with the ongoing injuries, Olshansky adds. But over time, the cumulative damage can cause body parts to break down, he says.

"Lots of things go wrong in people who live past 80," Olshansky says. "The things that go wrong are a result of operating the body past the warranty period." 

After age 80 or 85, he says, most people can no longer keep up with the damage. In the last years of life, the mounting damage can lead to hearing loss, aches in joints that have lost much of their protective cushioning, eyes that can't make out the fine print and a host of other age-related changes.

Things just don't work the way they used to at age 20. 

No anti-aging pill soon 

The search for longevity genes might lead scientists to a drug that can slow the aging process.

So could a controversial low-calorie diet, one that allows mice and rats to live 30% longer than usual. If humans get the same benefit from that diet - and that's a big if - researcher Weindruch believes that scientists might be able to find a pill that does the same thing.

If so, people could eat a normal diet and still beat the longevity odds. "You could live longer than 90, and possibly up to 120," he says.
Just don't count on an anti-aging pill anytime soon.

"There's nothing you can take now that will make you live longer," says David Finkelstein at the National Institute on Aging's Biology of Aging program. 
Figuring out the nuts and bolts of the aging process will take decades or longer, he says. Even then, researchers may never find a pill that holds the line on old age itself.

But recent research has revealed some of the secrets to aging well. They sound suspiciously like the advice your mother gave you: Eat your vegetables. Go outside and play. But experts say they offer most people a shot at living longer, healthier lives.

"Some people really do want to live forever," says Christine Himes Fordyce, a geriatrics expert at the Group Health Cooperative in Seattle and co-author of a book on aging. "But most people just want to live as healthy and as full a life as they can."

Rosa Lee McGee, 102, is an example of someone who leads a full life at a remarkable age. She started work at 21 and continues to this day, working two or three days a week as president of the Tenants Affairs Board at her St. Louis apartment building, a post she has held for the past 23 years.

She tried retiring a couple of months ago but was talked out of it. "They just will not turn me loose," McGee says.

Her secret for a long life?

"The Lord keeps me, my dear. I don't keep myself."

Studies suggest that people who remain healthy and vital far into their 80s or longer share some common characteristics. They're rarely obese. They get enough exercise. They eat healthful foods. And Fordyce says they have something else that gets them up and going every day: close ties to friends and family.

Details in a well-lived life 

Murray has never been overweight, he has always been physically active, and he eats a lot of homemade soups loaded with vegetables. His life is a study in a thousand details - details that add up to a life well lived.

Murray gets up. Does his pre-dawn exercise routine. Eats his bowl of oatmeal. Does his chores. 

And then every single day, around noon, he sets off to visit the love of his life: his 88-year-old wife, Helen, who is in a nearby nursing home. He brings her pudding and other homemade treats to boost her spirits. 

"We've had a very good life together," he says. "But I miss her very much."
Ask Murray about the downside of growing old, though, and you won't get much of a list. In fact, Murray is looking forward to the days or years he has left.

Sure, he has some aches and pains. His hearing isn't as good as it once was, and just last month he started to use a cane to walk. 

But he's still walking. He still has his wits about him. He remains close to his six adult children, who range in age from 60 to 68. And he still has a lot of friends.

"Every night and day," he says, "I thank God for my blessings."