Mar 19, 2009 (Voice of America News/ContentWorks via COMTEX) -- DATELINE: Washington, D.C.

Living to age 100 and older is no longer a rarity. Centenarians are now the world's fastest growing age group, according to longevity experts. Understanding why and how certain people live so long is key to helping society redefine aging itself, and it offers younger generations some valuable life lessons.

Longevity researchers are trying to find answers to some basic questions such as: Who lives to be 100? Are centenarians different from the rest of us? And is living that long worth it?

"It actually is a wonderful thing to get to 100," says physician and researcher Thomas Perls. He adds many younger people don't understand what living to 100 is really like.

"A lot of people ask, 'Gosh, who would want to live to 100?' because they get this idea of 'the older you get, the sicker you get,' when in fact, what we've found is very opposite to that," he says. "Centenarians, they markedly delay the onset of any kind of disability well to their early- to mid-90s. It's almost as if, if you have any kind of disability, it's much tougher to get to that age. So instead of it being a matter of 'the older you get, the sicker you get,' it's much more of the case, 'the older you get, the healthier you've been,' which is really a very optimistic view of aging."

More people living to see 100

Perls is founder and director of the New England Centenarian Study at Boston University. Since 1992, he says, the study has been analyzing the mental, physical and emotional health of hundreds of centenarians across North America.

"It's the largest study of centenarians in the world," he says. "We have accumulated now about 2,000 subjects that range in age from 100 to 119. The oldest person we've had in our study was the second-oldest ever in the world, which was 119, a lady named Sara Canals in Pennsylvania."

There are about 40,000 centenarians in the United States today. That's due, in part, to 20th-century medical and public health advances, such as the widespread availability of clean drinking water, nationwide vaccination programs, success in reducing maternal and childhood mortality and the discovery of cures for many illnesses.

Healthy habits, positive outlook key to aging gracefully

However, as Perls notes in his book, Living to 100, centenarians have their own secrets that have helped them outlive the rest of their generation.

"While longevity runs very strongly in the families of centenarians, in order to get to your early 90s, however, I'd say getting there, much of it is going to be good health behaviors. Those health behaviors that we've learned from our study include being vegetarian, mostly just avoiding red meat, not smoking, regular exercise that results in you being at a healthy weight.

"[It includes] doing a good job of not so much avoiding stress, rather managing stress so it doesn't get to you. That can be done through your relationships with family, perhaps with meditation or religion. Some people have personalities that are highly conducive to managing the stress. They don't internalize it. They are able to let go."

"The most prominent trait that centenarians have in common is a love of life, which includes a sense of humor," says Lynn Adler, who has been working closely with centenarians for more than two decades.

In 1985, Adler founded the National Centenarian Awareness Project, a non-profit group that celebrates the lives of people who live to be 100. In her book, Centenarians: Bonus Years, she sums up the traits they share, in addition to that love of life.

"Second, a positive, yet realistic attitude," she says."Third is a strong spiritual or religious belief. Fourth is personal courage, because it's not easy growing older, and there are a lot of things that can go wrong.

"And the last - and I think most important [trait] - is a remarkable ability to renegotiate life at every turn and to accept the losses and changes that come with aging and not let it stop them. They've successfully lived their lives through so many changes: the Great Depression, world wars and a lot of the things that we today are going through."

Adler, who also produced a documentary titled Centenarians Tell It Like It Is, says she finds it inspiring that so many centenarians are doing so well.

"It's just outstanding to see so many people living alone or with very little assistance, to see many of them living in perhaps in assisted living facility but in their own apartments. Some people are still driving," she says. "They are doing amazing things, centenarians who are very, very contemporary in their thinking. I mean, they enjoy life. I think we certainly have marvelous positive role models of people who are living cool."

'Golden years' as precious as jewels

One of those role models is 101-year-old Elsa Hoffman, of Florida.

"My golden years are like sparking diamonds," says Hoffman, who is a mother of four, grandmother of nine and great-grandmother of 13 children. Living to 100, she says, has been an exciting experience.

"When I approached 90, I was so thrilled, and I had a big party," she recalls."I also never told my age until I was 90. Then, I had this feeling that that was the [peak] of my life. I kept on to 95, then 100, and no one feels 'I can live that long,' and here I am going into 102. I have as much interest in life as I did when I was 30 or 40."

Hoffman attributes her longevity to her lifestyle. She doesn't smoke. She's always active, and she watches her weight. More importantly, she says, she's always been positive, seeing the glass as half-full.

"Everyone should make the most of those years and not say, 'Oh, I wish I was so and so. I had such a good time.' 'Oh, I'm 70. I'm 80. I'm getting old,'" she says. "That always made me feel, 'How can people think like that?' Every stage of life has its own beauty."

That positive attitude toward life and oneself is part of what makes many centenarians such inspiring role models, says researcher Thomas Perls. The longevity expert adds that another important lesson young people can learn from these remarkable seniors is that healthy lifestyle choices early on in life are the key to living healthierC and living longer.

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