Want to age well? Research suggests benefits to trying a new challenge

Among all those feisty boomers are millions of people who will live longer — though not necessarily healthier — than previous generations of Americans did. U.S. life expectancy was 78.5 years in 2009, according to the United Health Foundation's 2012 America's Health Rankings. That's 1.7 years above the level in 2000. The extra years come at a price.

"Because Americans are living longer, we're seeing more problems with cognitive changes in advanced age," Williams said. "After age 85, almost one in two people have some kind of cognitive decline issue."

So why not take steps to avoid those declines by taking a word of advice from Shirley Joel?

“You find a passion,” she said, “maybe one you haven’t been able to develop. You tap different resources maybe you weren’t aware of. One really has to be willing to adventure, be flexible and try new things.”

Joel said she has never forgotten words uttered by one of her interview subjects, a woman who retired from life as a reporter for NBC, then joined the Peace Corps at age 63:

“Retiring? You retire a boat. You retire a debt. You don’t retire a person.”