Although physical fitness is important, so is psychological fitness. "The word I like to describe successful aging is active aging," said geriatric psychiatrist Reynolds. "That means socially, intellectually, and spiritually." Research has shown that people who maintain connections to others -- whether through family, friends, or work -- remain healthier in old age. A study of centenarians found that they had a purpose to their lives -- volunteer work or taking care of grandchildren and great-grandchildren.
But these rules aren't universal. "Everyone ages differently," the National Institute on Aging's Bernard pointed out. "If people who have been lonely and isolated their whole lives, and we say they need to be out and socializing -- but it's not in their nature -- it could be more stress than benefit."
She touts the advantage of preventive care as a larger part of the U.S. medical system, noting studies that show a greater incidence of cancer, heart attacks, strokes, diabetes, and lung disease in older Americans compared with Europeans. Preventive care can even ease depression, a serious problem among the elderly, albeit one that medical professionals often dismiss as natural and not worth treating. Not so, according to Reynolds. Depression can be treated with medication or psychotherapy, thereby improving a patient's physical health. The benefits -- and the downsides -- flow in both directions. "Disability can beget depression," Reynolds said, "and depression can beget disability."
But depression should be distinguished from garden-variety worrying -- and here's a provocative finding: People who fret about things may live longer. "[A] moderate amount of worrying can be good," particularly for men, said Leslie Martin, a psychology professor at La Sierra University in Riverside, California. Research has shown that men who think ahead and plan -- and, yes, worry -- tend to fare better after their wives die. In fact, men who were worriers faced a 50 percent lower risk of dying within the next few years after becoming widowers than men who weren't worriers, Martin reported.
Possibly the reason is that, in many marriages, "the wife is the protector -- telling the husband to get the doctor's checkup, to eat healthier, to wear a seat belt," she explained. "If a guy does more on his own, it may serve him well." This could also explain why men who are happily married tend to live longer than men who aren't, while wedded bliss seems to have no effect on women's longevity.
But for children, surprisingly, happiness can be a curse. Cheerful and optimistic kids lead shorter lives, Martin said. That's often because they participate in riskier hobbies and sports, and are more likely to smoke and to drink too much. "They think, 'Nothing bad will ever happen to me,' " she said.
It's good news, then, that whether people -- even teenagers -- will age with grace lies in many ways within their control. Of course, one always has the chance of getting hit by a truck. The role of dumb luck inspires experts to counsel: Don't be too hard on yourself. As federal administrator Bernard put it, "People shouldn't blame themselves if their aging isn't going exactly as they want."
Hey, relax (but not too much). Maybe you'll live longer.