We've been bombarded over the years with warnings about all the things we shouldn't do to protect our health and help us live longer, such as smoking, eating the wrong foods, drinking too much alcohol, and so forth.
Now, someone has taken a look at the opposite side of that coin to see whether the positive things we can do can be as important as the negative things we shouldn't do.
And here's what they found: Believing you are in control of your own life, maintaining strong social ties to friends and family, and getting off the couch for vigorous exercise can delay the effects of aging by at least a decade.
So what it all means is what you do today (not just what you shouldn't do) will determine what you are tomorrow. And the research suggests this is probably a lifelong process, so it's never too soon to get started.
Psychologists Margie E. Lachman and Stefan Agrigoroaei of Brandeis University in Boston delved into the Midlife Development in the United States study (MIDUS), a national interagency resource involving 3,626 adults aged 32 to 84 who were interviewed in two sessions about 10 years apart, to see what role positive factors played in their health.
They focused on "what to do rather than what not to do," according to their study published in the current PloS ONE, an open access science journal.
"On average," they reported, "functional health declined significantly over the eight to 10 years, and, as expected, the declines were greatest in later life."
Yet they also found that those who took a more positive approach to life experienced far less decline.
The researchers looked at three main "factors." Strong social ties and physical exercise turned out to be highly effective in delaying the decline, but the keystone is an attitude that psychologists call "control beliefs."
"Beliefs about control include expectancies about the responsiveness of the environment and one's own abilities to negotiate it and bring about desired outcomes," Lachman said via e-mail.
That's a huge factor because if someone doesn't believe that he or she is in control of his or her own destiny, why try to do anything?
Why get off the couch if your genes have already determined that you are going to be fat? Someone who believes in control is likely to recognize that genes play a role in body shapes but don't necessarily have the last word.
But those kinds of beliefs are formed very early in life and are very difficult to change. Someone who is optimistic about life as a child is likely to still be upbeat in later life. Lachman argues though that while such beliefs may be embedded in who we are, they are not impossible to modify.
"Such beliefs are learned through experience and they are more malleable than personality traits," said Lachman, who directs Brandeis' Lifespan Development Psychological Laboratory. "There are individual differences, with some more likely to believe little can be done and others believe they are mostly responsible for what happens."