(Getty Images)

MONDAY, June 8, 2009 (Health.com) — Want to keep your wits sharp as the years go by? You’re not alone. Most people are worried about losing their memory as they age, and a new study shows it’s a valid concern: In fact, at 53%, more than half of all people have at least a minor mental decline in their 70s and 80s, and about 16% develop more serious problems with memory and other mental functions as they age.

The good news is that many people don’t experience mental decline, according to a study published in the journal Neurology. About 1 in 3 people in the study breezed through their 70s and into their 80s without any memory problems. What’s more, when the researchers took a close look at this group, whom they call “cognitive maintainers,” they found evidence that although genes or illnesses can increase the risk of memory loss, there are still many things you can do to save your aging brain.

It seems that exercise is key, and mental activity and a vibrant social life can’t hurt, either.

“There are some things that you can definitely take charge of, and not only will they benefit the brain but benefit the rest of your body,” says Jennifer Weuve, MPH, ScD, an assistant professor at the Rush Institute for Healthy Aging, who was not involved in the study. “There seems to be a little bit that may be within our control. It’s not a given that your brain has to go down the tubes.”

Here’s what the research team, led by Alexandra J. Fiocco, PhD, of the University of California, San Francisco, found:

• Stay in school: High school graduates were 2 to 3 times as likely to be cognitive maintainers, compared to those with minor memory loss. Those with a ninth-grade literacy level or higher were 4 to 5 times more likely to maintain their mental capacity with age.
• Quit smoking: Chalk up one more advantage of steering clear of cigarettes. Nonsmokers were 1.84-fold more likely to be in the “no memory loss” category compared with those with minor decline.
• Exercise: People who engaged in moderate or vigorous activity at least once a week were 1.34-fold more likely to be memory maintainers.
• Stay connected: People who lived with someone had a 1.24-fold higher chance of being a memory maintainer, and the same was true for those who did volunteer work.

Fiocco and her colleagues followed 2,509 healthy men and women over an eight-year period. All the study participants were either black or white and in their 70s when the study began.

Next page: Diabetes, genetics can increase risk of mental decline