STEVE INSKEEP, HOST:
OK, not everybody can be a super-ager. But many brain researchers agree that declines in memory are not necessarily inevitable. As NPR's Patti Neighmond reports, there are things we can do to keep dementia at bay.
PATTI NEIGHMOND, BYLINE: You may be surprised to hear that the best thing you can probably do for your brain is exercise your body. Neuroscientist Art Kramer, with the University of Illinois, has studied the impact of aerobic exercise.
ART KRAMER: Walking, jogging, swimming, aerobic exercise in the pool, or riding your bike.
NEIGHMOND: In Kramer's study, participants had brain scans before and after they started a program of moderate aerobic exercise - just 45 minutes, three days a week; mostly walking. After a year, Kramer found the volume of their brains actually increased. And that translated into a better memory. Kramer points to earlier research that found significant changes in the brains of rodents when they exercised.
KRAMER: It increases the number of new neurons, the computational factories in the brain; it increases the effectiveness of connections between different brain regions; and also increases the blood supply to various regions of the brain.
NEIGHMOND: So one more reason to get up and get moving. And while the evidence isn't nearly as conclusive when it comes to mental exercise, keeping your brain active can't hurt, says Kramer. Take his 93-year-old aunt, Angela Little, a retired science professor at the University of California, Berkeley. She's currently taking a course in Italian literature.
ANGELA LITTLE: We read Dante, we read "The Inferno," we read Boccaccio.
NEIGHMOND: It's a two-hour class involving discussion and historical analysis. I ask if it's taught in English.
LITTLE: Oh, no, no, no, no. Everything is in Italian. We don't speak English at all; everything is in Italian, absolutely - assolutamente.
NEIGHMOND: It's learning new things that seems to offer the biggest benefit. So new novels are good. If you do crossword puzzles, try shifting to Suduko - a puzzle that uses numbers. Learn a new language. Play a new instrument. The brain likes novelty, says Kramer, whose aunt enjoys another important activity - socializing.
LITTLE: I've outlived my generation - this is true - but I've inherited the children of my departed friends, and they're now my friends. And we go to lunch together, go to museums together, or just sit around and chit-chat or play Scrabble, or something like that.
NEIGHMOND: Studies have shown that just the act of getting together with friends may help stimulate the brain. Bryan James is an epidemiologist at the Rush Alzheimer's Disease Center in Chicago. He recently looked at the social lives of about 1,100 adults over 80.
BRYAN JAMES: So we asked people about going to restaurants, going to sporting events, playing bingo and other social games like that; doing unpaid community and volunteer work, going on day trips.
NEIGHMOND: Individuals were followed for up to 12 years. Those with busy social lives were half as likely to develop dementia, compared to those who weren't socially active. In another study, Adams looked at something he calls life space. [POST-BROADCAST CORRECTION: The epidemiologist's last name was misstated. It is James.] He added up how often people literally got out of their bedroom, went out of their house, traveled out of their neighborhood or out of town.
JAMES: The people who never left their home - even though they didn't seem to have any cognitive problems, when we started following them - were twice as likely to develop Alzheimer's disease over that five-year time period.
NEIGHMOND: And finally, the notion of brain food. Some evidence suggests that omega-3 fatty acids, found in fish; and antioxidants, found in vegetables and red wine; may help nourish the brain - leading neuroscientist Art Kramer to suggest this...
KRAMER: The walking book group with good red wine: You walk; you talk about something stimulating - a book that you've read - with good friends. How can you beat it? It's got all four.
NEIGHMOND: Good food, social activity, intellectual challenge and most important of all, physical exercise.
Patti Neighmond, NPR News.
(SOUNDBITE OF MUSIC)