In part one of this two-part series, we looked at pills and potions that promise to sharpen memory. In part two, we show why exercising your mind and body not only boosts memory but helps you think fast.
At Baylor College of Medicine, neurologist John Stirling Meyer is too busy to worry about whether his memory is as sharp as it once was.
At 73, Meyer directs a major research laboratory for cerebrovascular research, treats patients, and supervises scientific studies that involve more than 15,000 volunteers. When he's not writing groundbreaking scientific studies, he's swimming at the university pool or playing a round or two of golf. That whirl of activity, Meyer believes, is the single best prescription around for a sharp and healthy mind.
"People say, 'Use it or lose it' about the body," says Meyer. "The same advice goes for the brain." More and more research, in fact, shows that a combination of mental and physical activities can protect your memory and help keep you alert.
Physically Fit, Mentally Agile
Researchers have long known that the brain's processing speed gradually slows as we age. Between ages 25 and 55, we're likely to lose about 25% of our synapses, the connections that relay messages from neuron to neuron.
"With age, many people begin to experience problems coming up with names or numbers," says Meyer. "The memory is there. It just takes people longer to retrieve it."
Staying physically fit can ward off at least some of the effects of age on the brain. In the May 1990 issue of Neurobiology and Aging, neurobiologist Robert Dustman showed that aerobically fit people had steeper peaks and valleys in brain waves associated with alertness, a sign that they were better able to tune out distractions and focus their attention. In real life, that could mean coming up with a forgotten name more quickly or jumping out of danger in the face of an oncoming car.
The two factors that best predict an older person's performance on tests of information processing are physical ones, says Waneen Spirduso, director of the Institute of Gerontology at the University of Texas at Austin. The number of years the person exercised and the person's current aerobic capacity seem to matter most.
Why should aerobic fitness matter to the brain? Exercise keeps the heart strong and blood vessels open, which in turn ensures that brain cells get all the nutrients they need for peak performance. That's critically important to brain function.
Although neurons make up only 2% of total body weight, they use one quarter of all the glucose and oxygen the body takes in. A vigorous workout also triggers parts of the brain related to movement and balance, which can keep neuron connections strong.
Challenging the Brain
But other research suggests that mental gymnastics are as important as physical ones to preserving brainpower. To prove it, for three years Meyer followed 90 people who had just reached retirement. In the February 1990 Journal of the American Geriatric Society, he reported that blood flow in the brain had significantly declined in people who retired to their easy chairs. Among those who kept working or pursued new interests, cerebral blood flow remained strong and healthy.
Other recent experiments have suggested that -- contrary to what biologists have long believed -- brain cells can reproduce. But can mental exercise make it happen? Perhaps. In the July 1998 issue of Neuroscience, researchers reported that when rats were required to learn their way around a complicated water maze, parts of their brains associated with memory churned out a type of chemical that makes cells multiply.
What's the best way to keep your mind engaged? Robert Goldman, MD, author of Brain Fitness, thinks that tackling unfamiliar tasks or new ways of thinking can help develop underused brain connections. Among his suggestions:
- Take up word games like crossword puzzles and acrostics.
- Memorize favorite poems or famous passages like the Gettysburg Address.
- Read challenging books or articles that encourage you to expand your interests.
- Practice other-handedness. If you're right-handed, try brushing your teeth or writing your grocery list with your left hand.
But you don't have to resort to parlor tricks to keep your brain exercised. Meyer is convinced that any activity that requires you to think and concentrate -- from keeping a journal or learning a new language to taking music lessons -- will challenge your brain. And your brain will thrive on the challenge.