To Keep Your Smarts, Exercise More than Just Your Brain


by Guy McKhann, M.D.

June 26, 2007

Why do some people, as they age, “keep their smarts”—that is, they maintain their cognitive functions well—and others do not? A number of longitudinal studies indicate that the successful agers share four traits:

  • They are more mentally active.
  • They are more physically active.
  • They maintain a sense of their social engagement. In other words, they see themselves as still having roles to play in life—in their families, communities, or even in continuing employment.
  • They pay attention to controlling the risk factors for disease of the heart and brain. They may stop smoking, control their blood pressure, keep cholesterol within normal limits by diet or medications, and/or recognize and treat diabetes.

Moreover, it appears that these factors reinforce one another: the more of them people follow, the better.

As regards physical activity, successful agers are not trying to make the Olympics; they are getting exercise by using stairs, walking significant distances, swimming or participating in exercise groups. The important thing is that they are exercising on a regular basis, as part of their weekly routines.

Being mentally active takes many forms: doing crossword puzzles, playing cards, reading, going to lectures, whatever study participants enjoyed. What they were not doing was sitting around, passively watching TV.

This brings me to the possible roles of brain training programs.

This is not a new topic. Ten years ago Larry Katz and Manning Rubin at Duke introduced the concept of “neurobics”—mental exercises designed to maintain or improve memory functions. They were not alone; there has been a proliferation of books, games and exercises that claim to achieve the same goal.

What has been added in the most recent incarnations of memory training are three things: the use of computers in training; outcome measures besides changes in cognitive performance, such as imaging the blood flow to parts of the brain; and a greater emphasis on claims of a neuroscientific basis for particular approaches.

This is a valid area of brain research; there are many questions to be answered. Can specific mental exercises maintain brain functions? Can they restore lost functions?

At what age should people use these programs? Is it possible to devise a program that fits all subjects, or should there be variations based on age, culture and education?

How will we measure success—only in the specific area of training or in other cognitive domains as well? If there are gains, do they stick around or are remedial sessions needed?

Perhaps the most important question, in evaluating these programs, is: improvement compared to what? Are these newer approaches better than regularly doing crossword puzzles or struggling with Sudoku?

Many, perhaps millions, of people older than 40 or 50 have great interest in this area. Consequently, “there is gold in them thar hills,” as the saying goes, particularly with computer programs selling at $300 to $400 a pop.

Some neuroscientists are skeptical and feel that this rush to commercialization is premature. I am in that camp. My advice remains that maintaining mental activity is important, but there is no standard formula for doing that. Challenge your brain by doing whatever turns you on—just do it!

Also, don’t be too monolithic in your approach to maintaining brain health. As mentioned above, the behaviors of successful agers are reinforcing. Focusing only on mental training to the exclusion of the other measures is not the correct thing to do. Being physically active, involved with others, and keeping your blood pressure under control may be just as important as trying the latest memory game.

Guy McKhann, M.D., is professor of neurology and neuroscience at the Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore. He serves as scientific consultant for the Dana Foundation and scientific advisor for Brain in the News.