The finding comes from a five-year study of more than 2,800 Americans aged 65 to 94.
Researchers at six U.S. institutions gave these seniors a brief series of "cognitive training" sessions. The training was short — just 10 one-hour sessions for most participants, with eight booster sessions for some. But the benefits lasted at least five years, says study researcher Michael Marsiske, Ph.D., of the University of Florida.
"If you have any concerns you cannot learn new things late in life, put those away," Marsiske tells WebMD. "If people put effort into learning new and challenging things after age 65, they can grow in performance. And they can maintain those gains."
It's an elegantly designed study, says Sally A. Shumaker, Ph.D., professor of public health science and associate dean of research at Wake Forest University, Winston-Salem, N.C., who was not involved in the study. Her editorial accompanies the report from Marsiske and colleagues in the Dec. 20 issue of The Journal of the American Medical Association.
"The general note here is that we need to stay mentally active, just as we need to stay physically active," Shumaker tells WebMD. "I can imagine a time when, in public libraries and senior centers, there will be computers you can sit at and do this training every other day or so and slow the process of normal cognitive aging."
Marsiske and colleagues randomly divided the seniors into four groups. One group got 10 memory training sessions. Another group got reasoning skill training. A third group got mental speed training. And a fourth group got no training at all for comparison.
In addition, some of the people in each training group got booster sessions 11 and 35 months after their initial training. During memory training, seniors learned four strategies to help them remember better:
During reasoning training, seniors learned to analyze new material and reach a conclusion about it. For example, a training task might be to analyze a series of letters —A,L,B,A,M,B,A, for instance—and predict the next letter. By regrouping the series into triplets — A,L,B and A,M,B and A ... — it becomes clear that the letter between "A" and "B" is advancing alphabetically. So the next letter must be "N."
During processing training, seniors sat at computer screens that flashed an image at them. As training advanced, the image became more and more complex. This trained the person to take in more and more information at a single glance — a skill necessary for real-life tasks such as driving.
The researchers found that seniors who underwent each type of training reported less difficulty in performing their day-to-day tasks. This finding was significant only for those who got reasoning training, but the effect size (about 70 percent less difficulty in daily living tasks) was similar in the other groups.
However, when independent observers tested the seniors on their ability to perform tasks, they found that only those who got booster sessions did better than untrained seniors did.
Marsiske says this means there's more to daily living than mental ability.
"Cognition is important, but it is not all you need," he says. "Take food preparation, for example. Can I find the food, plan the recipe, and lay out utensils? That's cognition. But there are also things like dealing with a spouse who may not want dinner cooked that night. So cognition is not the only thing that is important."
Exactly what should seniors do to keep their minds sharp? Marsiske and Shumaker agree that more study is needed to learn exactly what training is best, and how often seniors should do it.
But the study shows doing something is better than doing nothing.
"Older adults, people 65 and older, can actually experience new learning," Marsiske says. "Those gains are not overnight successes that go away the next day. We see benefits five years later."
"Certainly reading or doing brain teasers is not going to do harm — and has a good chance of giving lasting benefit," Shumaker says. "If we challenge our minds — play crossword puzzles or Scrabble, for example — this study now shows that it does in fact improve memory and that this improvement can be sustained."
SOURCES: Willis, S. The Journal of the American Medical Association, Dec. 20, 2006; Vol. 296: pp. 2805-2814. Shumaker, S. The Journal of the American Medical Association, Dec. 20, 2006; Vol. 296: pp. 2852-2854. Michael Marsiske, Ph.D., associate professor and associate chairman, clinical and health psychology, University of Florida, Gainesville. Sally A. Shumaker, Ph.D., professor of public health science and associate dean of research, Wake Forest University, Winston-Salem, N.C.
By Daniel DeNoon
Reviewed by Louise Chang, M.D