"The amount of memory improvement was equivalent to going back 10 years in your ability," says Elizabeth Zelinski, professor of gerontology and psychology at USC and a principal investigator on the study, which has not yet been published.
Experts caution that most brain-training products haven't been tested and that what data do exist are still shaky. If improvement of daily living tasks is the goal, "we don't yet have the data to suggest they accomplish that," says Arthur Kramer, a neuroscientist at the University of Illinois. "Yes, we have data that says you can get better at certain things with practice. But does it translate to the real world? We don't know yet." Still, many doctors who work with older people feel they don't have time to wait for the research, and nursing homes and senior centers across the country are adding "brain gyms" and other programs to help older people stay mentally active.
"I've learned more about China than you can imagine," says Hortense Gutmann, 100, who started using E-mail just over a year ago through a new computer-education program for residents of Sarah Neuman Center for Healthcare and Rehabilitation, a nursing home in Mamaroneck, N.Y. She now keeps in touch with relatives there, as well as in Minnesota and Israel, and takes great pleasure in having mastered a new skill.
Consumers aren't waiting for more research, either. The market for products like Brain Fitness Program, Nintendo's Brain Age, and MindFit soared to an estimated $80 million in 2007, up from just $2 million to $4 million in 2005, according to SharpBrains.com, a San Francisco-based group that follows the industry. Meanwhile, the Alzheimer's Association recommends any activity that will keep you curious and learning: reading and writing, attending lectures, taking classes, even gardening.
Sound body, sound mind. Still, the best workout for your brain may be the old-fashioned kind.
As far back as 1999, researchers at the University of Illinois found that older people who started exercising showed faster reaction times and better ability to focus after just six months than did a control group. Now, it's becoming clearer why. In a second study reported in 2006, the same team found that the aerobic exercisers actually increased their brain size by about 3 percent. Last year, researchers at Columbia University found that when people exercised regularly for three months, blood flow increased to a part of the hippocampus, which is important for memory. In studies of mice who exercised on treadmills, increased blood flow to the same part of the brain corresponded with an increase in the production of new brain cells.
The power of exercise seems far more impressive than that of brain-training software, says Sandra Aamodt, editor in chief of Nature Neuroscience, a scientific journal on brain research, and coauthor of the forthcoming book Welcome to Your Brain. A recent meta-analysis of numerous exercise studies found that, on average, faithful aerobic exercise might boost someone's cognitive performance from average—say, from 10th place out of 20 people tested—to notably above average—say, to No. 5. But cognitive training would boost the same person to eighth out of 20.
Why is exercise so good for the brain? Maybe for the same reason it's so good for the heart: its beneficial effect on blood vessels. "It may be that a pretty significant amount of deterioration in brain function relates to disruptions of the cardiovascular system by microstrokes," in the tiny vessels in the brain, says Aamodt. Exercise may help prevent them. It also stimulates the production of proteins called growth factors, which promote the formation and growth of brain cells and synapses.