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.
Certain nutrients, too, are thought to be protective. The antioxidants in fruits and vegetables have been linked to improved cognitive function; berries, for instance, seem especially beneficial in keeping brains spry. "Old neurons, like a lot of old married couples, don't talk to each other anymore," says James Joseph, director of the neuroscience lab at the USDA Human Nutrition Research Center on Aging at Tufts University. "We have found that the berry fruits improve neuronal communication." In November, Harvard researchers announced that men who took a beta carotene supplement for 18 years had slightly better cognitive function than those who didn't—their memory scores matched those of people about one year younger. However, men who took supplements for only one year showed no improvement, and several other studies have found no link between antioxidants and mental performance. The Alzheimer's Association recommends a diet high in dark-colored veggies, like kale, spinach, beets, and eggplant; colorful fruits like berries, raisins, prunes, oranges, and red grapes; plus fish like salmon or trout high in heart-healthful omega-3 fatty acids.
Making connections. It has been more than two decades since Bill Harves, 90, quit singing in his church choir. Four years ago, he joined the professionally led chorale that rehearses once a week at his Bailey's Crossroads, Va., continuing care retirement community. The chorale gives several concerts a year, including one at Washington, D.C.'s Kennedy Center. He's gained in breathing technique, enunciation, and music reading skills. "There's no doubt I've improved as a singer," he says.