Study: Exercise Helps Keep Seniors Sharp

Regular, moderate exercise can increase the amount of brain tissue in the elderly and help keep their minds in good shape, a new study shows.

It was the first time researchers showed that exercise can increase brain mass, according to Early Show medical contributor Dr. Mallika Marshall.

She says the researchers think increased blood flow to the brain during exercise is at work.

Marshall told co-anchor Hannah Storm: "This was a study out of the University of Illinois at Urbana and published in this month's Journal of Gerontology, and was the first study to show that we can actually increase brain tissue as we age by doing something as simple as exercise."

She called that a "big" and "pleasant" surprise.

"As we get older," Marshall said, "we have more and more difficulty processing information. It takes us longer. For example, someone in their 20s, it may take a couple of seconds to remember a name from their past, but for someone who's older, it can take a lot longer. We also have more problems with multitasking. This study shows that simply by exercising, we can actually increase the amount of brain tissue we have."

Marshall said the researchers "looked at people between the ages of 60 and 80 and found those who exercise regularly had an increased number of neurons, or brain cells, particularly in their frontal lobes, which are really important for higher order thinking, things such as memory and attention. They also increased number of connections in the corpus callosum, which is really important for enabling the right side of the brain to communicate with the left side of the brain. And they think this was all due to increased blood flow to the brain while exercising."

She pointed out the amount of exercise involved wasn't all that much: "The study participants were asked to exercise an hour a day, three times a week, at a moderate pace. That's not to say, if you did more strenuous exercise that you might not enjoy a greater benefit, but they did show that moderate exercise can actually increase brain tissue."

Marshall stressed that, "The big surprise, which was a pleasant surprise, was that you can increase the number of neurons in your brain as you get older. That was thought to be impossible. What's not surprising is exercise has positive effects on the brain; previous studies have shown that."

The study didn't address whether exercise can slow the onset of Alzheimer's disease or dementia.

"The study participants didn't have Alzheimer's," Marshall said. "They didn't have dementia. But previous studies have suggested that regular exercise can help ward off dementia."

She noted that earlier studies have also shown that mental exercise, such as doing crossword puzzles or reading newspapers, can sharpen your mind and keep your brain healthy, thought his study didn't cover that, either.