In addition to exercise and good nutrition for the aging brain, using the computer to keep your mind active could prevent mild cognitive impairment (MCI). This form of cognitive decline falls in between normal age-related memory problems and the beginnings of Alzheimer's disease.

It turns out that both exercise and computer use each have protective effects -- but the two together are even better.

Researchers at the Mayo Clinic studied 926 people in Minnesota between the ages of 70 and 93. They had them fill out questionnaires about the kinds of physical activities they engaged in, including aerobics, strength training, yoga, hiking, swimming, and others. They also asked the participants about how often they took part in mentally stimulating activities, like playing games, reading, play music, arts and crafts, and using the computer. The team was particularly interested in computer use, given its prevalence across all generations.

It turns out that both exercise and computer use each have protective effects -- but the two together are even better. Of the people who neither exercised nor used a computer, about 20 percent had normal cognition, and almost 37 percent had mild cognitive impairment. But people who used computers and exercised regularly were in much better shape: 36 percent were cognitively normal, while only 18 percent had MCI.

"The aging of baby boomers is projected to lead to dramatic increases in the prevalence of dementia," study author Yonas Geda said in a news release. "As frequent computer use has become increasingly common among all age groups, it is important to examine how it relates to aging and dementia. Our study further adds to this discussion."

The study does not actually show cause and effect -- there could be another variable at play -- but it does hint at the idea that keeping cognitively active might somehow protect the brain, as earlier studies have also suggested. Exercise has been shown time and time again to reduce the risk for cognitive decline and even help reverse symptoms once they start. Keeping the brain engaged whether on the computer or off it also can't be a bad activity to get into.

The study was carried out by a team at the Mayo Clinic, and published in the Mayo Clinic Proceedings.