Scholar Sheds New Light on Link Between Exercise and Cognitive Function

    • February 11, 2010

New research shows that even people ages 70 and older can protect brain function with a brisk walk, leisurely bike ride or afternoon swim. Harold Amos Medical Faculty Development Scholar 2008-2012, Yonas E. Geda, M. D., M.Sc., was well-versed in research showing that exercise is associated with a decreased risk of dementia, so he decided to find out if physical activity might also decrease the risk of mild cognitive impairment ( MCI). People with MCI experience very serious problems with memory of recent events, but it is not considered dementia.

“Overall, we know that physical exercise is linked with brain health,” Geda said. “Our finding was that moderate physical exercise--practiced five to six times a week--was most protective against the risk of MCI.” While the study also found that working out in midlife could benefit the brain, the real bonus was the discovery that people who were elderly (ages 70 to 90) and often unable to participate in vigorous activity could protect their cognitive abilities as well.

“Sometimes people who are elderly feel down and depressed, especially if they are only able to move slowly,” said Geda, a professor of psychiatry at the Mayo Clinic in Minnesota. “They think they cannot exercise enough to make a difference, but our work shows that engaging in a simple exercise, such as walking, even late in life can decrease the risk of developing MCI. If a person can only move slowly, they should not feel discouraged. Stay on the bandwagon, there is a benefit.”

Geda cautioned that his work should not comfort couch potatoes. “I want to emphasize that we cannot conclude from this that vigorous exercise is not good for preventing cognitive decline. In a study of younger people, I’m sure vigorous activity would also show good results,” he said. “This study population was over age 70. We did not expect them to engage in exercise such as mountain biking, therefore, we may not have adequate statistical data to examine the question of vigorous exercise and MCI in the younger group.”

While the study did not determine the exact connection between exercise and brain health, Geda speculated that exercise may benefit the brain because it increases the body’s production of a chemical called BDNF (Brain-Derived Neurotrophic Factor). “BDNF nourishes nerve cells that are involved in memory activities,” Geda said.

Geda noted that the study showed that exercise is associated with a decreased risk of MCI, but he stopped short of saying it established a cause and effect relationship. “For that, we would need a clinical trial,” he said, “though our findings are consistent with previous research.”

“Working as a Harold Amos Faculty Development Scholar gave me the time to collect, draft and analyze the data that made it possible for me to add to the science we have on this subject,” Geda added. But around his office, he noticed a more immediate result. “A number of my colleagues said that reading the study encouraged them to go to the gym.”

The study, “Physical Exercise and Mild Cognitive Impairment,” was originally presented at the American Academy of Neurology’s Annual Meeting in 2009 and published in the Archives of Neurology in January 2010.

The Robert Wood Johnson Foundation's Harold Amos Medical Faculty Development Scholar Program provides research awards to physicians from historically disadvantaged groups who are committed to improving the health of underserved populations and to furthering the understanding and elimination of health disparities.