Most people believe that social activities and mental exercise, such as pursuing hobbies or doing puzzles, keep you mentally sharp as you age. Now, British scientists have found that physical exercise slows the rate of cognitive decline by preventing shrinkage of the brain and loss of the white matter wiring in the brain.
"Our results show that regularly exercising in old age is potentially important to protecting the brain as we age," Alan Gow, corresponding author of the study, told TheDoctorWillSeeYouNow in an email.
People who participated in more physical activity experienced less brain shrinkage than those who exercised very little.
"It was not surprising to us that physical exercise was more beneficial [than leisure and social activities] in terms of the structural health of the brain," said Gow. He explained that the results were not surprising because he and his colleagues had found earlier that physical activity improved cognitive ability (thinking and memory), whereas other leisure activities did not, once factors such as level of education and socioeconomic background were considered.
The researchers looked at medical records of the Lothian Birth Cohort 1936, a group of 638 people from Scotland born in 1936. The scientists looked at the association between self-reported leisure and physical activity at the age of 70 and brain structure, as seen on an MRI, at the age of 73.
Study participants gave details about their exercise habits, from only performing necessary household chores to getting regular exercise or participating in competitive sports several times per week. They also reported their participation in social and mentally stimulating activities.
The study found that after three years, people who participated in more physical activity experienced less brain shrinkage than those who exercised very little.
In the Lothian Birth Cohort 1936 study, scientists are examining age-related changes in thinking and memory skills, and trying to identify the genetic and environmental factors that predict these changes, said Gow, a professor of psychology at the University of Edinburgh in Scotland. Study participants undergo periodic MRI scans of their brains, so that the investigators can examine how the structure of the brain changes with age, and how these changes may relate to any changes in cognitive skills.
The current study was published in the journal, Neurology.