Credit: Military Health
Conventional wisdom tells us that exercise can help strengthen all of our muscles — including our brains. Study after study has reinforced this wisdom.
So Dr. Kaycee Sink was understandably surprised when her recent study found no connection between physical activity and cognitive health.
The study, published in the Journal of the American Medical Association, enrolled 1,635 sedentary adults ages 70 to 89 and broke them into two groups: one focusing on physical activity (walking, resistance training, and flexibility) and the other on health education (workshops and upper-extremity stretching).
After two years, the average participant in each group had comparable cognitive test results to the other participants. In fact, 13.2 percent of the physically active group developed mild cognitive impairment (MCI) or dementia over the 24-month period; 12.1 percent of the health education group did.
The result “flies in the face of conventional wisdom,” Dr. Sink, director of the memory assessment clinic at Wake Forest Baptist Medical Center, told Time.com.
But this one study doesn’t necessarily disprove those that found contradictory results. Study authors give several possible explanations for the discrepancy:
- participants were not assigned the right amount of physical activity to show benefits
- cognitive function improved only temporarily before growth was measured
- participants’ education level may have helped prevent cognitive decline
- health education could have been as helpful as physical exercise
“It is possible, likely even, that one of the reasons we didn’t see a difference between our physical activity group and our control group is because both groups benefited from their participation in the trial,” Dr. Sink said. “Physical activity just wasn’t better than attending group-based health education seminars.”
Additionally, the variety of studies’ results reinforce the importance of continued research on cognitive health.
“It may be that we need to keep doing exercise trials until we have a conclusive answer about whether exercise is beneficial to cognition and, if so, in which patients and at what intensity/duration,” Dr. Sink said.
Don’t cancel that gym membership just yet, as physical activity has many other clear benefits, if not for strengthening one’s mental acuity.
“I tell patients that even if I can’t prove to you that exercise is beneficial for your brain/cognition (compared to staying socially and cognitively active), you should still engage in regular physical activity because of its benefits on other aspects of your health,” Dr. Sink said.