Photo by Ussama Azam on Unsplash
Increasing physical activity is one of the best-known ways to preserve cognitive function as we age. Exercise beefs up critical brain regions and increases blood flow. A new study suggests exercise may afford similar benefits to adolescents, too. Scientists at the University of Oxford found active and physically fit kids have healthier brains than their more sedentary peers.
The findings “highlight adolescence as a key time to encourage healthy, active lifestyles not only to optimize physical health but also to boost brain health,” said Heidi Johansen-Berg, senior author of the study, during a press conference at the Society for Neuroscience’s Global Connectome conference on January 12. The study appears in the January 12 issue of JNeurosci.
Adolescence marks a critical period in brain development. The brain’s information highways — thick bundles of insulated nerve fibers — bulk up, enhancing communication between different brain regions. Weak connections between brain cells are pruned away. But all these changes present a double-edged sword: teens are more vulnerable to mental health conditions like depression, anxiety, and addiction.
Exercise may support healthy brain development during this critical window, yet studies show today’s teens lead more sedentary lives than past generations. Worldwide, only one in five adolescents meets the recommended guidelines of 60 minutes of exercise per day. Some experts fault the rapid expansion of digital devices.
Johansen-Berg and her colleagues scanned the brains of 50 12-year-olds and tracked their physical activity for a week with wrist-worn accelerometers. They also measured markers of physical health like cardiorespiratory fitness, blood pressure, and body mass index. The brain scans measured multiple aspects of brain health like the size of various regions, strength of neural connections, blood flow, and activity.
In almost every aspect adolescents who were more active and physically healthy had traits associated with healthier brains: larger gray matter, thicker cerebral cortices, stronger white matter connections, and enhanced blood flow.
“Our results suggest that physical activity and aerobic exercise have a much more widespread effect on brain processes than we previously thought,” Johansen-Berg said.
The study is interesting because it “was able to link multiple dimensions of the brain to multiple dimensions of physical health,” said Damien Fair, director of the Masonic Institute for the Developing Brain at the University of Minnesota who was not involved in the research. Repeating the study with a larger sample size would lend further weight to the findings, he said.