High levels of physical activity may mitigate brain loss in adults and help maintain long-term cognitive health, researchers at UT Southwestern Medical Centre report in a study published in the Journal of Applied Physiology.

Rong Zhang, Ph.D., is Professor of Neurology, Biomedical Engineering, and Internal Medicine at UT Southwestern and an Investigator in the Peter O'Donnell Jr. Brain Institute. He is also Director of the Cerebrovascular Laboratory at the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Dallas.

“Age-related brain atrophy is one of the significant risk factors for Alzheimer’s disease and related dementias (ADRD),” said senior author Rong Zhang, Ph.D., Professor of Neurology, Biomedical Engineering, and Internal Medicine at UT Southwestern and an Investigator in the Peter O’Donnell Jr. Brain Institute. “This study suggests that engaging in activity to improve one’s physical fitness may reduce the risk of ADRD.”

ADRD is a set of debilitating conditions that impair memory, thought processes, and functioning, primarily among older adults. More than 6 million people in the U.S. have ADRD, and the Centres for Disease Control and Prevention projects the potential for nearly 14 million adults in the U.S. to have Alzheimer’s by 2060.

Researchers examined data from 172 sedentary yet healthy adults between the ages of 22 and 81 from the Dallas-Fort Worth area. Each participant underwent a cardiorespiratory fitness (CRF) test, cognitive testing, and MRI scans. Peak oxygen consumption was monitored and used to measure CRF, with higher peak oxygen consumption reflecting better CRF. 

Among participants, researchers found that ageing was associated with smaller grey matter volumes and the thickness of the cerebral cortex.

After controlling for sex, years of education, total intracranial volume, and peak oxygen consumption, statistical analyses also revealed that ageing was associated with lower volume in the right superior parietal area of the brain in those who had lower peak oxygen consumption, but not in those with higher peak oxygen consumption. Notably, the right superior parietal region of the brain plays an important role in fluid cognitive function, and researchers found that a larger right superior parietal volume was linked to better cognitive function, such as inductive reasoning, long-term memory, working memory, and verbal fluency.

The red section of this MRI scan from a participant in the study shows the right superior parietal region of the brain. The researchers found that a larger right superior parietal volume is linked to better cognitive function, including inductive reasoning, long-term memory, working memory, and verbal fluency.

Researchers also found that the weaker relationship between age and right superior parietal volume in the higher peak oxygen consumption group was present in both men and women, which suggests high levels of cardiorespiratory fitness may mitigate deterioration of brain volume and preserve cognitive function in both men and women.

“The findings from this study support the hypothesis that engaging in lifelong physical activity to improve physical fitness may prevent or slow brain ageing and ADRD,” Dr. Zhang said.