Exercise may protect brain volume through maintaining insulin metabolism and body mass index. The corresponding study was published in Neurology.
For some time, researchers have been aware of the benefits of exercise for brain health and dementia onset. However, until now, the mechanisms behind these benefits have not been fully understood.
The researchers enrolled 134 participants with an average age of 69 for the study. Each filled out surveys detailing their physical activity levels over the last year. They also underwent brain scans to assess their brain volume and glucose metabolism. The researchers further collected data on their BMI, insulin levels, cholesterol, blood pressure, and other factors.
After analyzing the results, the researchers found that those with the most physical activity had the highest levels of gray matter volume. More physically active people had an average of 550,000 cubic millimeters of gray matter compared to 540,000 in those who exercised less. They found the same results in areas of the brain affected by Alzheimer's disease.
Those who exercised more also had a higher rate of glucose metabolism in the brain than those who exercised less. They noted, however, that rates of exercise were not related to rates of amyloid plaque formation- a biomarker for Alzheimer's disease.
"These results may help us to understand how physical activity affects brain health, which may guide us in developing strategies to prevent or delay age-related decline in memory and thinking skills," said study author Géraldine Poisnel, Ph.D., of Inserm Research Center in Caen, France. "Older adults who are physically active gain cardiovascular benefits, which may result in greater structural brain integrity."
The researchers say that their results suggest that having a lower BMI through exercising more could stave off the disturbed insulin metabolism often seen in aging and thus promote brain health. They caution, however, that further research is needed to make conclusive statements.
Sources: Science Daily, Neurology