Exercising has been shown in studies to help protect brain cells. A new study looking into the mechanisms involved in this relationship suggests that the role exercise plays in maintaining insulin and BMI levels may help protect brain volume and thus help prevent dementia.
They will be in the online edition of Neurology, the journal of the American Academy of Neurology, on April 13, 2022.
“These findings may help us 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 Géraldine Poisnel, Ph.D., of the Inserm Research Center in Caen, France.
Physically active older people may have better cardiovascular health, which could lead to better brain structure.
In contrast, researchers discovered that insulin and body mass index (BMI) levels had no effect on the relationship between exercise and glucose metabolism in the brain. Patients with dementia have decreased glucose metabolism in the brain.
The study included 134 people with no memory problems and an average age of 69. People completed surveys about their physical activity over the previous year. They underwent brain scans to determine volume and glucose metabolism. All were collected: BMI insulin levels, as well as cholesterol, blood pressure, and other factors.
People who engaged in the most physical activity had a greater total volume of gray matter in their brains than those who engaged in the least amount of physical activity, with an average of approximately 550,000 cubic millimeters (mm3) compared to approximately 540,000 mm3. The same results were found when researchers only looked at areas of the brain affected by Alzheimer’s disease.
Those who were the most active also had a higher average rate of glucose metabolism in the brain than those who were the least active.
Higher levels of physical activity were not related to the amount of amyloid plaque in people’s brains. Amyloid plaque is an indicator of Alzheimer’s disease.
More research, according to Poisnel, is needed to understand the mechanisms underlying these relationships. Maintaining a lower BMI through physical activity may help prevent the disturbed insulin metabolism that is common in aging, thus promoting brain health, “Poisnel explained.
The study does not prove that physical activity protects brain volume. It only demonstrates an association.
One problem with the study is that the people who took part in it reported their own physical activity, and they may not have been able to remember it correctly.