Exercise Protects Brain Volume by Keeping BMI Levels Low

A new study explored exercise's role in maintaining insulin and body mass index levels that may help protect brain volume and thus stave off dementia. The research is published in the online issue of the medical journal Neurology.

"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 G�raldine Poisnel, PhD, of Inserm Research Center in Caen, France. "Older adults who are physically active gain cardiovascular benefits, which may result in greater structural brain integrity."

‘Higher physical activity was not associated with how much amyloid plaque people had in their brains. Amyloid plaque is a marker for Alzheimer�s disease.’

In contrast, researchers found that the relationship between exercise and the metabolism of glucose in the brain was not affected by insulin or body mass index (BMI) levels. Reduced glucose metabolism in the brain can be seen in people with dementia.

The study involved 134 people with an average age of 69 who had no memory problems. The people filled out surveys about their physical activity over the past year. They had brain scans to measure volume and glucose metabolism. Information was gathered on BMI and insulin levels as well as cholesterol, blood pressure, and other factors.

` People with the most physical activity had a higher total volume of grey matter in their brains than people with the least amount of physical activity, with an average of about 550,000 cubic millimeters (mm�) compared to about 540,000 mm�. When researchers looked only at areas of the brain affected by Alzheimer's disease, they found the same results.

Those with the most activity also had a higher average rate of glucose metabolism in the brain than those with the least amount of activity.

Poisnel said more research is needed to understand the mechanisms behind these relationships. "Maintaining a lower BMI through physical activity could help prevent disturbed insulin metabolism that is often seen in aging, thus promoting brain health," Poisnel said.

The study does not prove that exercise protects brain volume. It only shows an association.

A limitation of the study is that people reported their own physical activity, so they may not remember it accurately.

The study was supported by the European Union's Horizon 2020 Research and Innovation Program, Region Normandy and MMA Foundation of Entrepreneurs of the Future.

Learn more about brain health at BrainandLife.org, home of the American Academy of Neurology's free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life� on Facebook, Twitter and Instagram. When posting to social media channels about this research, we encourage you to use the hashtags #Neurology and #AANscience.

The American Academy of Neurology (AAN) is the world's largest association of neurologists and neuroscience professionals, with over 38,000 members. The AAN is dedicated to promoting the highest quality of patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer's disease, stroke, migraine, multiple sclerosis, concussion, Parkinson's disease and epilepsy.

Source: Eurekalert