The study involved 134 people with an average age of 69 who had no memory problems. The participants filled out a physical activity survey covering the past 12 months. They also had brain scans to measure glucose metabolism and brain volume.

The metabolism of glucose in the brain provides fuel for the brain by generating adenosine 5′-triphosphate (ATP) — a key molecule for maintaining the health of neurons and other cells. ATP is also key for generating neurotransmitters. Reduced glucose metabolism in the brain can be seen in people with dementia.

Gray matter development peaks at age 2–3 years. It begins to decrease afterward in some areas of the brain, but the density of the gray matter increases. From an evolutionary perspective, the higher processing ability of the human brain and its development are due to this increase in density.

In some studies, larger total brain volume, estimated by magnetic resonance imaging (MRI), has a weak correlation with higher intelligence in men and a very weak correlation in women with the ability to do well in intelligence tests.

In contrast, brain tissue deterioration and loss of volume is a significant contributor to lower cognitive ability later in life.

In the new study, researchers included 134 people with an average age of 69 who had no memory problems. The participants filled out a physical activity survey covering the past 12 months. They also had brain scans to measure glucose metabolism and brain volume.

In the new study, researchers gathered formation on cardiovascular risk factors including BMI and insulin levels, as well as cholesterol, blood pressure, and other factors.

The researchers examined the relationship between insulin and cardiovascular disease. The metabolic abnormalities that insulin causes raise the risk of cardiovascular complications, which in turn affect brain function.

Researchers found that insulin and BMI levels did not affect the metabolism of glucose in the brain.

The research demonstrated that the amount of amyloid plaque in the brain that contributes to Alzheimer’s Disease was not affected by exercise.

Medical News Today contacted Dr. Raeanne Moore, associate adjunct professor of psychiatry at UCSD in La Jolla, CA.

Dr. Moore, who was not involved in the study, was asked about the study results. She shared with MNT:

“This study adds to the growing body of research on the positive benefits of staying active on brain health, especially as we age.”

“[T]here is an urgent need to identify markers of cognitive decline,” added Dr. Moore. “Decreasing insulin levels and losing weight are modifiable factors that can be improved with a healthy diet and exercise.”

She added, “It was not surprising that higher physical activity was not associated with how much amyloid plaque people had in their brains. There is growing evidence that vascular risk factors on cognitive function are mediated by the amount of tau pathology in the brain and not an amyloid burden.”

MNT also spoke with Dr. Sheldon Zablow, assistant professor of medicine at University of California San Diego Medical School in La Jolla, CA. Dr. Zablow shared his comments about this study:

“Exercise has often been called food for the brain with many studies showing the benefit of exercise for improving brain health and reducing the risk of dementia.”

“This current research study states that physical activity improves cognitive brain function by reducing BMI and improving insulin metabolism. Improvement in weight control can limit the rate of brain volume loss, a known risk factor for dementia.”

“This study will help physicians reinforce the importance of regular exercise in reducing BMI as a low-cost means of limiting cognitive decline.”

– Dr. Zablow