New research shows that exercise helps protect brain health by maintaining cardiovascular risk factors low.
Previous research had shown that larger gray matter volume can help protect against dementia by improving brain function.
The new study shows that insulin resistance and BMI mediate the relationship between larger and smaller brain gray matter volumes (the part of the brain involved in processing information).
The research is published in the April 2022 online issue of Neurology, the medical journal of the American Academy of Neurology.
The corresponding author of the study was Dr. Geraldine Poisnel, of the Inserm Regional Research Center, in Caen, Normandy, France.
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.