The variations in blood sugar values may affect the memory of the patient.This occurs by affecting the dentate gyrus in the brain, which is important in retaining memories.

Researchers said the effects can be seen even when levels of blood sugar, or glucose, are only moderately elevated, a finding that may help explain normal age-related cognitive decline, since glucose regulation worsens with age.

Since glucose regulation is linked with physical activity, regular exercise reduces blood sugar levels and helps improve the memory. Hence there is a direct link between exercis and memory.

In the study, researchers used high-resolution functional magnetic resonance imaging to map brain regions in 240 elderly subjects. They found a correlation between elevated blood glucose levels and reduced cerebral blood volume, or blood flow, in the dentate gyrus, an indication of reduced metabolic activity and function in that region of the brain.

The study was conducted by researchers at Columbia University Medical Center.

source:nytimes