Higher brain glucose linked to lower gray matter volume
Scans of 47 healthy adults aged 22 to 77 linked fasting brain glucose, but not blood glucose, to lower gray matter volume.
Limit: Only 47 healthy adults were studied, limiting precision of the glucose–volume association
Edited by Boris Djordjevic · AgingResearch.News
In a cross-sectional observational study, 47 healthy adults aged 22 to 77 underwent brain scans after fasting for at least eight hours. Researchers measured glucose in the posterior cingulate cortex, a region toward the back of the brain. They also measured gray matter volume—the amount of tissue rich in nerve-cell bodies—and fasting blood glucose.
Higher brain glucose was linked to lower total gray matter volume after accounting for age, body mass index—a measure of weight relative to height—and blood glucose. Blood glucose showed no such link. A statistical analysis suggested brain glucose partly accounted for the association between age and smaller gray matter volume. Blood glucose was higher in middle-aged than younger adults, while brain glucose was higher in older than middle-aged adults.
Why it matters
Problems using glucose for energy are implicated in age-related brain degeneration. The authors suggest brain glucose may help flag metabolic problems and nerve-cell vulnerability early.
Caveats
The cross-sectional design cannot show cause and effect or establish changes within individuals over time. The findings do not cover people with diabetes or neurological or psychiatric disorders, who were excluded.
The paper
Higher fasting brain glucose is associated with lower gray matter volume in healthy adults
Harvard University
Journal of Cerebral Blood Flow and Metabolism, Jul 19, 2026
