Like death and taxes, bodily aging is one of life's certainties-but cognitive aging might not be. The mental deterioration most people associate with aging is linked to the widespread thinning of the brain's outermost layer, the cortex.
The cortex is where consciousness lies, where all the neurons that fire thoughts and movements are housed. It is a critical part of the brain for higher-level thinking, memory and problem solving, and as you age, and it shrinks, function decreases.
However, a group of scientists have discovered that some seniors are "super agers," meaning they retain high cognitive functioning, memory and a thicker cortex as they age. For the study, led by Emily Rogalski, director of neuroimaging at Northwestern University's Cognitive Neurology and Alzheimer's Disease Center, the research team measured brain aging by examining the thickness of each person's cortex—the outer layer of folded gray matter in the brain. The team was attempting to understand what factors might set these super-aging seniors apart from their peers.
For the study, researchers tracked changes in cortex thickness for a year and a half in 24 super-agers and 12 average elderly people. Both groups lost brain volume due to aging, but MRI scans revealed that the super-agers were experiencing brain aging at half the rate of their regular-aging peers, 1.1% versus more than 2.2%.
"This suggests the super-agers are on a different trajectory of aging," Rogalski said. "They're losing their brain volume at a much slower rate than average."
This study adds to a growing body of research aimed at providing scientists with anti-aging "targets" that could be manipulated with medication or other therapies.