A surprising number of people 100 and older show little or no signs of cognitive decline. Researchers call them “cognitive super-agers,” and they’re trying to figure out how and why they stay mentally sharp.
One of those researchers, whose work is reported here, is Emily Rogalski, Ph.D., at Northwestern University’s Feinberg School of Medicine. She’s spent a decade studying people aged 80 through the 100s.
She found that the super-agers’ brains “look indistinguishable from a group of healthy 50- to 60-year-olds. They really seem to be on a different trajectory.” To help understand why, she researched and evaluated their life stories, focusing particularly on how they dealt with stress, “whether it has involved surviving a Nazi death camp, coping with the death of a child, or dealing with cancer.”
There appeared to be a common theme: “It seems like these super-agers are particularly good at identifying the best in a situation and figuring out how to move on.”
But could there be other factors? Was there any physical differentiation in their brains?
Here the evidence is intriguing, and in different directions.
A 90-year-old brain typically weighs almost 10% less than a 40-year-old brain, with the shrinkage primarily affecting “the prefrontal cortex and hippocampus as well as the cerebral cortex, a part of the brain used for complex thoughts.
“But people who attain exceptional ages have been found to have a thicker cingulate cortex, a region believed to play an important role in attention, cognitive control, decision-making, and memory. Super-agers’ cerebrums also have been shown to include many more corkscrew-shaped von Economo neurons, which are involved in rapid communication across the brain, and their brains just generally seem to handle the wear and tear of aging better.”
OK, does that mean centenarians “are born with larger, stronger brains?” Or do they adapt somehow to aging?
Enter a new study of 340 healthy Dutch centenarians who were living independently.
The study found they “experienced no decline in major cognitive measures, except for a slight loss in memory function” akin to what one might expect if they were in their 70s. Some of the studied centenarians, in fact, had brains that appeared very healthy, and they performed at a high level on cognitive tests.”
Some had died “with no discernible degradation of their memories or their abilities to relate to others and solve problems.” But here’s where it gets contradictory again: when their brains were examined, “their gray matter was as marred and scarred as that seen in people who die with advanced Alzheimer’s.” Yet their brain function was never compromised — and the oldest was 108.
So they did suffer physical weakening or damage, yet no cognitive damage. Which would seem to mean: adaptation, not physical differentiation.
So which is it? The jury is still out, it appears.
The article quotes Henne Holstege, from the Dutch research team at Vrije University in Amsterdam: “Some individuals reach ages beyond 100 years and become centenarians with intact cognitive functions, which indicates that cognitive impairment is not inevitable at extreme ages. “It is still not clear to what extent individuals who maintain cognitive health at age 100 escape or delay decline.”
The good news: “Debilitating brain disease is nowhere near as inevitable as it once seemed, and many super-agers appear to be resistant, resilient, or both.”
(Photo credit: Trifonox_Evgeniy at iStock by Getty)