So-called “SuperAgers” lose brain volume more slowly than their normally aging peers, protecting them from dementia, according to a new study that proves yet again that Alzheimer’s disease — like other dementias — is not an inevitable fate in predestined individuals.
The study, “Rates of Cortical Atrophy in Adults 80 Years and Older With Superior vs. Average Episodic Memory,” appeared in JAMA. Senior author Emily Rogalski of Chicago’s at Northwestern University will present her team’s findings April 6 at the 2017 Cognitive Aging Summit in Bethesda, Md.
Earlier research on SuperAgers — people older than 80 with an episodic memory at least as good as that of the average middle-aged adult — has shown that they have a thicker brain cortex than other people their age. But nobody knew whether this was thanks to a larger brain from the beginning, or lower rates of decline.
Researchers recruited both SuperAgers and normally aging people to its study, which followed participants over time. Among the 24 SuperAgers, 75 percent were women, and 96 percent were white. Women made up 42 percent of the 12 normally aging participants. Except for better scores in episodic memory and category fluency tests — naming as many animals as one could think of — there were no differences between the two groups.
But when researchers measured annual brain volume loss, it became evident that SuperAgers lost less brain volume than normally aging adults.
“Increasing age is often accompanied by ‘typical’ cognitive decline or, in some cases, more severe cognitive decline, called dementia,” clinical neuropsychology doctoral student Amanda Cook said in a Northwestern update covering the research. “SuperAgers suggest that age-related cognitive decline is not inevitable.”
The article in Northwestern Now featured one of the participants — Donald Tenbrunsel, 89, who has made a habit of keeping up to date with the world of his grandchildren, as he lives with his daughter’s family.
“I have to adapt to that kind of life,” Tenbrunsel told Northwestern’s Kristin Samuelson. “They don’t know much about Frank Sinatra or Franklin Delano Roosevelt, so I have to keep saying, ‘Is the Chance the Rapper coming this week or is it Taylor Swift?’”
While SuperAgers lost, on average, 1.06 percent per year in total brain volume, normally aging adults lost 2.24 percent.
“For this study we explored whether SuperAgers’ brains were on a different trajectory of decline,” said Rogalski, associate professor at Northwestern’s Cognitive Neurology and Alzheimer’s Disease Center. “We found that SuperAgers are resistant to the normal rate of decline that we see in average elderly, and they’re managing to strike a balance between lifespan and health-span, really living well and enjoying their later years of life.”
Instead of examining the brains of people who develop dementia, the research team thinks it may be possible to identify biological factors or processes that protect people from dementia.
“Sometimes it’s useful to turn a complex problem on its head and look from a different vantage point,” Rogalski said. “The SuperAging program studies people at the opposite end of the spectrum: those with unexpectedly high memory performance for their age.”