A new 25-year Northwestern University study is challenging the idea that memory loss is an unavoidable part of aging.
Researchers say a small group of seniors, known as “super agers,” are proving that mental sharpness can last decades longer than most expect.
Super agers are people 80 and older whose memory matches that of someone 30 years younger.
According to Dr. Sandra Weintraub, a professor of psychiatry and neurology at Northwestern’s Feinberg School of Medicine, the term is based on exceptional performance in memory tests, not a medical condition. “Loss is not inevitable,” Weintraub said. “If your relative is forgetful at age 80, it may not be part of aging, but of disease.”
Northwestern’s SuperAging Research Program has spent decades studying more than 100 of these individuals, including 77 post-mortem brains.
Their findings, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, reveal that super agers’ brains have unique traits that may protect against age-related decline.
Some of these seniors’ brains contained few of the amyloid plaques and tau tangles linked to Alzheimer’s disease, suggesting a biological “resistance” to degeneration. Others had high levels of these proteins but still retained their cognitive abilities—an example of “resilience.”
Unlike typically aging brains, super agers’ cortices—the outer brain layer tied to decision-making and emotional regulation—remain thicker over time. Over an 18-month period, their cortical thickness shrank by about 1 percent, compared to more than 2 percent in their peers.
Researchers also found higher numbers of von Economo neurons, brain cells tied to social behavior and empathy. These neurons, which are also found in highly social animals like whales and great apes, may play a role in resilience.
Super agers were also more likely to have larger entorhinal neurons, which are vital for memory.
The study notes that many of these individuals share a common personality trait—gregariousness. They tend to be highly social, value personal connections, and often lead active, engaged lives.
Another key difference is in the brain’s cholinergic system, which supports memory and learning. Super agers had lower levels of the enzyme acetylcholinesterase, meaning their brain’s acetylcholine—a chemical essential for alertness—may degrade more slowly. This could help explain why their memory remains strong.
While lifestyle differences weren’t dramatic in this study, researchers caution against dismissing healthy habits. “What’s good for your heart is good for your brain,” Weintraub said, urging seniors to eat well, exercise, sleep enough, and maintain strong relationships.
Outside experts, like Christopher Weber of the Alzheimer’s Association, say the findings could lead to better strategies for preventing or treating cognitive decline.
The study group was small and mostly made up of well-educated White participants, but scientists still view the findings as an important step.
As Weintraub and her colleagues continue building their SuperAging brain bank, they hope to unlock more secrets to healthy aging.