‘Superagers' seem to share this one key personality trait

National Geographic

3 days ago

The brains of superagers are different from the rest of us. Here's what 25 years of research reveals about why some people remain sharp well into their 80s and 90s. There's no one lifestyle linked to staying impressively sharp as you age—but a new study suggests there is at least one personality trait: gregariousness. Brain scans and post-mortem examinations of superagers reveal several differences that may explain their outgoing behavior. Photograph by Britt Erlanson, Getty Images
What if you could stay sharp in old age? We may be closer to understanding how some people over 80 became what's known as 'superagers'—meaning they have the cognitive function of someone decades younger.
In a new paper published in the journal Alzheimer's & Dementia, researchers at Northwestern University reveal what they've learned in the last 25 years of studying more than a hundred superagers—and analyzing some 77 post-mortem superager brains. The new paper shows that the brains of superagers share a host of characteristics that may allow them to retain their cognitive function.
And while there's still much to understand about whether lifestyle choices play a role, researchers did observe one personality trait that all superagers seem to share: they're sociable.
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The findings further contributed to developing a 'distinct neurobiological signature' for identifying superagers: You might be one if you're 80 or older and can recall at least nine words about 30 minutes after someone reads you a 15-word list.
Eventually, this research could build the foundation for future neurodegenerative disease interventions.
'​​One creative and novel way to understand or prevent Alzheimer's disease is to study those that don't get it,' says Tamar Gefen, a study author and assistant professor of psychiatry and behavioral sciences at Northwestern University.
That's why superagers are so fascinating, she says. 'Their memories are just outstanding even compared to their peers.' Superagers are outgoing—and tenacious
You might not be able to control the characteristics of your brain. But the Northwestern researchers have studied whether there are any lifestyle or personality traits that superagers share, and just one trait stood out—gregariousness. 'These are people living life on their own terms,' Gefen says.
Whether that means volunteering in communities, or having 'multiple romantic partners,' as some study participants did, it's clear superagers are connected by their values of autonomy and connection, adds Gefen.
Her team found potential biological underpinnings for these differences. The study shows superagers have more of a certain type of neurons associated with sociability compared to their peers—and surprisingly, more of these neurons than people much younger. Known as von Economo neurons, they are found in the anterior cingulate gyrus of the brain, which plays a role in emotion and cognitive processing.
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'You really only find these in species that are social, like whales,' says Joel Kramer, a professor of neuropsychology at the University of California, San Francisco. His team is currently studying frontotemporal dementia patients, and so far found a 'striking loss' of von Economo neurons in those who are less empathetic.
Indeed, the study notes these neurons have been found in emotional and social animals like great apes, elephants, and cetaceans like whales or dolphins. Animals 'that have strong connections tend to outlive and outsmart their peers. It's like the pack culture,' Gefen says.
Having a thicker anterior cingulate gyrus also suggests superagers are more tenacious. This is a region that is 'traditionally not associated with memory, but motivation,' says Alexandra Touroutoglou, an assistant professor of neurology who also studies superagers at Harvard University. 'This may reflect that superagers may be more willing to exert effort in the face of challenges.'
Northwestern researchers Sandra Weintraub and Marsel Mesulam founded the SuperAging Research Program more than 25 years ago after they examined a post-mortem brain of an 81-year-old woman with the cognitive function of someone in her 50s that they had received from the University of Miami's Miami Brain Endowment Bank. This finding challenged the prevalent idea that severe cognitive decline is unavoidable with age.
Fast forward decades later, and Northwestern has built up a brain bank of its own with 77 post-mortem brains, says Gefen, which she finds particularly exciting, as autopsy is considered the gold standard for identifying the causes and progression of disease.
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One key finding from the study is that cortical thinning, or brain shrinkage, in superagers is much slower than their peers—which may explain why they're less prone to neurodegeneration associated with conditions from dementia to Parkinson's disease. Over an 18-month period, superager cortical thickness was reduced by 1.06 percent, while peers' reduced by 2.24 percent. The researchers speculate in the paper that superagers could have been born with bigger brains; however, that 'is unlikely to be the entire answer given the absence of obvious differences in skull morphology.'
Additionally, superagers had a more robust cholinergic system, a neurotransmitter system associated with memory, learning, and motor function. Cholinergic neurons in the basal forebrain are thought to be among the first to show degeneration as you age. They communicate with each other via the neurotransmitter acetylcholine, which is important for alertness, explains Kramer.
For example, Kramer says the reason why you might feel 'a little dopey and not so sharp' when you take anti-seasickness medication is because it reduces acetylcholine. On the other hand, modern dementia therapeutics like donepezil slow the breakdown of acetylcholine by inhibiting an enzyme, acetylcholinesterase, thus making you less forgetful.
The Northwestern study found that among participants' acetylcholinesterase-rich neurons, superagers had less of the enzyme than their peers. This may suggest acetylcholine degrades slower among superagers, and possibly make them more resistant to worsening memory.
Superager brains may also be more resistant to the changes in the brain linked to Alzheimer's. An autopsy of a 92-year-old superager in the Northwestern study showed prominent neurofibrillary tangles, a hallmark of the disease. But the superager also had a 'much greater' amount of viable, healthy neurons, which could play a 'decisive role' in memory.
'This is an important finding, because it underscores that superagers may not avoid all pathological age-related brain changes,' Touroutoglou says. 'It also shows the viable neurons may play an important role that has not been studied.' Does lifestyle make a difference?
Surprisingly, the study found little difference between the cognitive performance of superagers who lived healthy lifestyles—i.e. ate well and exercised—and those who did the opposite.
Still, this should be interpreted with caution, experts say. Because this isn't a controlled longitudinal study that started when people were young, 'you cannot completely know whether these sorts of behaviors are helping or not,' Gefen says.
Further, other research suggests that lifestyle does indeed play a role. In 2024, for example, a commission from The Lancet estimated that up to 45 percent of dementia cases may be preventable if people adopt regular exercise or abstain from excess intoxication.
'I think it's absolutely true lifestyle matters. There's too much evidence,' Kramer says. 'The question is not, 'does everyone have to exercise?' The question is, 'if exercise and lifestyle don't explain everything, what are other things that explain this?''
Maybe it's genetics. But when it comes to superagers, currently 'we have more questions than answers,' Kramer says.
Fortunately, researchers are working on this. Gefen is especially excited about the new discoveries the Northwestern brain bank may bring; for example, her team is investigating what makes von Economo neurons special and their role in disease resistance. 'You can just imagine what the future holds in that SuperAging brain bank.'