Some 80-Year-Old People Still Have Very Sharp Brains, and Now Scientists Know Why

Older adults classified as “SuperAgers” generate at least twice as many neurons in the hippocampus as their elderly peers, a new study has revealed.

These findings, published Wednesday by the University of Illinois at Chicago and Northwestern University, could help explain why SuperAgers have exceptional memory and cognitive resilience even well into their 80s.

Northwestern has been studying SuperAgers for decades, defining them as “extraordinary individuals aged 80 or older whose memory performance rivals that of people three decades younger.” Researchers use special memory retrieval tests to make this determination.

In this study, they analyzed postmortem brain tissue (almost 356,000 individual cell nuclei) focusing on the hippocampus, which is essential for forming new memories and supporting learning and spatial navigation.

They compared tissue from SuperAgers, typical older adults, older adults with early dementia/Alzheimer’s, and younger, healthy adults.

The researchers found that SuperAgers produced at least twice as many new neurons compared to “cognitively normal” older adults and those with Alzheimer’s pathology.

They also found that changes in certain brain support cells (astrocytes) and key memory cells (CA1 neurons) are linked to the preservation of cognitive ability, which helps keep the brain alert as we age.

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SuperAgers also had different patterns of gene activity in their brains compared to those with Alzheimer’s disease.

“SuperAgers have more neurons and immature neuroblasts in the hippocampus, which is an indication of stronger neurogenesis compared to other groups,” study co-author Changiz Geula, a research professor of cell and developmental biology and neuroscience at Northwestern University Feinberg School of Medicine, told News Digital.

“The study also showed that specific cells in the hippocampus display unique gene expression profiles that relate to neuronal function and transmission and are associated with higher cognitive function.”

The findings were published in the journal Nature.

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“We have always said that SuperAgers show that the aging brain can be biologically active, adaptive, and flexible, but we didn’t know why,” co-author Tamar Gefen, an associate professor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine and a neuropsychologist at Northwestern University’s Mesulam Institute for Cognitive Neurology and Alzheimer’s Disease, said in the statement.

“This is biological evidence that their brains are more plastic and a real discovery showing that neurogenesis of young neurons in the hippocampus may be a contributing factor.”

News Senior Medical Analyst Dr. Marc Siegel said the study uncovered signs of plasticity and regeneration in SuperAgers.

“It confirmed not only the preservation of brain tissue in the hippocampus, which is crucial for memory and cognition, but also the regeneration and further development of brain cells in that area,” Siegel, who was not involved in the study, told News Digital.

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“This is an important study because it may lead to certain cellular genetic treatments that could lead to more SuperAgers,” the doctor said. “It may also lead to more advanced testing to determine who will be a SuperAger and guide treatment and clinical management.”

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The study had some limitations, mainly that the research relied on tissue samples taken at a specific point, rather than tracking changes over time.

Geula noted that studies using human brain tissue typically involve fewer cases than animal research, which can be a limitation. However, he highlighted that each case in this study was carefully analyzed.

“While these findings cannot be directly translated to changes in daily life and activities, they suggest that cognitive resilience is associated with greater integrity of many brain systems,” he told News Digital. “This implies that addressing brain health is crucial to maintaining cognitive function in old age.”

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“Therefore, maintaining good overall health by keeping systemic diseases under control, maintaining a healthy diet and exercising, and ensuring that the elderly remain mentally active becomes more important.”

The study was funded by the National Institute on Aging, which is part of the National Institutes of Health.