March 25, 2026
What makes the brains of so-called super agers—those aged 80 and older who remain as mentally sharp as someone 30 years younger—so robust? It may be their ability to generate new brain cells, even into very old age. A new study found that super agers generate more than twice as many new neurons as their less mentally nimble peers.
“This is a big step forward in understanding how the human brain processes cognition, forms memories and ages,” said study author Orly Lazarov, a professor at the University of Illinois at Chicago College of Medicine. “Determining why some brains age more healthily than others can help researchers make therapeutics for healthy aging, cognitive resilience and the prevention of Alzheimer’s disease and related dementia.”
Scientists have long recognized that humans generate new brain cells early in life, a process called neurogenesis. But it has only been in recent decades that scientists have begun to recognize that neurogenesis occurs in the adult brain as well. Much of this new brain cell growth in adults occurs in the hippocampus, a brain region critical for memory and learning one of the first areas damaged by Alzheimer’s disease.
For the new study, published in Nature, researchers analyzed donated, post-mortem hippocampal brain samples from 38 individuals representing five groups: healthy young adults; healthy older adults; older adults with exceptional memory, or super agers; individuals with mild or early dementia; and those diagnosed with Alzheimer’s disease. They looked for neurons at various stages of maturation, indicating active new brain cell growth.
The researchers found that super agers were actively producing far more new brain cells than their peers with memories more typical for their age. New brain cell growth was greatly diminished in those in the early stages of dementia, and minimal in those with Alzheimer’s disease.
“Super agers had twice the neurogenesis of the other healthy older adults,” Dr. Lazarov said. “Something in their brains enables them to maintain a superior memory. I believe hippocampal neurogenesis is the secret ingredient, and the data support that.”
Furthermore, the researchers found that the new neurons in the brains of super agers had a distinct “epigenetic signature,” an often reversible modification to the underlying DNA that influences gene expression. These epigenetic changes are typically affected by environmental or lifestyle factors. The researchers plan to study these changes further to better understand how lifestyle factors like diet and exercise and disorders like high levels of body-wide inflammation may work alongside neurogenesis to impact the aging brain.
“What’s exciting for the public is that this study shows the aging brain is not fixed or doomed to decline,” said Ahmed Disouky, the study’s first author. “Understanding how some people naturally maintain neurogenesis opens the door to strategies that could help more adults preserve memory and cognitive health as they age.”
The study was small, and more research is needed to better understand why some people make it to very old age free of serious memory problems or Alzheimer’s disease. But the findings offer encouragement to any of us concerned about the effects of aging on the brain.
Knowing that parts of the brain maintain a regenerative capacity throughout life and that new neuron growth likely continues well into our 80s and beyond suggest it’s never too late to take steps to support brain health. Regular exercise, mental stimulation, not smoking, keeping blood pressure in check and maintaining a heart-healthy diet are among the steps that have been shown to prevent or delay the onset of Alzheimer’s disease. And your brain will thank you, no matter your age.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Ahmed Disouky, Mark A. Sanborn, K. R. Sabitha, et al: “Human hippocampal neurogenesis in adulthood, ageing and Alzheimer’s disease.” Nature, February 25, 2026
