Study Uncovers Why Some Brains Stay Sharp in 80s

Age-related memory decline is common in people in their 80s and 90s, often marked by forgetfulness, slower thinking, and difficulties with language, focus, or judgment. These changes are typically linked to gradual brain cell loss and reduced neural connectivity. However, a rare group of older adults known as “super-agers” appears to defy this trend, maintaining memory abilities comparable to individuals decades younger.

A new study from the University of Illinois College of Medicine, published in Nature, investigated the biological mechanisms that may explain this remarkable cognitive resilience. Researchers analyzed 38 post-mortem brain samples from older adults with varying levels of cognitive function, including super-agers and individuals with typical age-related decline.

The team focused on neurogenesis—the process of forming new neurons—which continues in certain parts of the brain even in adulthood. Particular attention was given to the hippocampus, a critical brain region involved in memory formation and spatial navigation.

Scientists examined genetic markers associated with neural stem cells, neuroblasts (developing nerve cells), and immature neurons. These represent different stages in the development of new brain cells, from early “stem-like” cells to nearly mature neurons capable of integrating into neural circuits.

Although evidence of neurogenesis was found across all groups, super-agers had significantly higher numbers of immature neurons in their hippocampi. This suggests that their brains retain a stronger ability to generate and preserve new neurons well into advanced age.

The findings indicate that super-agers display enhanced neuroplasticity—the brain’s capacity to adapt, reorganize, and form new connections. While researchers have not yet established a direct cause-and-effect relationship, the study reinforces the idea that sustained brain cell renewal may help protect memory and cognitive function later in life.

REFERENCE: Disouky, A., Sanborn, M.A., Sabitha, K.R. et al. Human hippocampal neurogenesis in adulthood, ageing and Alzheimer’s disease. Nature (2026). https://doi.org/10.1038/s41586-026-10169-4