Being older does not mean losing cognitive acuity.

MADRID (EFE).— The super-elderly, people over 80 years old with the brain of a 50-year-old, have been under scientific study for a quarter of a century in search of the formula for the best eternal youth, the one offered by having a healthy brain.

Since 2000, a team from Northwestern University (Chicago) has been trying to decipher the keys to the indestructible brains of the super-elderly by monitoring 290 people and performing autopsies on 77 donated brains.

Their findings were published yesterday in the journal “Alzheimer's & Dementia.”

The term super-elderly was coined by Marsel Mesulam, founder of the Center for Cognitive Neurology and Alzheimer's Disease at Northwestern University in the late 1990s.

Their goal was to use the study of these individuals' neurobiological profile to help find early therapies to maintain brain health in old age.

For researchers, a super-elder is a “person with exceptional social and memory performance, comparable to that of people at least three decades younger, challenging the belief that cognitive decline is an inevitable part of aging,” summarizes Sandra Weintraub, a researcher in the field of psychiatry at Northwestern.

Twenty-five years of testing have revealed that the memory performance of the super-elderly is exceptional, and their results on word and object recall tests are similar to those of 50- to 60-year-olds.

It's clear they're incredibly social people. They had different lifestyles and exercise habits, but they all had one thing in common: they had strong interpersonal relationships.

Autopsies reveal brain structures and characteristic cellular features. Dr. Weintraub emphasizes that their brain structure is youthful, since, "unlike brains that age normally, super-elderly individuals do not show significant thinning of the cortex, the outer layer of the brain."

This crucial brain region plays an important role in integrating information related to decision-making, emotions, and motivation.

Compared with the brains of other people their age, the super-elderly have higher than normal numbers of von Economo neurons, which are involved in social cognition, empathy, and decision-making, and larger entorhinal neurons, which are critical for memory.

Some of the 77 brains contained amyloid and tau proteins (also known as plaques and tangles), which play a key role in the progression of Alzheimer's disease, but others did not develop either.

"This indicates that they have brains that are extremely resistant to cognitive decline, because either they don't produce plaques or amyloid and tau tangles, or if they do, they don't affect their brains," Weintraub says.

Researchers welcome and encourage brain donations to science for postmortem study.