Changiz Geula, Ph.D. and colleagues have discovered elderly people with super-sharp memory — “super-aged” individuals — who somehow escaped formation of brain “tangles,” which consist of an abnormal form of a protein called “tau” that damages and eventually kills nerve cells.

Environment, lifestyle, and genetics may be key factors. Some super-aged individuals might have a genetic predisposition to being super-aged, while others may help preserve high brain function by maintaining a healthy diet or staying physically active. Others may keep mental decline at bay by keeping the brain itself active.