The 90+ study, Alzheimer's and aging

An elderly couple stroll on the sea front.
An elderly couple stroll on the sea front in the early morning in Hythe, England.
Photo by Peter Macdiarmid/Getty Images

Neurologists at the University of California are studying a group of men and women over the age of 90 for clues on how the brain is affected by aging.

What they are learning about these "nonagenerians" is providing new clues about longevity and aging well, and important data on Alzheimer's disease and dementia.