A new Mayo Clinic study finds that a milder type of mental decline that often precedes Alzheimer's disease is much more common than previously thought.
The study involved about 16-hundred people, ages 70 through 89, living in Olmsted County. All tested normal when they were enrolled in the study, but more than 5 percent had developed mild impairment when evaluated a year later. Men were nearly twice as likely as women to develop it.
MPR's Cathy Wurzer talked with Dr. Ron Petersen, the Mayo Clinic researcher who led the study.