At 80, he is a leading expert on dementia. Here’s how he keeps his brain healthy.

For over 50 years, Ron Petersen has studied healthy aging, cognition and dementia.

Petersen’s research established the concept of mild cognitive impairment, which falls between healthy cognitive aging and dementia. This idea has changed the way doctors and scientists study cognitive health with a focus on earlier detection and lifestyle changes. Petersen has co-authored more than 1,500 peer-reviewed articles and works full-time in clinical research as director of the Mayo Clinic Study of Aging, where he also sees patients.