People around the world are living longer than ever, and that shift is changing what many want from aging. The goal is no longer just more years, but more good years. That has put new attention on “healthspan,” the stretch of life when someone…

People around the world are living longer than ever, and that shift is changing what many want from aging. The goal is no longer just more years, but more good years. That has put new attention on “healthspan,” the stretch of life when someone…