I've known too many people who quit work -- especially those who "retired early" -- and then died within a year not to think there's something to this:
In a prospective cohort study of thousands of employees who worked at Shell Oil, the investigators found that embarking on the Golden Years at age 55 doubled the risk for death before reaching age 65, compared with those who toiled beyond age 60.
The person I think of especially is Barbara, someone I worked with in Michigan City. She was a reporter for the newspaper when World War II started, then found herself in management because all the men were gone. The war ended and she was put back into worker-bee status, just like her "Rosy the riviter" counterparts in industry. She stayed with the paper because it was her life. She finally retired, telling us all about all the things she was going to do that she'd never gotten around to. She was dead within a few months.
When you remove people's purpose for living, you can remove their drive to keep on living. For many people, perhaps most, their jobs provide that purpose.