In a study of nursing home patients by researchers Ellen Langer and Judith Rodin, residents on one floor were given a plant for which they themselves were expected to care (the experimental group) while residents on another floor were given a plant for which their nurses would care (the control group). After three weeks, 93 percent of residents in the experimental group showed an overall improvement in socialization, alertness, and general function; in contrast, for 71 percent of residents in the control group functioning actually declined. And in a follow-up study eighteen months later, half as many of the residents who’d received plants for which they were expected to care by themselves had died as the residents who’d been given plants for which their nurses cared.

via How do I live longer? Here are 10 ways backed by evidence.

Great post.  To sum up: exercise, be happy, be optimistic, tell yourself aging is a good thing, and get a plant.