I previously noted the main point of Howard Friedman and Leslie Martin's The Longevity Project.
The fruit of an eight-decade longitudinal study of talented kids, begun in 1921 by Lewis Terman, the book comes to this conclusion:
"Conscientiousness … turned out to be the best personality predictor of long life … The young adults who were thrifty, persistent, detail oriented, and responsible lived the longest."
Friedman and Martin offer three reasonable guesses about why this is so.
First, the conscientious are usually prudent, taking only sensible risks.
Second, they may be healthier in general - not just healthy living, but healthy basic constitutions.
Third, they create healthy relationships with other people, which not only makes us healthier, but also happier.
Go persistent prudence!