There have been studies on whether being happy makes you healthier, and yes there is a correlation between it: http://www.hsph.harvard.edu/news/magazine/happin

There have been studies on whether being happy makes you healthier, and yes there is a correlation between it: http://www.hsph.harvard.edu/news/magazine/happiness-stress-heart-disease/ http://www.hsph.harvard.edu/news/magazine/happiness-stress-h... Whether that's due to this, or just the fact that the brain controls the release of stress hormones into the bloodstream is a different question.