Does laughter help you live longer?

We use more muscles to frown than we do to smile.Laughter is the best medicine.Now,obviously these are fairly general statements but do you believe that being a person with a lot of laughter in their lives, someone who has a well developed sense of humour, who is able to see the funny side of life’s ups & downs,is at least in theory going to live to a ripe old age.Of course laughing uncontrollably while crossing a road for example could result in one’s life ending premarturely.