This has been known for many years; recent clinical research has proven it over and over. I've been saying it for years, but recently faced the truth that I don't laugh enough, likely one of the prime reasons I had open heart surgery five years ago.
In contrast a friend of many years, now almost 90, laughs at virtually every opportunity. His life has been full of adversity, and one would expect him to have departed this life years ago, but he goes on-- laughing, enjoying every minute as it comes. Much like Bob Hope did.
In the hospital I use a set speech. Giving the patient our brochure on the chaplaincy program, I tell them we have a chaplain on call 24 hours a day. Then, "If you find yourself staring at the ceiling at 3 in the morning, get the chaplain up here... (most of them nod in agreement here).. let him pray for you (still agreement) maybe he will put you to sleep." Many (maybe most of them) find that very funny, and we enjoy a good laugh. Healing! yes, yes, it is!
A very prominent man named Norman Cousins had written many important books, then came down with an incurable cancer. His doctor suggested that he try laughing. He did, and as a consequence wrote a really important book, Anatomy of an Illness, explaining how laughter had cured his cancer. It happens!
Would you believe that when I looked up this phrase in google, it came forth with literally dozens of sites more or less of the same name. Here's one.
Laugh and the whole world laughs with you. You can be darn sure the good Lord has a terrific sense of humor.