Humor breaks through feelings of isolation and alienation. Laughing is a psychological coping mechanism, but it also has physiological effects. It increases heart rate, stimulates circulation and exercises the muscles, Jones said. This increases oxygen to the brain and a sense of relaxation follows. Many studies have shown that a positive attitude can bolster the immune system.
More recent studies show that laughter also can help prevent heart problems.
Cardiologists at the University of Maryland Medical Center in Baltimore recently discovered that people with healthy hearts are more likely than people with heart disease to have a sense of humor. We don't know why laughing protects the heart, but we know that mental stress can cause a series of inflammatory reactions leading to fat and cholesterol buildup in the coronary arteries, and ultimately to a heart attack. In the study, researchers compared the humor responses of 300 people. Half of the participants had either suffered a heart attack or had undergone coronary artery bypass surgery. The other 150 were healthy, age-matched participants who did not have heart disease.