Smiling releases "feel good" chemicals in the body.
The scientific evidence has been steadily accumulating: negative emotions like anger, fear, and sadness as well as the repeated activation of the stress response can have a negative effect on the immune system and may also put you at higher risk for a range of diseases.
On the other hand, research tell us that optimism typically has a positive affect on the immune system and one’s health. According to researcher Suzanne Sergerstrom,
“…a number of studies show that optimists are in general both psychologically and physiologically healthier.”
Traditional Chinese Medicine also suggests that laughter, pleasure, optimism, and boosting your spirits in other enjoyable ways can have a positive knock-on effect for your immune system and general well being. The “radiant circuits” – the meridian systems interconnected with the immune system – are thought to be highly responsive to your thoughts, images, and beliefs. Shifting your mind set can sometimes have an instantaneous effect.