Can laughing more delay aging? What is the allusion of the sentence "Smile, ten years younger"?

Smile often in life, that is, adjust your mentality and learn to face setbacks in life with an optimistic and positive attitude. From a medical point of view, laughing often is also helpful to your health, fully mobilize your muscles and relax your nerves. As the saying goes, "Laughter is ten years old", and modern medicine also believes that laughter has ten close relationships with people's health and longevity. The advantages of laughter are: 1. Increase the respiratory function of the lungs; 2. Clean the respiratory tract; 3. Express healthy feelings; 4. Eliminate nervous tension; 5. relax muscles; 6. It helps to disperse excess energy; 7. Dispel gloom; 8. Remove the sense of "social bondage"; 9. Help to overcome shyness; 10. Laughter can help people adapt to the environment and treat life optimistically.