Laughter is the best medicine, it is said, and smiling is good for the soul, but are there real physical health benefits to the act of smiling?
A new study suggests that smiling can improve stress response and related heart health. Interestingly, this remained true whether study participants were aware that they were smiling or not.
Also, the more muscles used in a smile, the greater benefit to stress response and heart health.
The study was conducted at the University of Kansas by Tara Kraft, graduate student, and Sarah Pressman, PhD, assistant professor of psychology.
"Age old adages, such as 'grin and bear it' have suggested smiling to be not only an important nonverbal indicator of happiness but also wishfully promotes smiling as a panacea for life's stressful events," says Kraft.
"We wanted to examine whether these adages had scientific merit; whether smiling could have real health-relevant benefits."
The researchers asked 169 participants to undergo training to hold a particular facial expression. The participants held chopsticks with their teeth in order to create the expression. Some held a neutral expression, while others held a smile. Only half of smiling participants were told that they were smiling, the others were not aware of the purpose of the chopsticks.
Some participants were instructed to smile with only muscles around their mouth while others were instructed to smile using muscles near their mouth and eyes. These smiles using more muscles are known as genuine, or Duchenne smiles.
After training, participants underwent a series of activities that were designed to be stressful. In one activity they had to trace a star with their non-dominant hand through the reflection in a mirror. In another activity they dipped their hand in ice water.
Heart rate was measured throughout the activities as well as self-reported stress levels. A researcher was present to ask specific stress-related questions throughout the activities.
Those who were smiling had lower heart rates and stress levels during the activities, even if they were not aware that they were smiling. Additionally, smilers showed shorter times before their heart rate returned to normal. Those holding Duchenne smiles showed the greatest benefit.
"The next time you are stuck in traffic or are experiencing some other type of stress," says Pressman, "you might try to hold your face in a smile for a moment. Not only will it help you 'grin and bear it' psychologically, but it might actually help your heart health as well!"
The study will be published in an upcoming edition of the journal Psychological Science and was funded by the University of Kansas. The study authors report no conflicts of interest.