Chinese scientists today reported that after five days of training in meditation, students had lower levels of the stress hormone cortisol in their saliva after a stress test, compared with students who got five days of instruction in a relaxation technique that didn't involve meditation.
The study included 80 undergraduate students at Dalian University of Technology in Dalian, China.
Over five days, half of the students learned to meditate for 20 minutes per day.
While meditating, they focused on their breathing and mind-body harmony without trying to control their thoughts.
For comparison, the other 40 students spent an equal amount of time learning progressive relaxation, in which they relaxed muscles in different parts of their body.
Both groups of students had an instructional CD and a coach to help them learn meditation or progressive relaxation.
Stress Test
Before and after their training, the students took a mood survey.
Those in the meditation group reported boosting their energy and reducing their anger, depression, anxiety, and fatigue after their training. No such benefits were seen in the progressive relaxation group.
After their training ended, the students also took a stress test in which they were required to do mental arithmetic quickly.
The students had to subtract the number 47 in their heads from a string of four-digit numbers and say the answers as quickly as possible. When they were wrong, they heard a harsh sound from a computer and had to start over.
Immediately before and after the math quiz, the students provided saliva samples. Then they got one more 20-minute session of meditation or progressive relaxation, after which they provided a third saliva sample.
The researchers -- who included Yi-Yuan Tang, PhD, of Dalian University of Technology -- measured levels of the stress hormone in the students' saliva.
Meditation and Stress Reduction
Cortisol levels rose for all of the students immediately after the math test. That shows that the test was stressful for everyone, Tang's team notes.
But after meditating or practicing progressive relaxation for 20 minutes, the meditating students had a bigger drop in their cortisol levels compared with those who practiced progressive relaxation.
Because the meditation training CD also included music and mental imagery, Tang and colleagues point out that it's not clear if the results were solely due to meditation.
But in general, the researchers say the meditation program helped the students handle stress, even though they had been meditating for less than a week.
The findings appear in this week's advance online edition of Proceedings of the National Academy of Sciences.