Abstract
It is becoming clear that concentration improves the immune capabiliy. Zazen is considered as one concentration method. The changes occurring in the levels of natural killer (NK) cell activity, CD4, CD8 and the ratio of CD4/CD8 in venous blood before and after 40-minute zazen were simultaneously measured. A total of thirteen monks ranging in age from 21 to 78 with 2 to 50 years of experience in zazen. The level of NK cell activity was 22.7±7.1% during the rest period, and decreased to 19.6±5.5% after Yaza were practiced for 40 minutes in the night. In Soushinza, which was conducted in the morning, the rest value of NK cell activity level was 41.1±17.9%, and decreased to 36.9±18.3% (p<0.05). No significant difference was seen between Yaza and Soushinza in the level of NK cell activity. The level of CD4 showed an increase, but the CD8 level showed a tendency to decrease slightly and, consequently, the ratio of CD4/CD8 increased after Yaza and Soushinza. It is presumed that the immune capability was stimulated and caused improvement.
