Effect of yoga on mental health: Comparative study between young and senior subjects in Japan

BACKGROUND: Japan has a large number of senior citizens. Yoga can be wisely applied in old age care. There is no any age restriction to practice yoga. The effect may differ by age. There is a need to study the mechanism of action of yoga with respect to age. AIM: This study was conducted in Japan to find the effect of yoga on mental health between young and senior people. MATERIALS AND METHODS: Twenty-five normal healthy volunteers of both sexes were divided into two groups according to age. Fifteen participants of the age group between 65 to 75 years and 10 participants of the age group between 20 to 30 years were selected. This study was approved by the ethical committee of Kawasaki University of Medical Welfare. Selected individuals were subjected to 90 min of yoga classes once or twice a week for a month. Salivary amylase activity was assessed before and after yoga practice. State Trait Anxiety Inventory (STAI) was given before yoga on the first day and after one month of practice to assess the change in State anxiety and Trait anxiety. RESULTS: Senior group – Salivary amylase activity decreased from 111.2±42.7 to 83.48±39.5 kU/L [average±standard deviation]. Younger group – Salivary amylase activity reduced from 60.74±31.8 to 42.39±24 kU/L. Senior group – State anxiety score decreased from 41.13 ±8.43 to 30.8±6.49, Trait anxiety score reduced from 45.66±7.5 to 40.73±8.3. Younger group – State anxiety score reduced from 38.7±4.8 to 30.8±4.1,Trait anxiety score reduced from 46.2±7.9 to 42.9±9.1. Changes were statistically significant with P<0.05. CONCLUSION: Decrease in Salivary amylase activity may be due to reduction in sympathetic response. Reduction in State and Trait anxiety score signifies that yoga has both immediate as well as long-term effect on anxiety reduction. Thus yoga helps to improve the mental health in both the groups.