The stress-reducing effect of kabusecha on highly stressed persons

Abstract

　This study investigated the stress-reducing effect of kabusecha containing of high amounts of theanine, a nutritional component of green tea, on daily high-stress person.

　The subjects were 109 college students and staffs who live in different environments (12 men, 97 women, 19-67 years). Twenty-nine person with high stress (2 men, 27 women, 19-58 years old) were selected by Stress Response Scale-18 (SRS-18), one of the subjective stress evaluation methods. As a single-blind study, a 30-days tea challenge was conducted on them divided into two groups, one is kabusecha containing theanine and the other is barley tea without theanine. The quantitative stress level was assessed with SRS-18 and salivary amylase and blood pressure as objective stress evaluation methods. The quantitative stress levels were assessed with salivary amylase and blood pressure as objective stress evaluation and SRS-18 as subjective evaluation.

　As a result, the salivary amylase level and SRS-18 score decreased significantly in the kabusecha group. It was speculated that kabusecha has an anti-stress effect by suppressing the autonomic nervous system pathway, especially the sympathetic nervous-adrenal medullary axis. Interestingly, blood pressure and SRS-18 score also decreased significantly in the barley tea group. It was considered that barley tea induces a stress-reducing effect by a stress response activation pathway different ,from that of kabusecha.

　These findings suggested that kabusecha has the stress-reducing effect of on someone with high stress in daily life using a combination of subjective and objective measures of stress. In the future, it is expected that as one of the stress coping methods, people could select the tea according to individual stress by clarifying the involvement of various nutritional components in the psychological stress-reducing effect.