We have previously reported black tea aroma exhibits a sedative effect by suppressing sympathetic nerve activity and elevating parasympathetic nerve activity. Enhancement of sleep quality is also expected from the sedative effect of this aroma. The effect of black tea aroma on sleep in 20 women with high stress consciousness and sleep disorders; was evaluated in this study using data collected from questionnaires and physical activity measured over a 14 day test period. Psychological effects of reduced stress consciousness were improvement in sleep quality, and greater satisfaction with ease in falling and staying asleep; while physiological data showed reduced sleep latency, an increase in total sleep time, and a significant increase in sleep efficiency. These results strongly suggest black tea aroma improves overall sleep.
