Black Tea Aroma May Help Lower Stress Levels
A recent study suggests that inhaling the aroma of black tea may help lower stress levels after a stressful task. The same study also found that this may improve mood before experiencing mental stress.
Participants in the study included 18 healthy volunteers, five men and 13 women. The participants were between 20.4 and 21.2 years old and they were all instructed not to consume anything but water for three hours before each trial.
The participants used the Uchida-Kraepelin test in order to induce stress. This is a psycho-diagnostic test that involves arithmetic tasks that need to be solved within 30 minutes. The test was split over two 15-minute sessions. Between sessions participants were instructed to inhale either black tea aroma (Assam tea and Darjeeling tea) or they were exposed to warm water as a control.
The researchers measured salivary chromogranin-A (CgA) in order to measure stress levels. CgA is an acidic protein that is secreted in response to stress They found that inhaling the black tea aroma was associated with lower salivary CgA concentration levels after the full half hour of mentally stressful tasks, compared to placebo.
The anti-stress effect of the tea did not differ between the two teas. However, the Darjeeling tea tended to decrease the tension and anxiety score immediately after the first exposure.
Researchers from the University of Shizuoka in Japan conducted the study. It was published on January 24, 2018, in the Journal of Physiological Anthropology.