Sedative effects of roasted green tea aroma on autonomic nervous activity, central nervous activity, and subjective mood state in healthy adults

Authors

  • Akio Sugimoto
  • Yuka Tatsumi
  • Masaki Ichitani

DOI:

https://doi.org/10.31989/ffhd.v15i1.1467

Abstract

Introduction: To clarify the physiological and psychological effects of roasted green tea aroma, this study examined the effects of roasted green tea extract and its major aromatic components on autonomic nervous activity, central nervous activity, and subjective mood state.

Methods: Twenty healthy adults who were not averse to the aroma of green tea, did not smoke, did not display any flu symptoms, and were not receiving drug treatment participated in this study. The study samples comprised a roasted green tea extract from Shizuoka first-growth green tea (Test I) and three pyrazines, which are the main aromatic components of roasted green tea (Test III). The pupil miosis rate, peripheral skin temperature, and cerebral blood flow were measured after 2 min of inhalation of the study samples as physiological evaluations. Subjective mood state was investigated using a questionnaire for psychological evaluation.

Results: The results showed that inhalation of roasted green tea aroma significantly increased the pupillary miosis rate and peripheral skin temperature, similar to the effects observed with hot water. Furthermore, inhalation of roasted green tea aroma reduced the amount of oxygenated hemoglobin in the prefrontal cortex, suggesting that it also has a sedative effect on the central nervous system. In the psychological evaluation using the Visual Analog Scale, roasted green tea aroma inhalation reduced the scores for “tension”, and “anxiety” while increasing those for “mood” and “comfort” relative to those observed with hot water. In addition, the evaluation of the main aromatic components of roasted green tea, specifically three different pyrazines, demonstrated physiological effects similar to those of roasted green tea even at room temperature when tested at concentrations derived from the results of the analysis.

Conclusion: The aroma of roasted green tea has both physiological and psychological sedative effects that differ from those of hot water and suggest that these pyrazines play a role in producing these effects, with 2,3,5-trimethylpyrazine being the most important aromatic component. Furthermore, the findings suggest that roasted green tea aroma exerts a sedative effect on the autonomic nervous system by suppressing sympathetic nerve activity while increasing parasympathetic nerve activity.

Published

2025-01-15

Issue

Section

Research Articles