著者

堀川 知廣 中村 順行 森田 明雄 Tomohiro HORIKAWA Yoriyuki NAKAMURA Akio MORITA

雑誌

静岡産業大学情報学部研究紀要 = Bulletin of Shizuoka Sangyo University

巻号頁・発行日

vol.17, pp.343-373, 2015-03-01

著者

Keiko Unno Hiroshi Yamada Kazuaki Iguchi Hitoshi Ishida Yasunori Iwao Akio Morita Yoriyuki Nakamura

出版者

公益社団法人日本薬学会

雑誌

Biological and Pharmaceutical Bulletin (ISSN:09186158)

巻号頁・発行日

vol.40, no.6, pp.902-909, 2017-06-01 (Released:2017-06-01)

参考文献数

38

被引用文献数

19

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Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the effect of theanine was blocked by caffeine and gallate-type catechins, which are the main components in tea. We examined the anti-stress effect of green tea with lowered caffeine, low-caffeine green tea, on humans. The study design was a single-blind group comparison and participants (n=20) were randomly assigned to low-caffeine or placebo tea groups. These teas (≥500 mL/d), which were eluted with room temperature water, were taken from 1 week prior to pharmacy practice and continued for 10 d in the practice period. The participants ingested theanine (ca. 15 mg/d) in low-caffeine green tea. To assess the anxiety of participants, the state-trait anxiety inventory test was used before pharmacy practice. The subjective stress of students was significantly lower in the low-caffeine-group than in the placebo-group during pharmacy practice. The level of salivary α-amylase activity, a stress marker, increased significantly after daily pharmacy practice in the placebo-group but not in the low-caffeine-group. These results suggested that the ingestion of low-caffeine green tea suppressed the excessive stress response of students. This study was registered at the University Hospital Medical Information Network (ID No. UMIN14942).

著者

Keiko Unno Shigenori Noda Yohei Kawasaki Hiroshi Yamada Akio Morita Kazuaki Iguchi Yoriyuki Nakamura

出版者

SOCIETY FOR FREE RADICAL RESEARCH JAPAN

雑誌

Journal of Clinical Biochemistry and Nutrition (ISSN:09120009)

巻号頁・発行日

vol.61, no.3, pp.210-216, 2017 (Released:2017-11-01)

参考文献数

51

被引用文献数

26

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Epidemiological and animal studies have demonstrated that ingestion of green tea enhances healthy life. However, caffeine in green tea can interfere with sleep. In this report, we examined the effect of green tea with lowered caffeine, low-caffeine green tea, on stress and sleep of the elderly. The participants (n = 10, mean age 89.3 ± 4.2 years) drank five cups/day of standard green tea for 1 week. Subsequently, they drank five cups/day of low-caffeine green tea for 2 weeks. Salivary α-amylase activity (sAA) was measured as a stress marker. Sleep stages were measured using a portable electroencephalography (n = 7, 6 female and 1 male). The level of sAA in the morning (sAAm) was significantly lower when the participants drank low-caffeine green tea than standard green tea. While the levels of sAAm were different among individuals, lower sAAm correlated with a higher quality of sleep. In those participants whose sAAm was lowered by the ingestion of low-caffeine green tea, some sleep parameters improved. Daily ingestion of low-caffeine green tea may be a beneficial tool for improving the quality of sleep of the elderly via the suppression of stress, although further research is required to fortify this hypothesis.

著者

Ai YOTO Tsuyoshi MORIYAMA Hidehiko YOKOGOSHI Yoriyuki NAKAMURA Tsuyoshi KATSUNO Tsutomu NAKAYAMA

出版者

日本感性工学会

雑誌

International Journal of Affective Engineering (ISSN:21875413)

巻号頁・発行日

vol.13, no.4, pp.227-233, 2014 (Released:2014-12-25)

参考文献数

23

被引用文献数

7

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We investigated the memory task performance and the central nervous activity after smelling two kinds of pan-fired Japanese green tea to examine their physical and psychological effects. Twenty eight subjects participated in this study. We used Koushun and Kouju for test samples, which were made by different manufacturing processes. After smelling each odor sample, a memory task and an arithmetic task were used to test mental stress. Electroencephalogram (EEG) was recorded before and after smelling the test samples, and EEG activity was estimated for 4 frequency bands (alpha 1, alpha 2, beta 1 and beta 2). The profiles of mood states (POMS) and the visual analog scale (VAS) after mental stress task were completed for subjective assessments. The results showed that the odor of Kouju may induce a positive emotion. It may also affect the EEG band power of beta 1 at right frontal region and improve memory task performance.