Anti-stress Effect of Green Tea with Lowered Caffeine on Humans: A Pilot Study.
Biol Pharm Bull
; 40(6): 902-909, 2017.
Article
em En
| MEDLINE
| ID: mdl-28566632
ABSTRACT
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).
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estresse Psicológico
/
Chá
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Ansiolíticos
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Cafeína
Tipo de estudo:
Clinical_trials
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
Biol Pharm Bull
Assunto da revista:
BIOQUIMICA
/
FARMACOLOGIA
Ano de publicação:
2017
Tipo de documento:
Article