Effect of low-caffeine green tea against sleep and stress in the middle-aged people
- Conditions
- Sleep, Stress
- Registration Number
- JPRN-UMIN000019411
- Lead Sponsor
- niversity of Shizuoka
- Brief Summary
We examined the effects of green tea with lowered caffeine content (LCGT) on stress and quality of sleep of middle-aged individuals (n=20) in a double-blind crossover design. Standard green tea (SGT) was used as the control. The level of salivary amylase activity (sAA), a stress marker, was significantly lower in participants that consumed LCGT than in those that consumed SGT. Sleep quality was higher in participants that consumed a larger quantity of LCGT. In addition, a self-diagnostic check for accumulated fatigue was significantly lower in those participants that consumed LCGT than SGT. These results indicate that LCGT intake can reduce stress in middle-aged individuals and improve their quality of sleep. The reduction in caffeine is suggested to be a valid reason for enhancing the anti-stress effect of green tea.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Complete: follow-up complete
- Sex
- All
- Target Recruitment
- 20
Not provided
Taking sleep-inducing drug and tranquilized; Smoker; Diagnosed as inadequate to participate in the study by a doctor
Study & Design
- Study Type
- Interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method Alterations in brain waves and salivary amylase activity in the middle-aged people that drank green tea with lowered caffeine
- Secondary Outcome Measures
Name Time Method Physical condition, Sleeping time, Replying to a questionnaire (subjective stress)