The verification study of improvements in psychological stress with intake of black tea extract supplements: a randomized double-blind placebo-controlled crossover trial

The verification study of improvements in psychological stress with intake of black tea extract supplements: a randomized double-blind placebo-controlled crossover trial - The verification study of improvements in psychological stress with intake of black tea extract supplements

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000027549

Enrollment

Registered

2017-09-01

Start date

2017-03-21

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy adults

Interventions

Duration: 3 weeks Test material: The powder of extracted Uva tea Dose: Take 4 capsules, three times a day (1 capsule for 200 mg) Administrative: Take 4 capsules before each meal *If you forget to

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Those who feel stress in daily 2. Healthy Japanese adults 3. Those who are considered to appropriate for the study by the physician 4. Those who have relatively high difference between age of autonomic nervous function and their actual age

Exclusion criteria

Exclusion criteria: 1. Medical history of a malignant tumor, heart failure or myocardial infarction 2. Those who are receiving treatment or having medical history for any of the following chronic diseases: cardiac arrhythmia, hepatic disorder, renal disorder, cerebrovascular disorder, rheumatism, diabetes mellitus, dyslipidemia, hypertension or any other chronic diseases 3. Daily use of Food for Specified Health Uses and/or Foods with Functional Claims 4. Those who currently take medicines (include herbal medicines) and/or supplements 5. Those who are allergic to medicines and/or the test food related products 6. Those who have taken caffeine and have become sick 7. Those who are pregnant, breast-feeding, or are expected to become pregnant during the trial period 8. Another clinical test participant within three months before the informed consent form submission 9. Others assessed as inappropriate for this test by the doctor responsible for the test

Design outcomes

Primary

Measure	Time frame
autonomic function test 1. low frequency (LF) 2. high frequency (HF) 3. LF/HF 4.autonomic function age subjective symptoms 1. profile of Mood States 2nd edition (POMS2) Japanese version	—

Secondary

Measure	Time frame
1. salivary alpha-amylase activity 2. cortisol activity	—

Countries

Japan

Contacts

Public ContactNaoko SUZUKI

ORTHOMEDICO Inc. R&D Department

nao@orthomedico.jp03-3818-0610

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026