Effects of Tea Catechin Extracts on Oxidative Damage

Effects of Tea Catechin Extracts on the Frequency Changes of Micronuclei in Peripheral Lymphocytes in Late Middle Aged Healthy Volunteers

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00448513

Enrollment

Registered

2007-03-19

Start date

2007-06-30

Completion date

2012-04-30

Last updated

2013-07-16

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

Conditions

Healthy

Keywords

catechin, oxidative stress, chromosome damage, aged

Brief summary

The purpose of this study is to clarify the effects of tea catechin extracts on the frequency changes of micronuclei in peripheral lymphocytes compared with other oxidative stress markers in late middle aged healthy volunteers

Detailed description

Experimental studies have revealed that tea catechin extracts induce preventive effects on oxidative stress, but there have been few clinical trials conducted to verify the effects. Also, there have been few clinical markers indicating oxidative damage, and therefore, more accurate and reliable markers have been expected. The study is designed for evaluating the effects of tea catechin extracts on the frequency changes of micronuclei in peripheral lymphocytes as the indicator of oxidative damage, compared with other oxidative stress markers in late middle aged healthy volunteers.

Interventions

DIETARY_SUPPLEMENTcatechin extracts

comparison with placebo

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

PREVENTION

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

40 Years to 65 Years

Healthy volunteers

Yes

Inclusion criteria

* aged 40 to 65 years old * healthy volunteers * obtained written informed concent before participation

Exclusion criteria

* participant who is not able to refrain from drinking tea for 2 weeks during the study * participant taking supplements or herbal products including folate, vitamin B, C, E, coenzyme Q10, calcium, for 2 weeks before the study * participant taking supplements or herbal products including folate, vitamin E for 3 months before the study * participant possessing tea allergy

Design outcomes

Primary

Measure	Time frame
the frequency changes of micronuclei in peripheral lymphocytes	After seven days untervention

Secondary

Measure	Time frame
the change of markers of oxidative damage, as measured by 8-hydroxyguanosine (8-OHdG), vitamin C, folate, homocysteine	After seven days intervention

Countries

Japan

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026