Expired Study
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Columbus, Ohio 43210


The purpose of this study is to determine whether green tea may lower the risk of certain cancers.

Study summary:

Green tea contains phytochemicals, especially flavonoids. Phytochemicals are not absolutely required for normal functions, but may confer health benefits such as antioxidant actions. One can live without phytochemicals, but one may live longer and better with them. The phytochemicals in tea have been proposed to inhibit cancer onset via several different mechanisms. An obvious question is: Can anti-cancer actions of green tea be duplicated by black tea, which in the USA, is consumed more than green tea? The question remains unanswered, and will not be addressed by this project since many questions about green tea have not been answered yet. The contents of both type teas overlap in flavonoids, but green tea has more of the agents thought to be most effective. For example, some of the research cited below uses the flavonoid epigallocatechin gallate. Green tea has 5 times more of this flavonoid than black tea. This study has two purposes. First, a case will be made that green tea may have several anti-cancer mechanisms, but this contention is not well confirmed by human intervention studies. This case will be made by addressing four questions. Second, justification will be given for the choice of mechanisms to be examined in this project's human intervention.


Inclusion Criteria: - Healthy 23-40 year old males and non-pregnant females, who are moderately heavy smokers (1-1.75 packs/day, > 2 years) Exclusion Criteria: - Habitual tea intake - Habitual flavonoid supplementation - Soy product intake over twice a week (soy is high in flavonoids). - Pulmonary diseases - Chronic or acute infection - Admission of heavy alcohol intake (> 14 beers or drinks a week) - Body mass index (BMI) > 30 (moderately overweight subjects will be taken) - Abnormal EKG - History of heart or other major health problems (ie arthritis, diabetes). - Subjects with slightly high blood pressure will be eligible for the project, but more severe hypertension (>150/100)

Study is Available At:

Original ID:




Secondary ID:

Study Acronym:

Brief Title:

Green Tea Anticancer Mechanisms in Smokers

Official Title:

Green Tea Anticancer Mechanisms in Smokers

Overall Status:


Study Phase:




Minimum Age:

23 Years

Maximum Age:

40 Years

Quick Facts

Healthy Volunteers
Oversight Has DMC
Study Is FDA Regulated
Study Is Section 801
Has Expanded Access

Study Source:

Ohio State University

Oversight Authority:

United States: Institutional Review Board

Reasons Why Stopped:

Study Type:


Study Design:

Allocation: Randomized, Endpoint Classification: E

Number of Arms:


Number of Groups:


Total Enrollment:


Enrollment Type:


Overall Contact Information

Official Name:Philip Diaz, M.D.
Principal Investigator
Ohio State University

Study Dates

Start Date:June 2010
Completion Date:August 2013
Completion Type:Actual
Primary Completion Date:August 2013
Primary Completion Type:Actual
Verification Date:April 2015
Last Changed Date:April 20, 2015
First Received Date:June 23, 2010

Study Outcomes

Outcome Type:Primary Outcome
Measure:Antioxidant effects of green tea versus placebo consumption.
Time Frame:Measured at post treatment
Safety Issues:False
Description:Examine antioxidant effects of green tea versus placebo by measuring scavenging of free radicals; tea flavonoids; inflammatory cell secretion; endogenous antioxidant glutathione.
Outcome Type:Secondary Outcome
Measure:Non-antioxidant, cancer-relevant effects of green tea consumption
Time Frame:Measured at pre-treatment and post treatment
Safety Issues:False
Description:Examine non-antioxidant, cancer-relevant effects of green tea by measuring NF-kappaB inducing kinase; phosphorylation of cell signaling agents; tumor necrosis factor gene expression; lysyl oxidase enzyme; blockage of cancer cell proliferation.

Study Interventions

Intervention Type:Dietary Supplement
Name:Green Tea
Description:Green Tea 4 cups daily
Arm Name:Green Tea
Intervention Type:Other
Description:4 cups placebo tea for 6 weeks
Arm Name:No Green Tea

Study Arms

Study Arm Type:Experimental
Arm Name:Green Tea
Description:4 cups daily of green tea for 6 weeks
Study Arm Type:Placebo Comparator
Arm Name:No Green Tea
Description:4 cups daily of placebo tea for 6 weeks

Study Agencies

Agency Class:Other
Agency Type:Lead Sponsor
Agency Name:Philip Diaz

Sample and Retention Information

There are no available Sample and Retention Information

Study References

There are no available Study References

Data Source: ClinicalTrials.gov

Date Processed: October 09, 2019

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