Green Tea Anticancer Mechanisms in Smokers
The purpose of this study is to determine whether green tea may lower the risk of certain cancers.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Subject)
Primary Purpose: Prevention
|Official Title:||Green Tea Anticancer Mechanisms in Smokers|
- Antioxidant effects of green tea versus placebo consumption. [ Time Frame: Measured at post treatment ] [ Designated as safety issue: No ]Examine antioxidant effects of green tea versus placebo by measuring scavenging of free radicals; tea flavonoids; inflammatory cell secretion; endogenous antioxidant glutathione.
- Non-antioxidant, cancer-relevant effects of green tea consumption [ Time Frame: Measured at pre-treatment and post treatment ] [ Designated as safety issue: No ]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 Start Date:||June 2010|
|Study Completion Date:||August 2013|
|Primary Completion Date:||August 2013 (Final data collection date for primary outcome measure)|
Experimental: Green Tea
4 cups daily of green tea for 6 weeks
Dietary Supplement: Green Tea
Green Tea 4 cups daily
Placebo Comparator: No Green Tea
4 cups daily of placebo tea for 6 weeks
4 cups placebo tea for 6 weeks
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.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01162642
|United States, Ohio|
|The Ohio State University|
|Columbus, Ohio, United States, 43210|
|Principal Investigator:||Philip Diaz, M.D.||Ohio State University|