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High Tea Consumption on Smoking Related Oxidative Stress

A Chemoprevention Trial to Study the Effects of High Tea Consumption on Smoking Related Oxidative Stress

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02719860
Enrollment
154
Registered
2016-03-25
Start date
2003-09-30
Completion date
2007-12-31
Last updated
2016-03-25

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

Conditions

Lung Cancer Prevention

Brief summary

The overall objective of this study is to determine the effect of high tea consumption on biological markers of oxidative stress that mediate lung cancer risk.

Interventions

DIETARY_SUPPLEMENTGreen tea

4 cups/day of green tea for 6 months; each cup is prepared by brewing 2 tea bags in 12 oz of water

DIETARY_SUPPLEMENTBlack tea

4 cups/day of black tea for 6 months; each cup is prepared by brewing 2 tea bags in 12 oz of water

DIETARY_SUPPLEMENTPlacebo tea

4 cups/day of placebo tea for 6 months; each cup is prepared by brewing 2 tea bags in 12 oz of water

Sponsors

United States Department of Defense
CollaboratorFED
University of Arizona
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE

Eligibility

Sex/Gender
ALL
Age
40 Years to 80 Years

Inclusion criteria

* FEV1 \< 85% and at least 25 pack-years of current or former smoking history. * No diagnosis of internal cancer within the last 5 years or no chemotherapy or radiation for an internal cancer within the last 5 years. * Meets the Southwest Oncology Group (SWOG) performance status criteria of 0-1. * Not be pregnant or intending to get pregnant during the study period (women participants). * Willing to drink 4 cups of tea (each cup will be brewed with 2 tea bags and 12 ounces of water) for 1-month run-in period and for the 6-month intervention period. * Willing to refrain from consuming other tea or tea products starting one month before the placebo run-in period and for the entire study period (a total of 8 months) * Willing to refrain from consuming more than one caffeinated product (coffee, soda..) starting one month before the placebo run-in period and for the entire study period (a total of 8 months). * Subjects cannot take mega-doses of vitamins during the trial. This is defined as more than 400 IU of vitamin E, 200 ug of selenium, or 1 gm of vitamin C per day, or more than the tolerable upper limits of any other supplement as defined in the Dietary Reference Intake panels developed by the Food and Nutrition Board under the Institute of Medicine. Such vitamin therapy must be discontinued at least 2 weeks prior to study entry.

Exclusion criteria

* Subjects immunosuppressed by virtue of medication or disease. * Serious concurrent illness that could interfere with study regimen. * Subjects with a history of invasive cancer within the past 5 years. * Subjects who are drinking more than 5 cups of non-herbal tea per week. * Subjects who cannot or are unwilling to consume caffeinated beverages. * Subjects unable to perform forced expiratory maneuver during spirometry testing. * More than one acute emphysema exacerbation within the last 6 month -period . * Subjects on oxygen. * Women with positive urinary pregnancy test.

Design outcomes

Primary

MeasureTime frame
Post-intervention change in urinary 8-hydroxydeoxyguanosineBaseline and 6 months
Post-intervention change in urinary 8-F2-isoprostanesBaseline and 6 months

Outcome results

None listed

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