Study Results
Outcome measurements, participant flow, baseline characteristics, and adverse events have been published for this study.
View full resultsBasic Information
Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.
COMPLETED
PHASE2
1075 participants
INTERVENTIONAL
2009-07-31
2014-06-30
Brief Summary
Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.
PURPOSE: This phase II trial is studying how well green tea extract works in preventing breast cancer compared to a placebo in postmenopausal women with high breast density.
The investigators have hypothesized that green tea consumption reduces breast cancer risk, and this effect is seen primarily in women who have the low-activity COMT genotype. The investigators will test this by evaluating the effects of green tea extract on breast cancer biomarkers including mammographic density, plasma insulin-like growth factor 1 (IGF-1), IGF binding protein 3 (IGFBP-3), estrone, estradiol, androstenedione, sex hormone binding globulin (SHBG), urinary estrogen metabolites and plasma F2-isoprostanes.
Related Clinical Trials
Explore similar clinical trials based on study characteristics and research focus.
Green Tea Anticancer Mechanisms in Smokers
NCT01162642
High Tea Consumption on Smoking Related Oxidative Stress
NCT02719860
Effects of Green Tea on Cardiometabolic Outcomes
NCT06795438
Effects of Green Coffee Extract Supplementation on Adropin, Irisin, Vaspine,Systemic Inflammation and Oxidative Stress in Breast Cancer Survivors
NCT03395561
Effects of Green Tea Extract on Obese Women With High Level of LDL
NCT02116517
Detailed Description
Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.
1. Primary:
1.1 To determine the effects of green tea extract consumption (containing 800 mg EGCG per day) for 12 months on the following recognized biomarkers of breast cancer risk:
1. Mammographic density
2. Circulating concentrations of insulin-like growth factor 1 (IGF-1) and IGF binding protein 3 (IGFBP-3)
3. Circulating concentrations of reproductive hormones (estrone, estradiol, androstenedione) and sex hormone binding globulin (SHBG)
1.2 To determine the effects of COMT genotype on the green tea extract effects described above.
2. Secondary:
2.1 To determine the effects of green tea extract consumption (containing 800 mg EGCG per day) for 12 months on the following hypothesized biomarkers of breast cancer risk:
1. Urinary estrogen metabolites (estrone, estradiol, and their 2-hydroxy, 4-hydroxy, 2-methoxy, and 4-methoxy metabolites, estriol, and 16- hydroxyestrone)
2. Circulating concentrations of F-2 isoprostanes, a recognized biomarker of systemic oxidative stress
2.2 To determine the effects of COMT genotype on the green tea extract effects described above.
2.3 To determine the effects of COMT genotype on catechin metabolism and excretion, as measured by circulating and urinary concentrations.
Conditions
See the medical conditions and disease areas that this research is targeting or investigating.
Study Design
Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.
RANDOMIZED
PARALLEL
PREVENTION
QUADRUPLE
Study Groups
Review each arm or cohort in the study, along with the interventions and objectives associated with them.
Green tea extract
Green tea extract capsules containing 80.7 % total catechins (51.7 % EGCG)
Green tea extract supplement
Two green tea extract capsules twice daily after breakfast and dinner for one year
Sugar pill
Placebo capsules containing 50% maltodextrin, 49.5 % cellulose, and 0.5 % magnesium stearate
Placebo
Two placebo capsules twice daily after breakfast and dinner for one year
Interventions
Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.
Green tea extract supplement
Two green tea extract capsules twice daily after breakfast and dinner for one year
Placebo
Two placebo capsules twice daily after breakfast and dinner for one year
Other Intervention Names
Discover alternative or legacy names that may be used to describe the listed interventions across different sources.
Eligibility Criteria
Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.
Inclusion Criteria
* Healthy postmenopausal women aged 50-70 years
* "Heterogeneously dense" (51-75% glandular) or "extremely dense" (\>75%glandular) breasts
* Willing to avoid consumption of green tea for 1 year
Exclusion Criteria
* Elevated levels of liver enzymes
* Recent (within 6 mo) or current hormone or hormone modification therapy, including systemic hormone replacement therapy, SERMS and aromatase inhibitors
* Current smoker of cigarettes or other tobacco products
* BMI \<19 or \>40 kg/m2
* Weight change \> 10 lbs during the previous year
* History of breast cancer or proliferative breast disease
* Regular consumption of \> 7 alcoholic drinks/wk
* Regular consumption of green tea (\>1 cup/wk)
* Recent (within 6 mo) or current use of chemopreventive agents such as tamoxifen, raloxifene or aromatase inhibitors
* Participation in any weight loss or weight gain studies
* Currently taking Methotrexate or Enbrel
* History of ovarian cancer
* Any form of cancer in the last 5 years
* Presence of implants
50 Years
70 Years
FEMALE
Yes
Sponsors
Meet the organizations funding or collaborating on the study and learn about their roles.
National Cancer Institute (NCI)
NIH
University of Minnesota
OTHER
Responsible Party
Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.
Principal Investigators
Learn about the lead researchers overseeing the trial and their institutional affiliations.
Mindy S Kurzer, Ph.D
Role: PRINCIPAL_INVESTIGATOR
University of Minnesota
Locations
Explore where the study is taking place and check the recruitment status at each participating site.
Fairview Southdale Breast Center
Edina, Minnesota, United States
Fairview Maple Grove Breast Center
Maple Grove, Minnesota, United States
University of Minnesota Medical Center (UMMC) Breast Clinic
Minneapolis, Minnesota, United States
Park Nicollet Institute
Saint Louis Park, Minnesota, United States
Food Science and Nutrition, University of Minnesota
Saint Paul, Minnesota, United States
Countries
Review the countries where the study has at least one active or historical site.
References
Explore related publications, articles, or registry entries linked to this study.
Bathgate JR, Radler DR, Kurzer M, Samavat H. Green tea extract supplementation does not modify plasma concentration of F2-isoprostanes in women who are postmenopause: Findings from a randomized controlled trial. Nutr Res. 2023 May;113:29-38. doi: 10.1016/j.nutres.2023.03.001. Epub 2023 Mar 9.
Samavat H, Wu AH, Ursin G, Torkelson CJ, Wang R, Yu MC, Yee D, Kurzer MS, Yuan JM. Green Tea Catechin Extract Supplementation Does Not Influence Circulating Sex Hormones and Insulin-Like Growth Factor Axis Proteins in a Randomized Controlled Trial of Postmenopausal Women at High Risk of Breast Cancer. J Nutr. 2019 Apr 1;149(4):619-627. doi: 10.1093/jn/nxy316.
Arikawa AY, Samavat H, Gross M, Kurzer MS. Plasma F2-isoprostanes Are Positively Associated with Glycemic Load, but Inversely Associated with Dietary Polyunsaturated Fatty Acids and Insoluble Fiber in Postmenopausal Women. J Nutr. 2017 Sep;147(9):1693-1699. doi: 10.3945/jn.117.254631. Epub 2017 Jul 26.
Samavat H, Newman AR, Wang R, Yuan JM, Wu AH, Kurzer MS. Effects of green tea catechin extract on serum lipids in postmenopausal women: a randomized, placebo-controlled clinical trial. Am J Clin Nutr. 2016 Dec;104(6):1671-1682. doi: 10.3945/ajcn.116.137075. Epub 2016 Nov 2.
Dostal AM, Arikawa A, Espejo L, Kurzer MS. Long-Term Supplementation of Green Tea Extract Does Not Modify Adiposity or Bone Mineral Density in a Randomized Trial of Overweight and Obese Postmenopausal Women. J Nutr. 2016 Feb;146(2):256-64. doi: 10.3945/jn.115.219238. Epub 2015 Dec 23.
Dostal AM, Samavat H, Espejo L, Arikawa AY, Stendell-Hollis NR, Kurzer MS. Green Tea Extract and Catechol-O-Methyltransferase Genotype Modify Fasting Serum Insulin and Plasma Adiponectin Concentrations in a Randomized Controlled Trial of Overweight and Obese Postmenopausal Women. J Nutr. 2016 Jan;146(1):38-45. doi: 10.3945/jn.115.222414. Epub 2015 Nov 18.
Related Links
Access external resources that provide additional context or updates about the study.
The Minnesota Green Tea Trial (MGTT), a randomized controlled trial of the efficacy of green tea extract on biomarkers of breast cancer risk: study rationale, design, methods, and participant characteristics
The safety of green tea extract supplementation in postmenopausal women at risk for breast cancer: results of the Minnesota Green Tea Trial
Other Identifiers
Review additional registry numbers or institutional identifiers associated with this trial.
0806M36121
Identifier Type: -
Identifier Source: org_study_id
More Related Trials
Additional clinical trials that may be relevant based on similarity analysis.