Trial reportCancer causes & control : CCC2015
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.
Trial report in Cancer causes & control : CCC, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 28 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
28 citing papers in PubMed, 2 syntheses or guidelines pooled it, 43 citations in OpenAlex.
- Green tea (Camellia sinensis) for the prevention of cancer.The Cochrane database of systematic reviews · 2020Pooled it
- Green Tea Consumption and Risk of Breast Cancer and Recurrence-A Systematic Review and Meta-Analysis of Observational Studies.Nutrients · 2018Pooled it
- Trial
- Green tea extract supplementation does not modify plasma concentration of FNutrition research (New York, N.Y.) · 2023Trial
- Hepatotoxicity with High-Dose Green Tea Extract: Effect ofJournal of dietary supplements · 2023Trial
- 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.The Journal of nutrition · 2019Trial
- Quality of life among postmenopausal women enrolled in the Minnesota Green Tea Trial.Maturitas · 2018Trial
- A Randomized Controlled Trial of Green Tea Extract Supplementation and Mammographic Density in Postmenopausal Women at Increased Risk of Breast Cancer.Cancer prevention research (Philadelphia, Pa.) · 2017Trial
- Effect of Green Tea Supplements on Liver Enzyme Elevation: Results from a Randomized Intervention Study in the United States.Cancer prevention research (Philadelphia, Pa.) · 2017Trial
- Plasma FThe Journal of nutrition · 2017Trial
- Green tea extract and catechol-O-methyltransferase genotype modify the post-prandial serum insulin response in a randomised trial of overweight and obese post-menopausal women.Journal of human nutrition and dietetics : the official journal of the British Dietetic Association · 2017Trial
- Effects of green tea catechin extract on serum lipids in postmenopausal women: a randomized, placebo-controlled clinical trial.The American journal of clinical nutrition · 2016Trial
- 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.The Journal of nutrition · 2016Trial
- 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.The Journal of nutrition · 2016Trial
- Chemopreventive and therapeutic effects ofFrontiers in pharmacology · 2025Article
- Exploration of plasma adiponectin, leptin, andJournal of nutritional science · 2023Article
- Health Effects of Soy Isoflavones and Green Tea Catechins on Cancer and Cardiovascular Diseases Based on Urinary Biomarker Levels.Molecules (Basel, Switzerland) · 2022Review
- Article
- Associations between Polymorphisms in Phase II Enzymes and Circulating Sex-Steroid Hormones in White Postmenopausal Women.Journal of menopausal medicine · 2021Article
- Associations between Diet Quality and Anthropometric Measures in White Postmenopausal Women.Nutrients · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
15 authors at 7 institutions in 2 countries.
Funding
Abstract
purposeThe Minnesota Green Tea Trial (MGTT) was a randomized, placebo-controlled, double-blinded trial investigating the effect of daily green tea extract consumption for 12 months on biomarkers of breast cancer risk.
methodsParticipants were healthy postmenopausal women at high risk of breast cancer due to dense breast tissue with differing catechol-O-methyltransferase (COMT) genotypes. The intervention was a green tea catechin extract containing 843.0 ± 44.0 mg/day epigallocatechin gallate or placebo capsules for 1 year. Annual digital screening mammograms were obtained at baseline and month 12, and fasting blood and 24-h urine samples were provided at baseline and at months 6 and 12. Primary endpoints included changes in percent mammographic density, circulating endogenous sex hormones, and insulin-like growth factor axis proteins; secondary endpoints were changes in urinary estrogens and estrogen metabolites and circulating F2-isoprostanes, a biomarker of oxidative stress.
resultsThe MGTT screened more than 100,000 mammograms and randomized 1,075 participants based on treatment (green tea extract vs. placebo), stratified by COMT genotype activity (high COMT vs. low/intermediate COMT genotype activity). A total of 937 women successfully completed the study and 138 dropped out (overall dropout rate = 12.8 %).
conclusionsIn this paper we report the rationale, design, recruitment, participant characteristics, and methods for biomarker and statistical analyses.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.