Green tea extract to prevent colorectal adenomas in men and women: Results of the MIRACLE trial.

1551 Background: Prevention of colorectal adenomas (CA) can reduce colorectal cancers (CRC). Epidemiological and experimental data suggest that the green tea catechin epigallocatechingallate has an antineoplastic effect in the large bowel. MIRACLE is the largest trial so far to examine the effect of three-year daily intake of green tea extract (GTE) on the incidence of metachronous CA in a Caucasian population. Methods: Prospective, parallel group, double-blinded, placebo-controlled, randomized multicenter trial (40 German centers, recruitment 11/2011-6/2015). Patients (n = 1001, age 50-80y), polypectomy ≤ 6 months and tolerating GTE well (one-month run-in) were randomized to receive decaffeinated GTE standardized to EGCG (150 mg bid, capsules) or placebo (P) for 3 years. Primary endpoint: Incidence of metachronous CA at the 3-year follow-up colonoscopy. Secondary endpoints: Occurrence, number, localization, size, histological subtype of CA, frequency of CRC, biomarker and safety. Strata: study center, low-dose aspirin (≤100 mg/d). Results: Clinical parameters were well balanced. CA incidence at the 3-year follow-up colonoscopy was analyzed in the modified ITT set (modITT; n = 309 patients (GTE), n = 323 (placebo), timely follow up colonoscopy) and the per protocol set (PP, modITT set without major protocol violations). Incidence of CA was 55.7 % (P) and 51.1% (GTE), (modITT, adj. RR 0.905, one sided, p = 0.081), respectively 54.3 % (P) and 48.3% (GTE) (PP, adj. RR 0.883, one sided, p = 0.058). These differences did not reach statistical significance. In the preplanned exploratory analysis regarding gender incidence of CA in females was 47.9% (P) and 47.6% (GTE) in the modITT-set (adj. RR 0.989; 95%-CI: 0.753,1.299; p = 0.935), respectively 45.4% (P) and 46.9% (GTE) in the PP-set (adj. RR 1.014; 95%-CI: 0.748, 1.373; p = 0.930). In contrast, in the male population incidence of CA in the follow-up colonoscopy was 60.4% (P) and 52.9% (GTE) in the modITT-set (adj. RR 0.846; 95% CI 0.717, 0.999); p = 0.048), respectively 59.1% (P) and 49.1% (GTE) in the PP-set (RR 0.803, 95% CI: 0.666, 0.969; p = 0.022). Thus, GTE intake was associated with a significant, 12.4 relative and 7.5% absolute reduction of metachronous CA in the male modITT population. There were no differences with respect to safety between the groups. Conclusions: GTE reduced the incidence of metachronous CA. However, a significant effect was only observed in the in the male population whereas there was no effect in the female population. Clinical trial information: NCT 01360320.

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The MIRACLE trial: A randomized, controlled trial comparing green tea extract versus placebo for the prevention of metachronous colon adenomas in a screening population.

Journal of Clinical Oncology ◽

10.1200/jco.2015.33.3_suppl.tps786 ◽

2015 ◽

Vol 33 (3_suppl) ◽

pp. TPS786-TPS786 ◽

Cited By ~ 1

Author(s):

Thomas Jens Ettrich ◽

Julia Stingl ◽

Rainer Muche ◽

Katrin Claus ◽

Baerbel Reiser ◽

...

Keyword(s):

Green Tea ◽

Controlled Trial ◽

Epigallocatechin Gallate ◽

Genetic Alterations ◽

Colorectal Polyps ◽

Green Tea Extract ◽

Colorectal Adenomas ◽

Tissue Samples ◽

Increased Risk ◽

Tea Extract

TPS786 Background: Prevention of colorectal cancer is a major health care issue. After polypectomy there is an increased risk of polyp recurrence and various means of chemoprevention have been tried to prevent this. NSAIDs have been shown to be effective but confer side effects such as gastrointestinal bleeding. Nutraceuticals such as polyphenols from tea plants have demonstrated remarkable therapeutic and preventive effects in molecular, epidemiological and some clinical trials. However, their value in preventing colorectal polyps has not been demonstrated in a large, randomized trial. The beneficial safety profile of decaffeinated green tea extract and accumulating evidence of its cancer preventive potential justify and require, in our view, a validation of this compound for the nutriprevention of colorectal adenoma. Good accessibility and low costs might render this neutraceutical a top candidate for wider use as nutritional supplement in colon cancer prevention. Methods: Randomized, double blinded, placebo-controlled, multicenter trial. After a one month run-in period with verum, 918 patients (age: 50-80 years) who have undergone polypectomy within the last 6 months will be randomized to receive either decaffeinated green tea extract (containing 150 mg epigallocatechin gallate (EGCG) two times daily) or placebo over a period of three years. Primary outcome: Incidence of metachronous colorectal adenomas (tubulovillous, tubular, villous, serrated lesions) at the 3 year follow-up colonoscopy. Secondary outcomes: Occurrences, number, localization, size and histological subtypes of adenomas, frequency of colorectal carcinoma. In addition, genetic and biochemical biomarkers in blood samples and genetic alterations (Ras, B-raf, microRNAs) in tissue samples of adenomas will be analyzed (biobanking subprojects). Additionally, nutrikinetics and nutrigenetics of EGCG and other catechins will be assessed in healthy volunteers. Patient recruitment has started in November 2011. At September 2014, 785 patients were recruited and 651 patients were randomized. We expect the last patient out in Spring 2018. (Trial identifier NCT01360320) Clinical trial information: NCT01360320.

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The Peroxidation of Leukocytes Index Ratio Reveals the Prooxidant Effect of Green Tea Extract

Oxidative Medicine and Cellular Longevity ◽

10.1155/2016/9139731 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Ilaria Peluso ◽

Husseen Manafikhi ◽

Anna Raguzzini ◽

Yaroslava Longhitano ◽

Raffaella Reggi ◽

...

Keyword(s):

Sample Size ◽

Green Tea ◽

Statistical Significance ◽

Green Tea Extract ◽

Expert Committee ◽

Primary Role ◽

Antioxidant Defences ◽

Prooxidant Effect ◽

Tea Extract ◽

Index Ratio

Despite tea increased plasma nonenzymatic antioxidant capacity, the European Food Safety Administration (EFSA) denied claims related to tea and its protection from oxidative damage. Furthermore, the Supplement Information Expert Committee (DSI EC) expressed some doubts on the safety of green tea extract (GTE). We performed a pilot study in order to evaluate the effect of a single dose of two capsules of a GTE supplement (200 mg × 2) on the peroxidation of leukocytes index ratio (PLIR) in relation to uric acid (UA) and ferric reducing antioxidant potential (FRAP), as well as the sample size to reach statistical significance. GTE induced a prooxidant effect on leukocytes, whereas FRAP did not change, in agreement with the EFSA and the DSI EC conclusions. Besides, our results confirm the primary role of UA in the antioxidant defences. The ratio based calculation of the PLIR reduced the sample size to reach statistical significance, compared to the resistance to an exogenous oxidative stress and to the functional capacity of oxidative burst. Therefore, PLIR could be a sensitive marker of redox status.

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Green tea extract only affects markers of oxidative status postprandially: lasting antioxidant effect of flavonoid-free diet

British Journal Of Nutrition ◽

10.1079/bjn2002523 ◽

2002 ◽

Vol 87 (4) ◽

pp. 343-355 ◽

Cited By ~ 74

Author(s):

J. F. Young ◽

L. O. Dragsted ◽

J. Haraldsdóttir ◽

B. Daneshvar ◽

M. A. Kall ◽

...

Keyword(s):

Antioxidant Capacity ◽

Green Tea ◽

Plasma Lipids ◽

Daily Intake ◽

Oxidative Status ◽

Green Tea Extract ◽

Long Term Effects ◽

Plasma Antioxidant Capacity ◽

Tea Extract ◽

Plasma Antioxidant

Epidemiological studies suggest that foods rich in flavonoids might reduce the risk of cardiovascular disease and cancer. The objective of the present study was to investigate the effect of green tea extract (GTE) used as a food antioxidant on markers of oxidative status after dietary depletion of flavonoids and catechins. The study was designed as a 2×3 weeks blinded human cross-over intervention study (eight smokers, eight non-smokers) with GTE corresponding to a daily intake of 18·6 mg catechins/d. The GTE was incorporated into meat patties and consumed with a strictly controlled diet otherwise low in flavonoids. GTE intervention increased plasma antioxidant capacity from 1·35 to 1·56 (P<0·02) in postprandially collected plasma, most prominently in smokers. The intervention did not significantly affect markers in fasting blood samples, including plasma or haemoglobin protein oxidation, plasma oxidation lagtime, or activities of the erythrocyte superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase. Neither were fasting plasma triacylglycerol, cholesterol, α-tocopherol, retinol, β-carotene, or ascorbic acid affected by intervention. Urinary 8-oxo-deoxyguanosine excretion was also unaffected. Catechins from the extract were excreted into urine with a half-life of less than 2 h in accordance with the short-term effects on plasma antioxidant capacity. Since no long-term effects of GTE were observed, the study essentially served as a fruit and vegetables depletion study. The overall effect of the 10-week period without dietary fruits and vegetables was a decrease in oxidative damage to DNA, blood proteins, and plasma lipids, concomitantly with marked changes in antioxidative defence.

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The MIRACLE trial: A randomized, controlled trial comparing green tea extract versus placebo for the prevention of metachronous colon adenomas in a screening population.

Journal of Clinical Oncology ◽

10.1200/jco.2012.30.15_suppl.tps1612 ◽

2012 ◽

Vol 30 (15_suppl) ◽

pp. TPS1612-TPS1612

Author(s):

Thomas Ettrich ◽

Julia Stingl ◽

Rainer Muche ◽

Andreas Berger ◽

Thomas Seufferlein

Keyword(s):

Green Tea ◽

Controlled Trial ◽

Epigallocatechin Gallate ◽

Genetic Alterations ◽

Colorectal Polyps ◽

Green Tea Extract ◽

Colorectal Adenomas ◽

Tissue Samples ◽

Increased Risk ◽

Tea Extract

TPS1612 Background: Prevention of colorectal cancer is a major health care issue. After polypectomy there is an increased risk of polyp recurrence and various means of chemoprevention have been tried to prevent this. NSAIDs have been shown to be effective but confer side effects such as gastrointestinal bleeding. Nutraceuticals such as polyphenols from tea plants have demonstrated remarkable therapeutic and preventive effects in molecular, epidemiological and some clinical trials. However, their value in preventing colorectal polyps has not been demonstrated in a large, randomized trial. The beneficial safety profile of decaffeinated green tea extract and accumulating evidence of its cancer preventive potential justify and require, in our view, a validation of this compound for the nutriprevention of colorectal adenoma. Good accessibility and low costs might render this neutraceutical a top candidate for wider use as nutritional supplement in colon cancer prevention. Methods: Randomized, double blinded, placebo-controlled, multicenter trial. After a one month run-in period with verum, 2534 patients (age: 50-80 years) who have undergone polypectomy within the last 6 months will be randomized to receive either decaffeinated green tea extract (containing 150 mg epigallocatechin gallate (EGCG) two times daily) or placebo over a period of three years. 2028 patients are expected to complete the whole study course. Primary outcome: Incidence of metachronous colorectal adenomas (tubulovillous, tubular, villous, serrated lesions) at the 3 year follow-up colonoscopy Secondary outcomes: Occurrences, number, localization, size and histological subtypes of adenomas, frequency of colorectal carcinoma. In addition, genetic and biochemical biomarkers in blood samples and genetic alterations (e.g. K-ras, B-raf, specific microRNAs) in tissue samples of adenomas will be analyzed (biobanking subprojects). Additionally, nutrikinetics and nutrigenetics of EGCG and other catechins will be assessed in healthy volunteers. Patient recruitment has started in November 2011. We expect the last patient out in fall 2017. (Trial identifier: NCT01360320)

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