Green tea extracts for the prevention of metachronous colorectal polyps among patients who underwent endoscopic removal of colorectal adenomas: A randomized clinical trial

Clin Nutr. 2018 Apr;37(2):452-458. doi: 10.1016/j.clnu.2017.01.014. Epub 2017 Jan 29.


Objectives: To determine the preventive effect of green tea extract (GTE) supplements on metachronous colorectal adenoma and cancer in the Korean population.

Materials and methods: One hundred seventy-six subjects (88 per each group) who had undergone complete removal of colorectal adenomas by endoscopic polypectomy were enrolled. They were randomized into 2 groups: supplementation group (0.9 g GTE per day for 12 months) or control group without GTE supplementation. The 72-h recall method was used to collect data on food items consumed by participants at baseline and the 1-year follow-up during the past 48 h. Follow-up colonoscopy was conducted 12 months later in 143 patients (71 in control group and 72 in the GTE group).

Results: Of the 143 patients completed in the study, the incidences of metachronous adenomas at the end-point colonoscopy were 42.3% (30 of 71) in control group and 23.6% (17 of 72) in GTE group (relative risk [RR], 0.56; 95% confidence interval [CI], 0.34-0.92). The number of relapsed adenoma was also decreased in the GTE group than in the control group (0.7 ± 1.1 vs. 0.3 ± 0.6, p = 0.010). However, there were no significant differences between the 2 groups in terms of body mass index, dietary intakes, serum lipid profiles, fasting serum glucose, and serum C-reactive protein levels (all p > 0.05).

Conclusion: This study of GTE supplement suggests a favorable outcome for the chemoprevention of metachronous colorectal adenomas in Korean patients ( number, NCT02321969).

Keywords: Colon polyps; Epigallocatechin gallate; Green tea; Recurrence risk.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / surgery*
  • Adult
  • Aged
  • Aged, 80 and over
  • Antioxidants / therapeutic use
  • Colonic Polyps / prevention & control*
  • Colonoscopy / methods*
  • Colorectal Neoplasms / surgery*
  • Female
  • Humans
  • Korea
  • Male
  • Middle Aged
  • Plant Extracts / therapeutic use*
  • Prospective Studies
  • Tea*
  • Treatment Outcome
  • Young Adult


  • Antioxidants
  • Plant Extracts
  • Tea

Associated data