title: Green tea extracts for the prevention of metachronous colorectal adenomas: a pilot study.
abstract: BACKGROUND
  Experimental studies indicate the chemopreventive properties of green tea extract (GTE) on colorectal cancer. Epidemiologically, green tea consumption of > 10 cups daily reduced colorectal cancer risk in Japanese. Because colorectal adenomas are the precursors to most sporadic colorectal cancers, we conducted a randomized trial to determine the preventive effect of GTE supplements on metachronous colorectal adenomas by raising green tea consumption in the target population from an average of 6 cups (1.5 g GTE) daily to > or = 10 cups equivalent (2.5 g GTE) by supplemental GTE tablets.
  
  
  METHODS
  We recruited 136 patients, removed their colorectal adenomas by endoscopic polypectomy, and 1 year later confirmed the clean colon (i.e., no polyp) at the second colonoscopy. The patients were then randomized into two groups while maintaining their lifestyle on green tea drinking: 71 patients supplemented with 1.5 g GTE per day for 12 months and 65 control patients without supplementation. Follow-up colonoscopy was conducted 12 months later in 125 patients (65 in the control group and 60 in the GTE group).
  
  
  RESULTS
  The incidence of metachronous adenomas at the end-point colonoscopy was 31% (20 of 65) in the control group and 15% (9 of 60) in the GTE group (relative risk, 0.49; 95% confidence interval, 0.24-0.99; P < 0.05). The size of relapsed adenomas was also smaller in the GTE group than in the control group (P < 0.001). No serious adverse events occurred in the GTE group.
  
  
  CONCLUSIONS
  GTE is an effective supplement for the chemoprevention of metachronous colorectal adenomas.
authors.affiliation: Department of Medicine, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Shimizu
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Fukutomi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ninomiya
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nagura
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kato
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Araki
authors.forename: Masami
authors.initials: M
authors.lastname: Suganuma
authors.forename: Hirota
authors.initials: H
authors.lastname: Fujiki
authors.forename: Hisataka
authors.initials: H
authors.lastname: Moriwaki
mesh_terms: D000236:Adenoma / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000517:prevention & control*; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000517:prevention & control*; D010865:Pilot Projects; D010936:Plant Extracts; D013662:Tea; D016896:Treatment Outcome
chemical_list: D010936:Plant Extracts; D013662:Tea