Evidence map›Paper›PMID 41772671›Full record

ArticleGenes and environment : the official journal of the Japanese Environmental Mutagen Society2026

Potential of green tea extract to suppress colorectal polyp development in patients with familial adenomatous polyposis: a double-blind, randomized controlled trial Japan Familial Adenomatous Polyposis Prevention Study (J-FAPP Study I).

Hideki Ishikawa, Michihiro Mutoh, Tetsuro Yamane, Keiji Wakabayashi, Keiji Hirata, Takeo Iwama, Tomiyo Nakamura, Naohiro Tomita, Yutaka Matsuyama, J-FAPP Study I Group

Abstract read
In one paragraph

Article in Genes and environment : the official journal of the Japanese Environmental Mutagen Society, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from 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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors.

Hideki IshikawaDepartment of Molecular-Targeting Prevention, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Michihiro MutohDepartment of Molecular-Targeting Prevention, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan. mimutoh@koto.kpu-m.ac.jp.
Tetsuro YamaneMatsushita Memorial Hospital, Kyoto, Japan.
Keiji WakabayashiGraduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
Keiji HirataDepartment of Surgery 1, University of Occupational and Environmental Health, Kitakyushu, Japan.
Takeo IwamaThe Department of Digestive Tract and General Surgery, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
Tomiyo NakamuraResearch Institute for Food and Agriculture, Ryukoku University, Kyoto, Japan.
Naohiro TomitaDivision of Cancer Treatment, Toyonaka Municipal Hospital, Osaka, Japan.
Yutaka MatsuyamaDepartment of Biostatistics, School of Public Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
J-FAPP Study I Group

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundFamilial adenomatous polyposis (FAP) is an autosomal dominantly inherited disease that results in the development of more than 100 polyps, premalignant lesions, in the colorectum. Therefore, patients with FAP are a high-risk group for colorectal cancer (CRC). The only standard method of preventing CRC is total colectomy. Thus, alternative methods to prevent the development of CRC are desired by patients. Epidemiological and animal studies suggested that green tea and its extracts, such as (−)-epigallocatechin gallate, may have the potential to prevent cancer development.

resultsIn the present study, we evaluated the suppressive effects of green tea extract (GTE) on suppress colorectal polyps in FAP and conducted a double-blind clinical trial. Eighty patients were randomly assigned to the GTE group (1.5 g/day for 2 years) and an equal number were assigned to the placebo group. The primary endpoint of colon polyp enlargement tended to be reduced in the GTE group compared with the placebo group, with a risk ratio of 0.43 (95% confidence interval 0.12–1.49; p = 0.16).

conclusionsGiven that the risk ratio was less than 0.5 and few adverse events were observed, we believe that further research using GTE after calculating the necessary sample size is calculated on the based of this study, should be considered in a future large-scale clinical trial.

Indexed as

ChemopreventionFamilial adenomatous polyposisGreen tea extractRandomized controlled trial

Identifiers

PMID41772671
PMCPMC12958651

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.