title: Dietary polyphenols and colorectal cancer risk: the Fukuoka colorectal cancer study.
abstract: OBJECTIVE
  To investigate the associations between dietary intake of polyphenols and colorectal cancer.
  
  
  METHODS
  The study subjects were derived from the Fukuoka colorectal cancer study, a community-based case-control study. The study subjects were 816 cases of colorectal cancer and 815 community-based controls. The consumption of 148 food items was assessed by a computer-assisted interview. We used the consumption of 97 food items to estimate dietary intakes of total, tea and coffee polyphenols. The Phenol-Explorer database was used for 92 food items. Of the 5 foods which were not listed in the Phenol-Explorer Database, polyphenol contents of 3 foods (sweet potatoes, satoimo and daikon) were based on a Japanese study and 2 foods (soybeans and fried potatoes) were estimated by ORAC-based polyphenol contents in the United States Department of Agriculture Database. Odds ratios (OR) and 95%CI of colorectal cancer risk according to quintile categories of intake were obtained by using logistic regression models with adjustment for age, sex, residential area, parental history of colorectal cancer, smoking, alcohol consumption, body mass index 10 years before, type of job, leisure-time physical activity and dietary intakes of calcium and n-3 polyunsaturated fatty acids.
  
  
  RESULTS
  There was no measurable difference in total or tea polyphenol intake between cases and controls, but intake of coffee polyphenols was lower in cases than in controls. The multivariate-adjusted OR of colorectal cancer according to quintile categories of coffee polyphenols (from the first to top quintile) were 1.00 (referent), 0.81 (95%CI: 0.60-1.10), 0.65 (95%CI: 0.47-0.89), 0.65 (95%CI: 0.46-0.89) and 0.82 (95%CI: 0.60-1.10), respectively (P trend = 0.07). Similar, but less pronounced, decreases in the OR were also noted for the third and fourth quintiles of total polyphenol intake. Tea polyphenols and non-coffee polyphenols showed no association with colorectal cancer risk. The site-specific analysis, based on 463 colon cancer cases and 340 rectal cancer cases, showed an inverse association between coffee polyphenols and colon cancer. The multivariate-adjusted OR of colon cancer for the first to top quintiles of coffee polyphenols were 1.00 (referent), 0.92 (95%CI: 0.64-1.31), 0.75 (95%CI: 0.52-1.08), 0.69 (95%CI: 0.47-1.01), and 0.68 (95%CI: 0.46-1.00), respectively (P trend = 0.02). Distal colon cancer showed a more evident inverse association with coffee polyphenols than proximal colon cancer. The association between coffee polyphenols and rectal cancer risk was U-shaped, with significant decreases in the OR at the second to fourth quintile categories. There was also a tendency that the OR of colon and rectal cancer decreased in the intermediate categories of total polyphenols. The decrease in the OR in the intermediate categories of total polyphenols was most pronounced for distal colon cancer. Intake of tea polyphenols was not associated with either colon or rectal cancer. The associations of coffee consumption with colorectal, colon and rectal cancers were almost the same as observed for coffee polyphenols. The trend of the association between coffee consumption and colorectal cancer was statistically significant.
  
  
  CONCLUSIONS
  The present findings suggest a decreased risk of colorectal cancer associated with coffee consumption.
authors.affiliation: Department of Preventive Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. wangzj@phealth.med.kyushu-u.ac.jp
authors.forename: Zhen-Jie
authors.initials: ZJ
authors.lastname: Wang
authors.forename: Keizo
authors.initials: K
authors.lastname: Ohnaka
authors.forename: Makiko
authors.initials: M
authors.lastname: Morita
authors.forename: Kengo
authors.initials: K
authors.lastname: Toyomura
authors.forename: Suminori
authors.initials: S
authors.lastname: Kono
authors.forename: Takashi
authors.initials: T
authors.lastname: Ueki
authors.forename: Masao
authors.initials: M
authors.lastname: Tanaka
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kakeji
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Maehara
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okamura
authors.forename: Koji
authors.initials: K
authors.lastname: Ikejiri
authors.forename: Kitaroh
authors.initials: K
authors.lastname: Futami
authors.forename: Takafumi
authors.initials: T
authors.lastname: Maekawa
authors.forename: Yohichi
authors.initials: Y
authors.lastname: Yasunami
authors.forename: Kenji
authors.initials: K
authors.lastname: Takenaka
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ichimiya
authors.forename: Reiji
authors.initials: R
authors.lastname: Terasaka
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000517:prevention & control*; D000368:Aged; D016588:Anticarcinogenic Agents / Q000008:administration & dosage*; D003069:Coffee; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D004032:Diet; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D059808:Polyphenols / Q000008:administration & dosage*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013662:Tea; D013997:Time Factors
chemical_list: D016588:Anticarcinogenic Agents; D003069:Coffee; D059808:Polyphenols; D013662:Tea
keywords: Coffee; Colon cancer; Colorectal cancer; Polyphenols; Rectal cancer; Tea