Brief Article
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World J Gastroenterol. May 7, 2013; 19(17): 2683-2690
Published online May 7, 2013. doi: 10.3748/wjg.v19.i17.2683
Dietary polyphenols and colorectal cancer risk: The Fukuoka colorectal cancer study
Zhen-Jie Wang, Keizo Ohnaka, Makiko Morita, Kengo Toyomura, Suminori Kono, Takashi Ueki, Masao Tanaka, Yoshihiro Kakeji, Yoshihiko Maehara, Takeshi Okamura, Koji Ikejiri, Kitaroh Futami, Takafumi Maekawa, Yohichi Yasunami, Kenji Takenaka, Hitoshi Ichimiya, Reiji Terasaka
Zhen-Jie Wang, Makiko Morita, Kengo Toyomura, Suminori Kono, Department of Preventive Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
Keizo Ohnaka, Department of Geriatric Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
Takashi Ueki, Masao Tanaka, Departments of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
Yoshihiro Kakeji, Yoshihiko Maehara, Departments of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
Takeshi Okamura, Department of Gastroenterological Surgery, National Kyushu Cancer Center, 3-1-1 Notame, Minami-ku, Fukuoka 811-1395, Japan
Koji Ikejiri, Division of Surgery, National Kyushu Medical Center, 1-8-1 Jigyohama, Chuo-ku, Fukuoka 810-8563, Japan
Kitaroh Futami, Takafumi Maekawa, Department of Surgery, Fukuoka University Chikushi Hospital, 377-1 Oaza-zokumyoin, Chikushino-shi 818-0067, Japan
Yohichi Yasunami, Department of Regenerative Medicine and Transplantation, Faculty of Medicine, Fukuoka University, 4-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
Kenji Takenaka, Division of Surgery, Fukuoka City Hospital, 13-1 Yoshizuka-honmachi, Hakata-ku, Fukuoka 812-0046, Japan
Hitoshi Ichimiya, Division of Surgery, Hamanomachi General Hospital, 3-5-27 Maizuru, Chuo-ku, Fukuoka 810-8539, Japan
Reiji Terasaka, Division of Surgery, Fukuoka Red Cross Hospital, 3-1-1 Ogusu, Minami-ku, Fukuoka 815-8555, Japan
Author contributions: Wang ZJ developed the concept of the study, performed data analysis and prepared the draft; Kono S was in charge of the whole process including preparation of the manuscript; Ohnaka K, Morita M, and Toyomura K supported the data analysis and preparation of the draft; Ueki T, Tanaka M, Kakeji Y, Maehara Y, Okamura T, Ikejiri K, Futami K, Maekawa T, Yasunami Y, Takenaka K, Ichimiya H, and Terasaka R were in charge of implementation of the survey of the cases. All authors contributed to interpretation of the results and to critical revision of the manuscript for intellectual content.
Supported by The Scientific Support Programs for Cancer Research, Grant-in-Aid for Scientific Research on Innovative Areas, the Ministry of Education, Culture, Sports, Science and Technology, Japan
Correspondence to: Zhen-Jie Wang, MD, 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
Telephone: +81-92-6426110 Fax: +81-92-6426115
Received: August 28, 2012
Revised: November 7, 2012
Accepted: December 27, 2012
Published online: May 7, 2013
Abstract

AIM: 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 (Ptrend = 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 (Ptrend = 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.

CONCLUSION: The present findings suggest a decreased risk of colorectal cancer associated with coffee consumption.

Keywords: Colorectal cancer, Colon cancer, Rectal cancer, Polyphenols, Coffee, Tea