Department of Preventive Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
World J Gastroenterol. 2013 May 7;19(17):2683-90. doi: 10.3748/wjg.v19.i17.2683.
To investigate the associations between dietary intake of polyphenols and colorectal cancer.
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.
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.
The present findings suggest a decreased risk of colorectal cancer associated with coffee consumption.
研究多酚类物质的饮食摄入与结直肠癌的关系。
本研究对象来自福冈结直肠癌研究，这是一项基于社区的病例对照研究。研究对象为 816 例结直肠癌患者和 815 例社区对照者。通过计算机辅助访谈评估了 148 种食物的摄入量。我们使用 97 种食物来估计总多酚、茶和咖啡多酚的摄入量。Phenol-Explorer 数据库用于 92 种食物。对于不在 Phenol-Explorer 数据库中的 5 种食物，其中 3 种食物（红薯、さといも和大根）的多酚含量基于日本的一项研究，另外 2 种食物（大豆和炸薯条）的多酚含量则根据美国农业部数据库中的 ORAC 值进行估算。使用 logistic 回归模型，在调整年龄、性别、居住区域、结直肠癌家族史、吸烟、饮酒、10 年前的体重指数、职业类型、休闲时间体力活动以及钙和 n-3 多不饱和脂肪酸的摄入量后，获得结直肠癌风险的比值比（OR）和 95%置信区间（CI）。
病例组和对照组之间的总多酚或茶多酚摄入量没有明显差异，但咖啡多酚的摄入量在病例组中低于对照组。根据咖啡多酚（从第一到最高五分位数）的五分位数类别，结直肠癌的多变量调整 OR 分别为 1.00（参照）、0.81（95%CI：0.60-1.10）、0.65（95%CI：0.47-0.89）、0.65（95%CI：0.46-0.89）和 0.82（95%CI：0.60-1.10）（P 趋势=0.07）。总多酚摄入量的第三和第四五分位数也呈现出类似但程度较轻的 OR 降低。茶多酚和非咖啡多酚与结直肠癌风险没有关联。基于 463 例结肠癌病例和 340 例直肠癌病例的部位特异性分析显示，咖啡多酚与结肠癌呈负相关。咖啡多酚的第一到最高五分位数的结肠癌的多变量调整 OR 分别为 1.00（参照）、0.92（95%CI：0.64-1.31）、0.75（95%CI：0.52-1.08）、0.69（95%CI：0.47-1.01）和 0.68（95%CI：0.46-1.00）（P 趋势=0.02）。远端结肠癌与咖啡多酚的负相关关系比近端结肠癌更为明显。咖啡多酚与直肠癌风险呈 U 形关联，OR 在第二到第四五分位数类别中显著降低。总多酚摄入量的中间类别中也存在结直肠癌 OR 降低的趋势。总多酚摄入量的中间类别中，远端结肠癌的 OR 降低最为明显。茶多酚的摄入与结肠癌或直肠癌均无关联。咖啡消费与结直肠癌、结肠癌和直肠癌的关联几乎与咖啡多酚相同。咖啡消费与结直肠癌之间关联的趋势具有统计学意义。
本研究结果表明，咖啡摄入与结直肠癌风险降低有关。
