Koushik Anita, Hunter David J, Spiegelman Donna, Beeson W Lawrence, van den Brandt Piet A, Buring Julie E, Calle Eugenia E, Cho Eunyoung, Fraser Gary E, Freudenheim Jo L, Fuchs Charles S, Giovannucci Edward L, Goldbohm R Alexandra, Harnack Lisa, Jacobs David R, Kato Ikuko, Krogh Vittorio, Larsson Susanna C, Leitzmann Michael F, Marshall James R, McCullough Marjorie L, Miller Anthony B, Pietinen Pirjo, Rohan Thomas E, Schatzkin Arthur, Sieri Sabina, Virtanen Mikko J, Wolk Alicja, Zeleniuch-Jacquotte Anne, Zhang Shumin M, Smith-Warner Stephanie A
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.
J Natl Cancer Inst. 2007 Oct 3;99(19):1471-83. doi: 10.1093/jnci/djm155. Epub 2007 Sep 25.
Fruit and vegetable intakes have been associated with a reduced risk of colon cancer; however, in more recent studies associations have been less consistent. Statistical power to examine associations by colon site has been limited in previous studies.
Fruit and vegetable intakes in relation to colon cancer risk were examined in the Pooling Project of Prospective Studies of Diet and Cancer. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated separately in 14 studies using Cox proportional hazards model and then pooled using a random-effects model. Intakes of total fruits and vegetables, total fruits, and total vegetables were categorized according to quintiles and absolute cutpoints. Analyses were conducted for colon cancer overall and for proximal and distal colon cancer separately. All statistical tests were two-sided.
Among 756,217 men and women followed for up to 6 to 20 years, depending on the study, 5838 were diagnosed with colon cancer. The pooled multivariable RRs (95% CIs) of colon cancer for the highest versus lowest quintiles of intake were 0.91 (0.82 to 1.01, P(trend) = .19) for total fruits and vegetables, 0.93 (0.85 to 1.02, P(trend) = .28) for total fruits, and 0.94 (0.86 to 1.02, P(trend) = .17) for total vegetables. Similar results were observed when intakes were categorized by identical absolute cut points across studies (pooled multivariable RR = 0.90, 95% CI = 0.77 to 1.05 for 800 or more versus <200 g/day of total fruits and vegetables, P(trend) = .06). The age-standardized incidence rates of colon cancer for these two intake categories were 54 and 61 per 100,000 person-years, respectively. When analyzed by colon site, the pooled multivariable RRs (95% CIs) comparing total fruit and vegetable intakes of 800 or more versus less than 200 g/day were 0.74 (0.57 to 0.95, P(trend) = .02) for distal colon cancers and 1.02 (0.82 to 1.27, P(trend) = .57) for proximal colon cancers. Similar site-specific associations were observed for total fruits and total vegetables.
Fruit and vegetable intakes were not strongly associated with colon cancer risk overall but may be associated with a lower risk of distal colon cancer.
水果和蔬菜的摄入量与结肠癌风险降低相关；然而，在最近的研究中，这种关联并不那么一致。以往研究中，按结肠部位检验关联的统计效能有限。
在饮食与癌症前瞻性研究汇总项目中，研究了水果和蔬菜摄入量与结肠癌风险的关系。使用Cox比例风险模型在14项研究中分别估计相对风险（RRs）和95%置信区间（CIs），然后使用随机效应模型进行汇总。根据五分位数和绝对切点对总水果和蔬菜、总水果以及总蔬菜的摄入量进行分类。对总体结肠癌以及近端和远端结肠癌分别进行分析。所有统计检验均为双侧检验。
在根据研究随访长达6至20年的756,217名男性和女性中，5838人被诊断患有结肠癌。总水果和蔬菜摄入量最高与最低五分位数相比，结肠癌的汇总多变量RRs（95% CIs）为0.91（0.82至1.01，P趋势=0.19）；总水果为0.93（0.85至1.02，P趋势=0.28）；总蔬菜为0.94（0.86至1.02，P趋势=0.17）。当根据各研究相同的绝对切点对摄入量进行分类时，观察到类似结果（总水果和蔬菜摄入量≥800克/天与<200克/天相比，汇总多变量RR = 0.90，95% CI = 0.77至1.05，P趋势=0.06）。这两种摄入量类别中结肠癌的年龄标准化发病率分别为每10万人年54例和61例。按结肠部位分析时，总水果和蔬菜摄入量≥800克/天与<200克/天相比，远端结肠癌的汇总多变量RRs（95% CIs）为0.74（0.57至0.95，P趋势=0.02），近端结肠癌为1.02（0.82至1.27，P趋势=0.57）。总水果和总蔬菜也观察到类似的部位特异性关联。
总体而言，水果和蔬菜摄入量与结肠癌风险无强关联，但可能与远端结肠癌风险较低相关。
