Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, United Kingdom.
PLoS One. 2012;7(6):e39361. doi: 10.1371/journal.pone.0039361. Epub 2012 Jun 22.
Earlier analyses within the EPIC study showed that dietary fibre intake was inversely associated with colorectal cancer risk, but results from some large cohort studies do not support this finding. We explored whether the association remained after longer follow-up with a near threefold increase in colorectal cancer cases, and if the association varied by gender and tumour location.
METHODOLOGY/PRINCIPAL FINDINGS: After a mean follow-up of 11.0 years, 4,517 incident cases of colorectal cancer were documented. Total, cereal, fruit, and vegetable fibre intakes were estimated from dietary questionnaires at baseline. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models stratified by age, sex, and centre, and adjusted for total energy intake, body mass index, physical activity, smoking, education, menopausal status, hormone replacement therapy, oral contraceptive use, and intakes of alcohol, folate, red and processed meats, and calcium. After multivariable adjustments, total dietary fibre was inversely associated with colorectal cancer (HR per 10 g/day increase in fibre 0.87, 95% CI: 0.79-0.96). Similar linear associations were observed for colon and rectal cancers. The association between total dietary fibre and risk of colorectal cancer risk did not differ by age, sex, or anthropometric, lifestyle, and dietary variables. Fibre from cereals and fibre from fruit and vegetables were similarly associated with colon cancer; but for rectal cancer, the inverse association was only evident for fibre from cereals.
CONCLUSIONS/SIGNIFICANCE: Our results strengthen the evidence for the role of high dietary fibre intake in colorectal cancer prevention.
EPIC 研究中的早期分析表明，膳食纤维的摄入量与结直肠癌的风险呈负相关，但一些大型队列研究的结果并不支持这一发现。我们通过近三倍的结直肠癌病例随访时间，探讨了这种关联在更长时间的随访后是否仍然存在，以及这种关联是否因性别和肿瘤位置而异。
方法/主要发现：平均随访 11.0 年后，记录了 4517 例结直肠癌的发病病例。基线时，通过饮食问卷估计总膳食纤维、谷物纤维、水果纤维和蔬菜纤维的摄入量。使用 Cox 比例风险模型分层分析年龄、性别和中心，调整总能量摄入、体重指数、体力活动、吸烟、教育、绝经状态、激素替代疗法、口服避孕药使用以及酒精、叶酸、红肉和加工肉类以及钙的摄入量，估计风险比（HR）和 95%置信区间（CI）。在多变量调整后，总膳食纤维与结直肠癌呈负相关（纤维每增加 10 克/天，HR 为 0.87，95%CI：0.79-0.96）。对于结肠癌和直肠癌，也观察到类似的线性关联。总膳食纤维与结直肠癌风险之间的关联与年龄、性别或人体测量、生活方式和饮食变量无关。来自谷物的膳食纤维和来自水果和蔬菜的膳食纤维与结肠癌呈相似的相关性；但对于直肠癌，仅来自谷物的膳食纤维呈负相关。
结论/意义：我们的结果加强了高膳食纤维摄入在结直肠癌预防中的作用的证据。
