Zhao Jing, Zhu Yun, Du Meizhi, Wang Yu, Vallis Jillian, Parfrey Patrick S, Mclaughlin John R, Qi Xiuying, Wang Peizhong Peter
Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin 300070, China.
Division of Community Health and Humanities, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL A1B 3V6, Canada.
Cancers (Basel). 2022 Aug 4;14(15):3801. doi: 10.3390/cancers14153801.
We examined dietary fiber intake for its relevance to Colorectal cancer (CRC) survival in a cohort of CRC patients and a meta-analysis including results from four prospective cohort studies. We analyzed 504 CRC patients enrolled in the Newfoundland Familial Colorectal Cancer Study (NFCCS) who were newly diagnosed with CRC between 1999 and 2003. Follow-up for deaths was through April 2010. All participants completed a self-administered food frequency questionnaire to evaluate their dietary intakes one year before diagnosis. Multivariable Cox proportional hazard models were used to explore the associations of dietary fiber intake with all-cause mortality and CRC-specific mortality. In the meta-analysis, we identified prospective cohort studies published between January 1991 and December 2021 by searching PubMed, EMBASE, and Cochrane Library. Fixed-effects or random-effects models were used to combine the study-specific hazard ratio (HR) from our original analysis and three other cohorts. In the NFCCS, we found that CRC patients with the second quartile of dietary fiber intake had a 42% lower risk of all-cause mortality (HR: 0.58, 95% CI: 0.35-0.98) and 58% lower risk of CRC-specific mortality (HR: 0.42, 95% CI: 0.21-0.87) compared with those with the lowest quartile. In the meta-analysis, a similar inverse association between dietary fiber and total mortality was detected among CRC patients; each 10 g/day increase in dietary fiber intake was associated with a 16% decreased risk of total mortality. The dose-response meta-analysis showed a linear relationship between dietary fiber intake and all-cause mortality, with no sign of a plateau. For CRC-specific mortality, intriguingly, the benefit associated with increasing dietary fiber intake achieved its maximum at approximately 22 g/day, and no further reduction in CRC-specific mortality was observed beyond this intake level. Our results suggest that high dietary fiber intake may be associated with prolonged survival among CRC patients. Our findings add to the sparse literature on the role of dietary fiber in CRC survival.
我们在一组结直肠癌（CRC）患者中研究了膳食纤维摄入量与结直肠癌生存的相关性，并进行了一项荟萃分析，纳入了四项前瞻性队列研究的结果。我们分析了504名参加纽芬兰家族性结直肠癌研究（NFCCS）的CRC患者，这些患者于1999年至2003年间新诊断为CRC。随访至2010年4月的死亡情况。所有参与者均完成了一份自行填写的食物频率问卷，以评估他们在诊断前一年的饮食摄入量。使用多变量Cox比例风险模型来探讨膳食纤维摄入量与全因死亡率和CRC特异性死亡率之间的关联。在荟萃分析中，我们通过检索PubMed、EMBASE和Cochrane图书馆，确定了1991年1月至2021年12月期间发表的前瞻性队列研究。使用固定效应或随机效应模型来合并我们原始分析和其他三个队列的研究特异性风险比（HR）。在NFCCS中，我们发现膳食纤维摄入量处于第二四分位数的CRC患者与最低四分位数的患者相比，全因死亡率风险降低42%（HR：0.58，95%CI：0.35-0.98），CRC特异性死亡率风险降低58%（HR：0.42，95%CI：0.21-0.87）。在荟萃分析中，CRC患者中膳食纤维与总死亡率之间也检测到类似的负相关；膳食纤维摄入量每增加10克/天，总死亡率风险降低16%。剂量反应荟萃分析显示膳食纤维摄入量与全因死亡率之间呈线性关系，没有达到平台期的迹象。有趣的是，对于CRC特异性死亡率，与增加膳食纤维摄入量相关的益处约在22克/天达到最大值，超过此摄入量水平未观察到CRC特异性死亡率进一步降低。我们的结果表明，高膳食纤维摄入量可能与CRC患者的生存期延长有关。我们的发现补充了关于膳食纤维在CRC生存中作用的稀少文献。
