■饮食成分可以影响结直肠癌(CRC)的发病率。叶酸是在DNA结构形成中起重要作用的化合物之一,可以导致或预防肿瘤发生。本研究是队列研究的第一个系统评价和剂量反应荟萃分析,评估膳食叶酸摄入量与CRC风险之间的关系。
■PubMed/Medline,Scopus,和ISIWebofScience数据库在2024年1月之前系统搜索了评估叶酸摄入量与CRC相关性的队列研究.使用随机效应模型计算汇总相对风险(RR)和95%置信区间(CI)。此外,我们对叶酸摄入量与CRC风险之间的剂量-反应相关性进行了线性和非线性剂量-反应分析.
■18项前瞻性队列研究,931,469名参与者,14,860例CRC患者,3536例结肠癌(CC)患者,1075例直肠癌(RC)患者被纳入分析。饮食叶酸摄入量每增加100μg,CRC的总RR为0.97(95%CI:0.95-0.99,I2:0.0%,P-异质性:0.616),这可能与BMI相关(0.97(95%CI:0.95-0.99));在饮酒(0.97(95%CI:0.95-0.99))和吸烟(0.97(95%CI:0.95-0.99))的受试者中也观察到了更多的保护作用。此外,与CC风险降低7%呈正相关(0.93(95%CI:0.87-0.99,I2:33.7%,P-异质性:0.159)),RC的零关系为0.98(95%CI:0.90-1.08),I2:16.6%,P-异质性:0.309)。有非线性的证据表明,每天摄入高达500μg的叶酸与CC成反比(P非线性=0.04)。
■研究结果表明,膳食叶酸摄入量与CRC风险呈负相关,尤其是高危人群,那些BMI较高的人,酗酒者,和吸烟者。
UNASSIGNED: Dietary components can influence the incidence of colorectal cancer (CRC). Folate is one of the compounds that plays an essential role in the formation of DNA structures, which can lead to or prevent tumorigenesis. The present study is the first systematic review and dose-response meta-analysis of cohort studies evaluating the association between dietary folate intake and the risk of CRC.
UNASSIGNED: The PubMed/Medline, Scopus, and ISI Web of Science databases were systematically searched for cohort studies that assessed the association between folate intake and CRC up to January 2024. Summary relative risks (RRs) and 95 % confidence intervals (CIs) were calculated using a random effects model. Also, linear and nonlinear dose-response analyses were conducted for the dose-response associations between folate intake and risk of CRC.
UNASSIGNED: Eighteen prospective cohort studies with 931,469 participants, 14,860 CRC patients, 3536 colon cancer (CC) patients, and 1075 rectal cancer (RC) patients were included in the analysis. The summary RR of CRC for each 100-μg increase in dietary folate intake was 0.97 (95 % CI: 0.95-0.99, I2: 0.0 %, P-heterogeneity: 0.616), which can be related to BMI (0.97 (95 % CI: 0.95-0.99)); a more protective effect was also observed in subjects who drank alcohol (0.97 (95 % CI: 0.95-0.99)) and those who smoked (0.97 (95 % CI: 0.95-0.99)). Additionally, it was positively related to a 7 % lower risk of CC (0.93 (95 % CI: 0.87-0.99, I2: 33.7 %, P-heterogeneity: 0.159)), and the null relation for RC was 0.98 (95 % CI: 0.90-1.08), I2: 16.6 %, P-heterogeneity: 0.309). There was evidence of nonlinearity in which up to 500 μg/day dietary folate intake was inversely associated with CC (P nonlinearity = 0.04).
UNASSIGNED: The findings showed an inverse association between dietary folate intake and the risk of CRC, especially in high-risk persons, those who have a higher BMI, alcohol drinkers, and smokers.