Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology, Research Institute, Shahid Beheshti University of Medical Sciences, Tehran 11369, Iran.
Student Research Committee, Department and Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran 11369, Iran.
Nutrients. 2019 May 28;11(6):1213. doi: 10.3390/nu11061213.
Chronic inflammation is implicated in the development of colorectal cancer (CRC) and its precursor; colorectal adenomatous polyps (CAP). Some dietary factors are important triggers for systemic inflammation. Therefore, the present study aimed to investigate the association between the dietary inflammatory index (DII) and the risk of CRC and CAP in an Iranian case-control study.
134 newly diagnosed CRC patients, 130 newly diagnosed CAP patients, and 240 hospitalized controls were recruited using convenience sampling. Energy-adjusted DII (E-DII) scores were computed based on dietary intake assessed using a reproducible and valid 148-item food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CI) after adjusting for confounders.
The E-DII score ranged between -4.23 (the most anti-inflammatory score) to +3.89 (the most pro-inflammatory score). The multivariable-adjusted ORs for participants in the 3 tertile compared to the 1 tertile was 5.08 (95%CI: 2.70-9.56; P-trend < 0.0001) for CRC and 2.33 (95% CI: 1.30-4.02; P-trend = 0.005) for CAP.
Our findings suggest that more pro-inflammatory diets, indicated by higher E-DII scores, might increase the risk of both CRC and CAP. Future steps should include testing these associations in a prospective setting in Iran.
慢性炎症与结直肠癌（CRC）及其前体；结直肠腺瘤性息肉（CAP）的发展有关。一些饮食因素是全身炎症的重要触发因素。因此，本研究旨在通过伊朗病例对照研究调查饮食炎症指数（DII）与 CRC 和 CAP 风险之间的关系。
采用便利抽样法招募了 134 例新诊断的 CRC 患者、130 例新诊断的 CAP 患者和 240 例住院对照。根据使用可重复和有效的 148 项食物频率问卷评估的饮食摄入量，计算出能量调整后的 DII（E-DII）评分。调整混杂因素后，使用逻辑回归模型估计比值比（OR）和 95%置信区间（CI）。
E-DII 评分范围在-4.23（最抗炎评分）至+3.89（最促炎评分）之间。与 1 tertile 相比，3 tertile 组的多变量调整 OR 为 CRC 5.08（95%CI：2.70-9.56；P-trend < 0.0001），CAP 2.33（95% CI：1.30-4.02；P-trend = 0.005）。
我们的研究结果表明，更促炎的饮食，表现为更高的 E-DII 评分，可能会增加 CRC 和 CAP 的风险。未来的步骤应包括在伊朗的前瞻性研究中检验这些关联。
