THE RELATIONSHIP BETWEEN THE INDEX OF NUTRITIONAL QUALITY (INQ) AND COLORECTAL CANCER AND ADENOMA RISK: A CASE-CONTROL STUDY

Background and Aim: Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the word. Dietary factors have shown that associated with the risk of colorectal cancer and adenoma. The index of nutritional quality (INQ) is an attempt to provide a general overview of the nutrient content of diet. The aim of this study is to determine the relationship between INQ and the risk of Colorectal Cancer and adenomas. Methods: Overall, 129 colorectal cancer and 130 colorectal adenoma cases and 240 healthy controls were studied in three major general hospitals in Tehran province, Iran. INQ scores were calculated based on information on the usual diet that was assessed by a valid and reliable Food Frequency Questionnaire (FFQ) consisting of 147 food items. Multivariate logistic regression was used to estimate the relationship between INQ scores and risk of colorectal cancer and adenoma.Results: After controlling for several confounding factors, the INQ of calcium, vitamin C, riboflavin, folate and fiber were associated with decreased risk of CRC (ORcalcium: 0.15 (0.05-0.41), ORvtiC: 0.16 (0.09-0.28), ORvitB2: 0.31 (0.16-0.58), ORfolate: 0.30 (0.15-0.62), ORfiber: 0.34 (0.21-0.57)). However, the inverse association were observed between risk of CRA and the INQ of vitamin C, riboflavin, folate and fiber (ORvtiC: 0.49 (0.33-0.72), ORvitB2: 0.51 (0.29-0.89), ORfolate: 0.51 (0.27-0.95), ORfiber: 0.64 (0.43-0.95)).Conclusion: This study showed that individuals who have a healthier and nutrient-rich diet such as calcium, vitamin C, riboflavin, folate and fiber at a lower risk of CRC and CRA than those with unhealthy and poor diet.