Association between adherence to a dietary approach to stop hypertension and the Mediterranean diets and risk of colorectal cancer: A matched case-control study.

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers and is currently the third leading cause of cancer-related deaths worldwide. This study aimed to evaluate whether the dietary approach to stop hypertension (DASH) and Mediterranean (MED) diets are associated with CRC in Iranian adults. METHODS: This hospital-based case-control study was conducted on 71 cases and 142 controls (40-75 years old) in three general hospitals in Tehran, Iran. The dietary intakes of individuals were collected through face-to-face interviews using a semi-quantitative food frequency questionnaire (FFQ) that included 125 food items. The DASH and MED diet scores were calculated according to food items based on guidelines. Two logistic regression models were applied to evaluate the association between DASH and MED score adherence. RESULTS: After adjusting for confounding factors, a negative association between DASH diet adherence and CRC risk was observed in the second and last tertile compared to the first tertile (T) (T2: odds ratio (OR) = 0.33; 95% confidence interval (CI): 0.14-0.77 - T3: OR = 0.09; 95% CI: 0.03-0.27). There was no significant association between the MED diet and the risk of CRC. CONCLUSIONS: In conclusion, the current study's findings presented that adherence to a DASH diet could reduce the odds of CRC.

The association between pro-vegetarian dietary pattern and risk of colorectal cancer: a matched case-control study.

BACKGROUND: Few studies assess the link between plant-based diets and colorectal cancer (CRC) incidence. To our knowledge, no study has examined the association between pro-vegetarian dietary pattern (PDP) and CRC globally or among Iranians. Therefore, the objective of our matched case-control study was to evaluate the association between PDP and CRC in the Iranian population. METHODS: The present research was a hospital-based case (n = 71)-control (n = 142) study conducted in the same hospitals in Tehran, Iran. This study used a reliable and valid semi-quantitative food frequency questionnaire to evaluate the participants' dietary intake. According to the residual method, the selected plant and animal foods have been adjusted in the total energy intake to calculate the PDP index. Odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for confounding variables were also expressed using logistic regression by SPSS software. RESULTS: In the crude and adjusted models, we observed that the odds of CRC decreased significantly in the 3rd and last quartile of PDP compared to the 1st quartile (Q) (Crude model: Q3: OR = 0.36, 95% CI: 0.17 - 0.79, P-value = 0.011 and Q4: OR = 0.33, 95% CI: 0.14 - 0.79, P-value = 0.012 - Adjusted model: Q3: OR = 0.41, 95% CI: 0.18 - 0.94, P-value = 0.035 and Q4: OR = 0.35, 95% CI: 0.14 - 0.87, P-value = 0.025). CONCLUSIONS: Based on the results of the present case-control study in the Iranian population, it was concluded that PDP, which involves consuming vegetables, fruits, cereals, dairy products, and low meat consumption, reduces the odds of CRC. In conclusion, adherence to PDP is associated with a decreased odds of CRC.

Oxidative balance score and dietary phytochemical index can reduce the risk of colorectal cancer in Iranian population.

BACKGROUND: No previous study has assessed the association between oxidative balance score (OBS) and dietary phytochemical index (DPI) with colorectal cancer (CRC) simultaneously. Therefore, this study investigated the association between OBS and DPI with the odds of CRC among the Iranian population. METHODS: This hospital-based age and sex-matched case-control study was conducted between September 2008 and January 2010 (142 controls and 71 cases were entered for analysis). New diagnosed CRC cases were selected from the Cancer Institute, Imam Khomeini Hospital of Tehran. Dietary intakes were determined by a semi-quantitative food frequency questionnaire (FFQ). Then, dietary indices were calculated by food items and nutrient intake. Logistic regression was utilized for assessing the tertiles of OBS and DPI. RESULTS: In multivariate analysis, OBS was associated with a 77% reduction in CRC odds in the last tertile than the first tertile (odds ratio (OR) = 0.23, confidence interval (CI): 0.07-0.72, Ptrend = 0.017). Also, we found a 64% reduction in CRC odds in the last tertile of DPI compared to the first tertile (OR = 0.36, CI: 0.15-0.86, Ptrend = 0.015). CONCLUSIONS: A diet rich in phytochemicals and anti-oxidants, including fruits and vegetables (citrus fruits, colored berries, and dark-green leafy vegetables) and whole grains, may reduce the CRC odds.

Ultra-Processed Food Intake and Risk of Colorectal Cancer: A Matched Case-Control Study.

Colorectal cancer (CRC) is the third most prevalent and the second fatal cancer in the world. Ultra-processed foods (UPFs) are suggested to be related to various non-communicable diseases including cancers. However, studies on the relationship between UPFs and CRC are scarce. The aim of this study was to determine the association between consumption of UPFs and CRC. In a case-control study conducted in four hospitals in Tehran, Iran, consumption of UPFs in 71 CRC patients and 142 controls (patients with non-neoplastic diseases) were compared. Using 125-item semi-quantitative food frequency questionnaire, dietary intakes were assessed. We used Multivariate logistic regression to estimate the association between UPFs intake and risk of CRC. Intake of nondairy beverages (P = 0.009), processed meat and fast food (P = 0.04) was significantly higher in those in the highest tertile of UPFs intake compared to the lowest tertile. In addition, intake of UPFs was associated with higher risk of CRC. The association remained constant after adjustment for BMI, income, smoking, type of job, educational level, and physical activity (OR, 3.32; 95% CI, 1.44-7.61; P = 0.003). Results of this study indicate that the intake of UPFs is associated with increased odds of CRC.