Food groups and the risk of colorectal cancer: results from a Jordanian case-control study

The role of diet in colorectal cancer (CRC) in Jordan has not been studied previously. This study aimed at examining the association between food groups (including grains, fruits, vegetables, milk, and meat and legumes) and CRC risk in Jordan. We compared intakes of the different food groups among CRC patients (n=167) and matched controls (n=240) by age, sex, occupation, and marital status. A validated food frequency questionnaire was used to collect dietary data. Logistic regression was used to evaluate the association of quartiles of intakes of the different food groups with CRC risk. In addition, the association of selected food items with CRC risk was examined. Odds ratios (ORs) for the fourth versus the first quartile of intake were 2.92 [95% confidence interval (CI): 1.40-6.08] for grains, 1.66 (95% CI: 0.81-3.40) for vegetables, 0.55 (95% CI: 0.26-1.16) for fruits, 0.96 (95% CI: 0.46-1.97) for milk, and 1.43 (95% CI: 0.68-2.98) for meat and legumes. In a comparison of the highest with the lowest weekly frequency of consumption, there was a direct association between the risk of CRC and the frequency of consumption of chicken (OR=2.52, 95% CI: 1.33-4.77). An increase in risk was observed with increased consumption of white bread (OR=3.13, 95% CI: 1.18-9.25), whereas consumption of whole bread was associated with a decreased risk for CRC (OR=0.32, 95% CI: 0.12-0.84). Our results support a role of diet in CRC. Direct associations were found for grains, white bread, and chicken, whereas an inverse relation was reported for whole bread.