High Dietary Iron and Copper and Risk of Colorectal Cancer: A Case-Control Study in Burgundy, France

Several hypotheses have been proposed for colorectal carcinogenesis, including formation of free radi- cals. A case-control study compared nutrient intake in 171 colorectal cancer cases versus 309 general population con- trols, using a detailed face-to-face food history question- naire. A food composition table enabled us to determine the mean composition of the diet in macro- and micronutrients. Dietary intakes were separately categorized into quartiles by gender. Logistic regression models were adjusted for age, sex, energy, exercise, and body mass index. High energy, cop- per, iron, and vitamin E intakes were associated with an over- all increased risk of colorectal cancer. The odds ratios asso- ciated with the fourth quartile of intake were 2.3 (95% confidence interval, 1.3-4.0), 2.4 (1.3-4.6), 2.2 (1.1-4.7), and 1.8 (1.0-3.4) for energy, copper, iron, and vitamin E, re- spectively. There were no significant associations with di- etary fiber, folate, calcium, or antioxidant vitamins other than vitamin E. These findings regarding iron and copper suggest that free radicals play an important role in colorectal carcinogenesis, while the findings regarding vitamin E are so far unexplained.