Association between Dietary Zinc and Selenium Intake, Oxidative Stress-Related Gene Polymorphism, and Colorectal Cancer Risk in Chinese Population - A Case-Control Study.

Zinc and selenium may protect against colorectal cancer (CRC) progression through their anti-oxidative effects. This study examined the independent and combined effect of dietary zinc and selenium intake, and polymorphisms of the oxidative stress-related genes (superoxide dismutase 1, superoxide dismutase 2, glutathione peroxidase, and catalase) on CRC risk in a Chinese case-control study. A total of 493 cases and 498 sex and age-matched controls were randomly selected from an ongoing case-control study. Dietary information was assessed through face-to-face interviews using a validated food frequency questionnaire. Multiplex PCR-ligase detection reaction was used for genotyping the target SNPs. Multivariable logistic regression was used to estimate the odds ratios (ORs) and 95% confidence interval (CI). Intake of selenium was found to be inversely associated with CRC risk, while zinc was not associated with CRC risk. The ORs (95% CI) for the highest the lowest quartile were 0.42 (95% CI 0.28, 0.64, < 0.001) for selenium and 0.96 (95% CI 0.63, 1.47, = 0.505) for zinc. Combined effect was observed between zinc and rs4998557 on CRC risk ( < 0.05). This study identified a novel diet-gene interaction in the oxidative stress pathway on CRC risk in Chinese population.