The D1822V APCpolymorphism interacts with fat, calcium, and fiber intakes in modulating the risk of colorectal cancer in Portuguese persons

Abstract

Background:Both genetic and environmental factors affect the risk of colorectal cancer (CRC).Objective:We aimed to examine the interaction between the D1822Vpolymorphism of the APCgene and dietary intake in persons with CRC.Design:Persons with CRC (n= 196) and 200 healthy volunteers, matched for age and sex in a case-control study, were evaluated with respect to nutritional status and lifestyle factors and for the D1822Vpolymorphism.Results:No significant differences were observed in energy and macronutrient intakes. Cases had significantly (P< 0.05) lower intakes of carotenes, vitamins C and E, folate, and calcium than did controls. Fiber intake was significantly (P= 0.004) lower in cases than in controls, whereas alcohol consumption was associated with a 2-fold risk of CRC. In addition, cases were significantly (P= 0.001) more likely than were controls to be sedentary. The homozygous variant for the APCgene (VV) was found in 4.6% of cases and in 3.5% of controls. Examination of the potential interactions between diet and genotype found that a high cholesterol intake was associated with a greater risk of colorectal cancer only in noncarriers (DD) of the D1822VAPCallele (odds ratio: 1.66; 95% CI: 1.00, 2.76). In contrast, high fiber and calcium intakes were more markedly associated with a lower risk of CRC in patients carrying the polymorphic allele (DV/VV) (odds ratio: 0.50; 95% CI: 0.27, 0.94 for fiber; odds ratio: 0.51; 95% CI: 0.28, 0.93 for calcium) than in those without that allele.Conclusion:These results suggest a significant interaction between the D1822Vpolymorphism and the dietary intakes of cholesterol, calcium, and fiber for CRC risk.