Effects of phenotypes in heterocyclic aromatic amine (HCA) metabolism–related genes on the association of HCA intake with the risk of colorectal adenomas
Objective: We studied the association between meat consumption and colorectal adenomas, and potential influence of genetic susceptibility to heterocyclic aromatic amines (HCAs) formed during meat cooking at high temperatures. Methods: We studied HCA concentration in relation to preparation habits among 63 volunteers. Associations of meat consumption, meat preparation habits, and genetic susceptibility with colorectal adenoma risk were investigated among 431 adenoma cases and 433 polyp-free controls recruited at endoscopy. Participants completed a meat consumption and preparation questionnaire and provided blood for DNA isolation. Polymorphisms of N-acetyltransferases (NAT) 1 and 2, sulfotransferase (SULT) 1A1, and glutathione-S-transferases (GST) M1 and T1 were determined. Results: HCAs were present in habitually prepared meat, although meat consumption (7 versus5x/week) did not increase the risk of colorectal adenomas (odds ratio (OR) 1.2, 95% confidence interval (CI) 0.8–1.9). Also, presumed unfavorable preparation habits (e.g., use of lid, preference for darkly browned meat) did not increase adenoma risk (OR 0.8 and 0.9, respectively). Only the combination of NAT2 slow acetylation and frequent meat consumption (>5x/week) slightly increased adenoma risk (OR 1.6, 95% CI 1.1–2.3). Conclusions: In this Dutch population, unfavorable meat consumption and preparation habits did not increase colorectal adenoma risk, and these associations were not influenced by relevant genetic polymorphisms.