Selected xenobiotics in foods: estimates in an Italian population

Introduction: Dietary exposure to potential carcinogens such as Heterocyclic Amines (HAs), Polycyclic Aromatic Hydrocarbons (PAHs), and N-nitroso compounds, represents a concern in nutritional epidemiology. As these compounds originate from common industrial processes, high-temperature cooking, and cultivation, quantifying population intake is of interest to inform evidence-based nutrition and food safety policies. Objectives: To evaluate the intakes and main food sources of: HAs, including 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP); PAHs, including benzo[a]pyrene (B[a]P), dibenzo[a]anthracene (DiB[a]A), and total PAHs; nitrites; nitrates; and nitrosamines, including N-nitrosodimethylamine (NDMA), N-nitrosopiperidine (NPIP), and N-nitrosopyrrolidine (NPYR) in an Italian population. Methods: We analyzed 100 healthy controls from a colorectal cancer case-control study (Milan, 2017–2019). Intake was assessed via an 81-item food frequency questionnaire. Content of xenobiotics was retrieved from EPIC Carcinogen Database, CHARRED-NIH, Italian food composition data (CREA), and additional published sources. Daily intakes considered weekly consumption frequencies and portion sizes. Results: Median daily intakes were 0.10ng for IQ, 48.95ng for MeIQx, 7.88ng for DiMeIQx, 270.95ng for PhIP, 0.08µg for B[a]P, 0.07µg for DiB[a]A, 2.20µg for total PAHs, 91.50mg for nitrates, 0.36mg for nitrites, 0.05µg for NDMA, 0.02µg for NPIP, and 0.03µg for NPYR. No material differences were found between sexes. Major food sources for HAs were vegetable side dishes (54%) and pasta/soups (32%) for IQ, beef (54%) and poultry (44%) for MeIQx, and poultry for DiMeIQx (78%) and PhIP (87%). For PAHs, fish was the main source of B[a]P (35%) and total PAHs (40%), followed by pizza (18% for total PAHs), while beer (49%) and fish (40%) contributed most to DiB[a]A. Regarding N-nitroso compounds, processed meats were the primary source for NPIP/NPYR (92%) and nitrites (44%); NDMA was derived from processed meats (34%) and pasta with ragù (27%), while spinach (51%) and leafy vegetables (15%) were the leading sources of nitrates. Conclusions: The main sources of xenobiotics are meats, processed meats, fish, pizza, and beer (depending on cooking methods and industrial processes) and leafy vegetables, influenced by cultivation methods. Further studies will be able to investigate how these compounds may impact cancer risk.