Effect of processed and red meat on endogenous nitrosation and DNA damage

• Published in: Carcinogenesis (New York) 2009-08, Vol.30 (8), p.1402-1407
• Main Authors: Joosen, Annemiek M.C.P., Kuhnle, Gunter G.C., Aspinall, Sue M., Barrow, Timothy M., Lecommandeur, Emmanuelle, Azqueta, Amaya, Collins, Andrew R., Bingham, Sheila A.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; Cancer Prevention; Carcinogenesis, carcinogens and anticarcinogens; Comet Assay; Cross-Over Studies; Diet, Vegetarian; DNA Damage; Feces - chemistry; Female; Heme - metabolism; Humans; Male; Meat - adverse effects; Medical sciences; Middle Aged; Mutagens; Nitrosation; Nitroso Compounds - metabolism; Tumors; Young Adult
• ISSN: 0143-3334; 1460-2180
• DOI: 10.1093/carcin/bgp130

Haem in red meat (RM) stimulates the endogenous production of mutagenic nitroso compounds (NOC). Processed (nitrite-preserved red) meat additionally contains high concentrations of preformed NOC. In two studies, of a fresh RM versus a vegetarian (VEG) diet (six males and six females) and of a nitrite-preserved red meat (PM) versus a VEG diet (5 males and 11 females), we investigated whether processing of meat might increase colorectal cancer risk by stimulating nitrosation and DNA damage. Meat diets contained 420 g (males) or 366 g (females) meat/per day. Faecal homogenates from day 10 onwards were analysed for haem and NOC and associated supernatants for genotoxicity. Means are adjusted for differences in male to female ratios between studies. Faecal NOC concentrations on VEG diets were low (2.6 and 3.5 mmol/g) but significantly higher on meat diets (PM 175 ± 19 nmol/g versus RM 185 ± 22 nmol/g; P = 0.75). The RM diet resulted in a larger proportion of nitrosyl iron (RM 78% versus PM 54%; P