Does increased endogenous formation of N-nitroso compounds in the human colon explain the association between red meat and colon cancer?

摘要: High red meat diets have been linked with risk of sporadic colorectal cancer; but their effects on mutations which occur in this cancer are unknown. G-->A transitions K-ras and characteristic the alkylating agents such as N-nitroso compounds (NOC). We studied th effect consumption faecal NOC levels eight male volunteers who consumed low or high (60 600 g/day), beef, lamb pork, whilst living a metabolic suite. Increased intake induced significant (P<0.024) 3-fold increase from 40 + - 7 to ab average 113 25 microgram/day NOC, range exposure faeces similar that tobacco-specific cigarette smoke. THe were isoenergetic contained equal amounts fat, concentrations heterocyclic amines low. Faecal excretion promotor ammonia was significantly increased 6.5 1.08 mmol/day. When supplemented 20 g phytate-free wheat bran six there no reduction (mean 138 41 NOC), weight increased. Higher starch non-starch polysaccharide intakes reduced intraluminal cross-linking microcapsules (r=-0.77) pH (r=-0.64). In two white fish o diet 68 10 microgram/day, 56 -6 nor nitrate, nitrite iron. changing 46 mg/day, mean 80 mg/day.) endogenous production precursors meat, not fish, may be relevant aetiology cancer.