Alcohol consumption does not lead to urinary excretion of N-nitrosodimethylamine in the fasting human

Abstract

To test the hypothesis that N-nitrosodimethylamine (NDMA) and possibly other nitrosamines are synthesized naturally in the gastrointestinal tract, the urinary excretion of nitrosamines has been measured in people whose first pass clearance and metabolism of nitrosamines had been inhibited by administration of ethanol. Five fasted volunteers consumed 350 mg of nitrate in beet juice followed, 1 h later, by a volume of 10% alcohol in carbonated water sufficient to raise their blood alcohol concentrations to 50-80 mg/100 ml. This alcohol concentration was then maintained over a 6 h period. No NDMA or any other volatile nitrosamines were excreted in urine during this 6 h period or during the subsequent 12 h (detection limit = 0.01 mumol). These results suggest that less than 0.5 mumol NDMA, formed by endogenous nitrosation in the fasting human, is likely to be present in the stomach at any time.