Formation in vivo of volatile N-nitrosamines in man after ingestion of cooked bacon and spinach

In vivo formation of volatile N-nitrosamines in man after ingestion of a midday meal consisting of a bacon, spinach and tomato sandwich and beer is reported.

Abstract

N-NITROSAMINES, which are thought to be causally related to human cancer1, have been found in μg kg−1 concentrations in polluted air2,3, in water4 and in tobacco products5. Foodstuffs such as cooked bacon, preserved with nitrite, have long been known to contain μg kg−1 amounts of volatile N-nitrosamines formed during cooking6. In vivo formation of N-nitrosamines, after ingestion of suitable amine precursors and nitrite, has been demonstrated in laboratory animals7. In vivo formation in human subjects with hypoacidity, gavaged with relatively massive amounts of diphenylamine plus nitrite, has been demonstrated through detection of N-nitrosodiphenylamine in the stomach contents8. In vivo nitrosation after ingestion of conventional foods has not been demonstrated so far, either in animals or man. We now report in vivo formation of volatile N-nitrosamines in man after ingestion of a midday meal consisting of a bacon, spinach and tomato sandwich and beer.