Survey of human milk for volatile N-nitrosamines and the influence of diet on their formation.

Human milk was analysed for volatile N-nitrosamines and the influence of diet on their possible presence and formation was assessed. 175 samples were obtained from 16 different nursing women. Analysis of samples collected at random, to ascertain baseline levels, indicated that 76.5% of the human milk samples contained less than 0.2 ppb N-nitrosodimethylamine (minimum level of reliable measurement). No other volatile nitrosamines were detected. Expressed milk was collected from volunteers over a 6-hr period after eating meals which included bacon (a source of performed nitrosamines) and at times a vegetable high in nitrate. Eating a meal containing bacon did not result in increased nitrosamine levels in milk. In certain individuals, eating a meal of bacon and a vegetable high in nitrate occasionally resulted in higher levels of N-nitrosodimethylamine in their milk.