Influence of dietary nitrate on nitrite content of human saliva: Possible relevance to in vivo formation of N-nitroso compounds

There is a direct relationship between the salivary nitrite concentrations and the amounts of nitrate ingested in the diet, and the possible relevance of these findings to the endogenous formation of N-nitroso compounds in the gastro-intestinal tract is discussed.

Abstract

Vegetables and vegetable juices with concentrations of nitrate between 27 and 4031 ppm were ingested by 11 volunteers in 30 experiments. Variations of nitrate and nitrite concentrations in saliva were determined for up to 7 hr at intervals of 30 or 60 min. The increase in the amount of nitrate secreted by the salivary glands was found to depend directly on the amount of nitrate ingested. Nitrite concentration in saliva correlated directly with salivary nitrate content. This suggests that there is a direct relationship between the salivary nitrite concentrations and the amounts of nitrate ingested in the diet. The average increase of nitrite concentration in saliva was 20 ppm/100 mg nitrate ingested. The possible relevance of these findings to the endogenous formation of N-nitroso compounds in the gastro-intestinal tract is discussed.