Nitrates in the human diet - good or bad?

Although the nitrate and nitrite have been used for centuries, it has only recently been discovered that nitrate is manufactured in mammals by the oxi dation of nitric oxide and that the nitrate formed also has the potential f or disinfecting the food we eat. The mechanisms by which nitric oxide and o ther nitrogen oxides provide selective toxicity towards pathogens is not ye t completely understood, and it is likely that the mechanisms will be diffe rent with different organisms. Whereas it is clear that acidified nitrite i s produced on mucosal surfaces, and that this combination is effective in k illing a variety of human gut and skin pathogens, there is no definite evid ence as yet that this mechanism is truly protective in humans exposed to a contaminated environment. Further understanding of the complex chemistry of nitrogen oxides may also help develop new antimicrobial therapies based on augmenting what seems to be a simple and effective host defence system.