Nitrate and human cancer: a review of the evidence.
Fraser P., Chilvers C., Beral V., Hill MJ.
Nitrites, derived mainly from ingested nitrates, may react in vivo with secondary nitrogen compounds occurring naturally in certain foods to form N-nitroso compounds, which are potent carcinogens in laboratory animals. This paper reviews the mechanism of their formation and the evidence from epidemiological studies that high nitrate ingestion is involved in the aetiology of human cancer.