Nitrosamine health danger
January 17 2016

Nitrosamines are chemical compounds, most of which are carcinogenic, and are produced when the food preservative nitrite combines with amino acids in the stomach. Nitrate is used mainly in inorganic fertilizers, and sodium nitrite is used as a food preservative, especially in cured meats. The compounds are also found in cheese products, beer and water. Exposure also occurs through manufacturing and processing of rubber and latex products, as well as fertilizers, pesticides and cosmetics.

There appears to be a link between increased levels of nitrates in the environment and in food and increased deaths from Alzheimer's, Parkinson's and Type 2 diabetes. There has been an increases in human exposure to nitrates and nitrosamines through processed and preserved foods, as well as through fertilizers. "We have become a nitrosamine generation," says researcher Dr. Suzanne de la Monte of Rhode Island Hospital. "In essence, we have moved to a diet that is rich in amines and nitrates, which lead to increased nitrosamine production. Nitrites and nitrates belong to a class of chemical compounds that have been found to be harmful to humans and animals." Dr. Suzanne de la Monte adds, "More than 90 per cent of these compounds that have been tested have been determined to be carcinogenic in various organs."

Environ Sci Technol. 2012. Halonitroalkanes, halonitriles, haloamides, and N-nitrosamines: a critical review of nitrogenous disinfection byproduct formation pathways. Interest in the formation of nitrogenous disinfection byproducts (N-DBPs) has increased because toxicological research has indicated that they are often more genotoxic, cytotoxic, or carcinogenic than many of the carbonaceous disinfection byproducts (C-DBPs) that have been a focus for previous research. Moreover, population growth has forced utilities to exploit source waters impaired by wastewater effluents or algal blooms. Both waters feature higher levels of organic nitrogen, that might serve as N-DBP precursors. Utilities are exploring new disinfectant combinations to reduce the formation of regulated trihalomethanes and haloacetic acids. As some of these new combinations may promote N-DBP formation, characterization of N-DBP formation pathways is needed. Formation pathways for halonitroalkanes, halonitriles, haloamides, and N-nitrosamines associated with chlorine, ozone, chlorine dioxide, UV, and chloramine disinfection are critically reviewed. Several important themes emerge from the review. First, the formation pathways of the N-DBP families are partially linked because most of the pathways involve similar amine precursors. Second, it is unlikely that a disinfection scheme that is free of byproduct formation will be discovered. Disinfectant combinations should be optimized to reduce the overall exposure to toxic byproducts. Third, the understanding of formation pathways should be employed to devise methods of applying disinfectants that minimize byproduct formation while accomplishing pathogen reduction goals. Fourth, the well-characterized nature of the monomers constituting the biopolymers that likely dominate the organic nitrogen precursor pool should be exploited to predict the formation of byproducts likely to form at high yields.

Bladder cancer
Dr. Dominique S. Michaud of the Harvard School of Public Health in Boston and her colleagues found that people who ate bacon five times a week or more were nearly 60-percent more likely to develop bladder cancer, while those who ate skinless chicken this frequently had a greater risk of the disease. Some meat products contain nitrosamines, which are known to cause bladder cancer. Michaud and her team looked at data for 47,422 men and 88,471 women participating in the Health Professionals Follow-Up Study and the Nurse's Health Study, respectively. Participants were followed for up to 22 years, during which time 808 developed bladder cancer. People who ate bacon and other processed meats frequently were also more likely to smoke and to take in more fat and fewer vitamins. They were also less likely to exercise. The association between the total meat consumption and bladder cancer was not statistically significant. But those who ate bacon five or more times per week were 59-percent more likely to develop bladder cancer than those who never did. Also, men and women who ate chicken this often were more likely to develop bladder cancer than those who never ate skinless chicken. Compared with skinless chicken, cooked chicken with skin is known to contain a smaller amount of heterocyclic amines, carcinogenic compounds that form when meat is cooked at high temperatures. The researchers suggest that nitrosamines, heterocyclic amines, or both are responsible for the health effects of bacon seen in the current study.  American Journal of Clinical Nutrition, 2006.

The hypothesis that nitrosamine exposure may increase the risk of glioma has been circulating for several decades, but testing it has been difficult because of the ubiquitous nature of nitrosamine exposure. Diet has been the focus of many studies because it can substantially influence nitrosamine exposure, mostly from the endogenous formation of nitrosamines based on intake of nitrite and nitrate. In one study, there was no suggestion that intake of meat, nitrate, nitrite, or nitrosamines is related to the risk of glioma. American Journal of Clinical Nutrition, September 2009.

Stomach or intestinal cancer
The potential associations between dietary consumption of nitrates, nitrites, and nitrosamines and gastric cancer risk have been investigated by several studies, but yielded inconclusive results.