Cured meats (luncheon meats, hot dogs, bacon) contain nitrites. Uncured meats and organic meats do not. Nitrite is used to cure meat because it prevents bacterial growth and gives the meat a red color. However, nitrites in meat can react with degradation products of amino acids, forming nitrosamines, which are known carcinogens.
A recent study conducted through Columbia University examined the possible relationship between nitrite consumption and lung disease (Jiang, 2007) because previous studies found that rats fed nitrites developed emphysema (Shuval, 1972). Nitrites in tobacco smoke are thought to be a major contributor to lower lung function in smokers.
The study population consisted of approximately 10,000 people aged 45 years or older. Younger people were unlikely to have obstructive pulmonary disease, and so were excluded. Study participants were questioned about their cured meat consumption, and their lung functions were measured. The frequency of cured meat consumption was positively associated with reduced lung function after adjusting for confounding factors such as smoking status and smoking history. Other dietary factors were also adjusted. Previous studies have shown a reduced risk of obstructive lung disease in people who consumed more fish, fruits, vegetables, and antioxidant vitamins. Even after these adjustments the results showed both a reduction in measured lung function and an increased risk of obstructive pulmonary disease in those study participants who consumed the most cured meats compared with those who ate less cured meats.
This and other studies should serve to warn consumers about the increased danger of nitrites in cured meats. I would be especially concerned about anyone with lung disease such as asthma or a weakness in lung function and increased susceptibility to coughs and chest colds. Uncured meats are readily available at health food groceries. Remember also that organic meats are best because pesticides consumed by animals tend to be concentrated in the fats.
Jiang R, et al. Cured meat consumption, lung function, and chronic obstructive pulmonary disease among United States adults. American Journal of Respiratory and Critical Care Medicine 2007 (April); 175:798-804.
Shuval HI, Gruener N. Epidemiological and toxicological aspects of nitrates and nitrites in the environment. American Journal of Public Health 1972; 62:1045-1052).