Studies have now also shown that pregnant women who eat a single hot dog per week are likely to give birth to a child that will develop a brain tumor.
What is the problem?
Nitrites and nitrates are used as preservatives in cured meats such as bacon, salami, sausages and hot dogs. Nitrites, which can form from nitrates, react with naturally occurring components of protein called amines. This reaction can form nitrosamines, which are known cancer-causing compounds. Nitrosamines can form in nitrite or nitrate-treated meat or in the digestive tract.
Studies have linked nitrites to stomach cancer (IARC 2010). Some data also suggest an association with cancer of the esophagus; one study showed an increased risk in people who eat cured meats more often (Rogers 1995; Mayne 2001).
There is also evidence that nitrites may be associated with brain and thyroid cancers, but a causal link has not been established (Preston-Martin 1996; Pogoda 2001; Aschebrook-Kilfoy 2013; IARC 2010).
In 2010, scientists at the World Health Organization’s International Agency for Research on Cancer declared that ingested nitrites and nitrates are probable human carcinogens.
The California Office of Environmental Health Hazard Assessment is currently considering listing nitrite in combination with amines or amides as a known carcinogen.
Some nutritious foods such as spinach and other leafy vegetables are naturally high in nitrates, but human studies on nitrate intake from vegetables have found either no association with stomach cancer or a decreased risk (IARC 2010).