Nitrates and nitrites have been used for years as preservatives and flavouring for processed meat such as hotdogs, salami and other sausages. But a recent study gives some indications that these food grade chemicals may be partly responsible for increased risk for bladder cancer.
In the US, about 70,000 cases of the cancer of the urinary bladder are diagnosed each year. The most common symptom of the disease is hematuria (blood in the urine), sometimes accompanied by stress incontinence (urine leakage during physical exertion and coughing). However, rare cases of bladder cancer have been diagnosed despite the absence of blood in the urine.
Researchers at the National Cancer Institute in Rockville, Maryland looked at 300,933 people from all over the US as part of a study that began in 1995. The study participants were followed up for 7 years and within this period, 854 were diagnosed with bladder cancer, an incidence of 0.3%. This may seem low but estimates indicate that longer follow-ups would witness a rise in incidence, with 2% of the population expected to develop bladder cancer in their lifetime.
The incidence of bladder cancer was linked to eating processed meat, with those ranked in the top 5th in terms of processed red meat consumption having a 30% increased risk for bladder cancer than those in the bottom 5th of the of the consumption rankings. But it is not only the processed meat but other food stuffs containing the additives nitrites and nitrates that are linked to bladder cancer risk.
Previous reports have linked processed meat consumption to gastrointestinal cancers. But how do nitrates and nitrites get into the urinary bladder to cause cancer? According to a Reuters report:
“During the cooking process, nitrites and nitrates combine with other chemicals that are naturally present in meat to form potentially cancer-causing N-nitroso compounds [heterocyclic amines or polycyclic aromatic hydrocarbons], which may then be excreted through the urinary tract where they can contact the lining of the bladder.”
But take note that it is not only these food additives that can increase your risk. There are other carcinogens in our environment as well that may have an additive impact. Besides, red meat processed or not, is linked to a lot of health problems, from cancer to cardiovascular disorders. According to a 2007 World Cancer Research Fund and American Institute for Cancer Research report, we should “limit consumption of red meats (such as beef, pork and lamb) and avoid processed meat (ham, bacon, salami).”