People who consume a large amount of nitrite and nitrate from processed meat may be at an increased risk for developing bladder cancer, according to a study published in Cancer.
Bladder cancer is diagnosed in as many as 60,000 individuals annually in the United States. It is much more common in elderly individuals. Bladder cancer has high cure rates if detected and treated early; however, these cure rates fall dramatically once the cancer has spread to different sites in the body. As with all types of cancer, the best “treatment” of bladder cancer is to prevent its occurrence in the first place. Thus, researchers continue to evaluate potential risk factors for the disease.
It has been suspected that consumption of meat may increase risk for bladder cancer. More specifically, compounds that are related to the cooking and processing of meat are being investigated as potential risk factors. These compounds include nitrate and nitrite, which are added to processed meat for preservation and enhancement of color and flavor.
Researchers associated with the National Institutes of Health and AARP investigated the association between meat and meat components and bladder cancer risk. Information on lifestyle and dietary habits was collected from over 300,000 individuals in the United States. At a follow-up of eight years, 854 participants had been diagnosed with bladder cancer.
When looking at broad categories of meat (red, white, or processed), there was no clear link between meat intake and bladder cancer risk. There was, however a suggestion of an increased risk of bladder cancer among those who consumed the highest level of red processed meat, as well as among those who consumed the highest level of red meat cold cuts.
Participants with the highest level of dietary nitrite from all sources (not only processed meat) had a 28% increased risk of bladder cancer compared with those with the lowest intake. Risk was increased to a similar extent (29%) among those with the highest intake of nitrate plus nitrite from processed meat. This latter finding was of borderline statistical significance, suggesting that it could have occurred by chance alone.
The researchers concluded that these findings provided “modest support” for a link between bladder cancer and total dietary nitrite and nitrate plus nitrite from processed meat. Further study into these associations is warranted.
Reference: Ferrucci LM, Sinha R, Ward MH, et al. Meat and components of meat and the risk of bladder cancer in the NIH-AARP Diet and Health Study. Cancer [early online publication]. August 2, 2010.