Bladder cancer affects the inner lining of the bladder and, according to U.K. health care provider Bupa, mostly affects people older than 50. The exact cause of bladder cancer is not completely understood, but smoking, repeated bladder infections and exposure to environmental pollutants increase the risk of developing this form of cancer. Treatment usually includes surgery to remove the tumor, immunotherapy or chemotherapy. Selenium might also play a role in the treatment and prevention of bladder cancer, although evidence to prove this is mixed. Talk to your doctor before taking selenium supplements.
Properties and Potential Benefits
Selenium is a mineral the body incorporates into proteins that help protect cells from damage by free radicals. It also plays a role in thyroid function, supports the immune system, and might play a role in the prevention and treatment of a number of ailments, including arthritis and HIV. The Office of Dietary Supplements adds that it might also prevent cancer tumor growth by boosting immune cell activity and stopping the development of blood vessels that supply the tumor.
Effectiveness
Evidence showing that selenium helps prevent bladder cancer is mixed. The results of a study published in the September 2010 issue of "Cancer Epidemiology, Biomarkers and Prevention" show that high selenium intake reduces the risk of bladder cancer risk, particularly in women. The authors note, however, that additional studies are needed to confirm these effects. In contrast, the results of a study published in the January 2009 issue of "Cancer Prevention Research" show that overall, selenium intake is not associated with a lower risk of bladder cancer, although it might be beneficial for smokers and women.
Sources and Administration
The Office of Dietary Supplements notes that plant foods are the major dietary sources of selenium, although fish, meat, cottage cheese, spaghetti and eggs also contain selenium. It is also available as a dietary supplement. Guidance regarding a suitable dose to help prevent or treat bladder cancer is lacking, although your pharmacist or doctor might be able to advise you. Don't take more than 400 micrograms of selenium daily, the upper tolerable limit for adults, unless your doctor has approved it.
Safety Considerations
The Memorial Sloan-Kettering Cancer Center says taking more than 1,000 mcg of selenium daily might cause selenosis, a condition characterized by mild nerve damage, muscle weakness, garlic breath and hair loss. It might also reduce the absorption of vitamin C. Get medical clearance before taking selenium supplements and always read the supplement label carefully.
References
- Bupa: Bladder Cancer
- Office of Dietary Supplements: Selenium
- "Cancer Epidemiology, Biomarkers and Prevention"; "Selenium and Bladder Cancer Risk: A Meta-Analysis"; A.F. Amaral et al; September 2010
- "Cancer Prevention Research"; "Selenium and Risk of Bladder Cancer: A Population-Based Case-Control Study"; K. Wallace et al; January 2009
- Memorial Sloan-Kettering Cancer Center: Selenium
