by Dr. House
Selenium Toxicity from overconsumption of Brazil Nuts, called selenosis, was "reported" on an episode of Dr. House, a medical TV show that often takes artistic liberties to enhance entertainment value. In reality, there has never been a reported case of Selenosis from ingesting Brazil nuts. This is merely one example of many egregious errors and biases against natural medicine on the Dr. House series. This is to be expected, considering the massive drug company advertising supporting the show. This article will examine the case for selenium as a cancer preventive.
Above Left Image: Dr Gregory House Courtesy of Wikimedia
Evidence that Selenium Prevents Prostate Cancer
Selenium Prevents Prostate Cancer in Genetic Mice
An elegant study from the University of Illinois in the 2006 Proceedings of the Nat Academy of Science used mice that were genetically manipulated to have both a selenoprotein deficiency, and an increased prostate cancer incidence. The selenoprotein-deficient mice exhibited accelerated development of prostate cancer in the form of prostate intra-epithelial neoplasia with microinvasion. This study clearly implicated selenoprotein deficiency as a risk factor for prostate cancer, and selenium as a preventive agent.(2)
Yet another transgenic mouse prostate cancer study published in May 2009 AACR by Wang et al showed inhibition of prostate cancer and increased survival in mice treated with selenium compounds.(3)
Left Image: L-selenocysteine, the most biologically active selenium dietary supplement, courtesy of wikimedia commons
Selenium Prevents Colon Cancer in Genetic Mice
Irons et al published a study in the 2006 Journal of Nutrition by evaluating colon cancer in genetically altered mice, deficient in selenoproteins. The mice were given dietary selenium, and the colon was studied for cancer formation. The mice supplemented with dietary selenium had reduced colon cancer, with fewer pre-neoplastic lesions of the colon, This was true for both seleno-protein deficient mice as well as normal mice. (4)
A second colon cancer study in mice from India published in the 2009 World Journal of Gasteroenterology showed that dietary selenium supplements reduced colon cancer tumors by 40 % in mice chemically treated with carcinogens to induce colon cancer.
Selenium Levels PredictBreast Cancer Risk
A study published in 1985 in Japan Cancer Research looked at serum selenium levels in American and Japanese women with breast cancer. Healthy Japanese women had higher selenium levels of 286 mcg/ml compared to Japanese women with breast cancer who had lower selenium levels of 195 mcg/dl. For healthy American women, serum selenium was higher at 191 compared to American women with breast cancer who had lower selenium of 167 mcg/ml. (6)