A new study at Harvard Medical School has given indisputable evidence linking prostate cancer to low levels of Selenium in the diet. The study compared 181 men with advanced prostate cancer with 181 men of similar age with no cancer. They found that men with the highest Selenium intake (159mcg per day, more than twice the RDA) had half the risk of developing prostate cancer. Men getting around 200mcg of Selenium per day for about 4-5 years also had reduced risks of lung and colon and rectal cancer.