STANFORD, CALIFORNIA. Several large studies have shown that men with low blood (plasma) levels of selenium have a significantly increased risk of prostate cancer. Now medical researchers at Stanford University and the Johns Hopkins University School of Medicine weigh in with another report that clearly shows the protective effect of selenium. Their study involved 52 men diagnosed with prostate cancer and 96 age-matched controls with no detectable prostate disease. The men had an average age of 69 years and were all enrolled in the Baltimore Longitudinal Study of Aging. Plasma levels of selenium measured in blood samples taken four to five years prior to the diagnosis of prostate cancer were compared for cancer patients and controls. The researchers found that men with selenium levels below 10.7 micrograms/dL had a four to five times higher incidence of prostate cancer than did men with levels above 10.7 micrograms/dL. They also noted a significant decline in selenium levels with age.
The researchers believe that much of the beneficial effect of selenium is due to its vital role in maintaining
adequate levels of the body's main antioxidant, glutathione peroxidase. They conclude that selenium
supplementation may reduce the risk of prostate cancer and that supplementation may be particularly
important for older men. NOTE: The recommended daily intake of selenium is 55 micrograms with an upper
safe limit of 400 micrograms/day. However, most supplementation studies have used 200