Selenium reduced the chances of skin and bladder cancers, and slowed HIV, three new studies reveal.
Doctors in a skin cancer study thought antioxidants could protect the skin. Researchers measured blood levels of antioxidants, including selenium, in about 500 adults from Australia, where skin cancer rates are the highest in the world, and followed up for eight years. Compared to those with the lowest selenium levels, those with the highest selenium levels were 57 percent less likely to have basal cell carcinoma and 64 percent less likely to have squamous cell carcinoma, the two most common types of skin cancer.
In a bladder cancer study, researchers compared toenail selenium levels of about 770 people recently diagnosed with bladder cancer to 1,100 people from the general population. There was no overall difference between the two groups. But within three sub-groups—women, moderate smokers and those with a faulty cancer-suppressing gene (p53)—those with higher selenium levels were much less likely to have bladder cancer than were those with lower selenium levels. Doctors believe that the faulty p53 gene is a major pathway for bladder cancer and said, “If it is true that selenium can prevent a certain subset of individuals from developing bladder cancer or prevent certain types of tumors from developing, it gives us clues about how the tumors could be prevented...and could potentially lead to chemo-preventive efforts.”
In a human immunodeficiency virus (HIV) lab study, researchers explained that selenium forms an amino acid protein (selenoprotein) that reduces cellular stress from infection and thought it might slow the spread of HIV. Doctors believe that HIV depletes selenoproteins, allowing the virus to divide and spread rapidly in its early stages. Scientists infected normal human blood cell cultures with a strain of HIV-1, and then introduced a small amount of sodium selenite—the form selenium takes in the body—into the infected cells. HIV in cells treated with selenium grew 10 times more slowly than HIV in untreated cells.