WASHINGTON (Reuters) - Selenium and vitamin E supplements do not prevent prostate cancer and may in fact be a little bit dangerous, U.S. researchers reported on Monday.
The study of 35,000 men showed the supplements did not work together or alone to prevent prostate cancer, the most common type of cancer in men in the United States.
“As we continue to monitor the health of these 35,000 men, this information may help us understand why two nutrients that showed strong initial evidence to be able to prevent prostate cancer did not do so,” Dr. Eric Klein of the Cleveland Clinic in Ohio, who worked on the study, said in a statement.
Other, earlier studies had suggested that the two supplements might prevent prostate cancer. Both are antioxidants — compounds that interfere with chemical reactions that can damage cells and DNA.
The National Cancer Institute, which helped organize the study, said men taking part are being told to stop taking the supplements they had been given but will continue to have their health monitored for about three more years.
“The data also showed two concerning, but not statistically significant, trends: there were slightly more cases of prostate cancer in men taking only vitamin E and slightly more cases of diabetes in men taking only selenium,” the NCI, one of he National Institutes of Health, said in a statement.
“Neither of these findings proves an increased risk from the supplements and may be due to chance. “
The men in the study were randomly assigned to take one of four sets of supplements or placebos, with one group taking both selenium and vitamin E; one taking selenium and a placebo; one taking vitamin E and a placebo; and the final group getting two dummy pills.
The American Cancer Society predicts that in 2008, an estimated 186,320 men will be diagnosed with prostate cancer and 28,660 will die from it in the United States alone.
Reporting by Maggie Fox; Editing by Julie Steenhuysen and Cynthia Osterman