Three supplements thought to help reduce the risk of prostate cancer, vitamin E, selenium and soy, have proven ineffectual, according to a new study published in the Journal of Clinical Oncology.
Researchers with the University Health Network in Toronto performed a three-year, double-blind study of 303 men who were already at increased risk of developing prostate cancer.
The men were randomly assigned to either take the three supplements or a placebo. Those taking the supplements were given well over the recommended daily dose.
Follow-up prostate biopsies were then performed at the six, 12, 24, and 36-month mark.
After three years, no beneficial effects were seen in the men taking the supplements. In both groups, 26 percent of participants developed the cancer.
"To our chagrin, there was no benefit," said lead author Dr. Neil Fleshner, who admitted there had been high hopes the supplements would work.