In the 2011 JAMA Network study, researchers revisited findings from an earlier trial that showed selenium and/or vitamin E supplementation did not lower prostate cancer risk, but instead, demonstrated an increased risk for the disease albeit one that was considered statistically nonsignificant. The research involved more than 35,500 healthy men who were either given selenium supplements in combination with a vitamin E placebo, vitamin E supplements with a selenium placebo, both supplements, or both placebos. Participants were monitored over the course of 7 to 12 years. The study findings showed that vitamin E supplementation significantly increased men’s susceptibility to prostate cancer. However this risk was not seen in those who received both vitamin E and selenium supplements, indicating that selenium may counteract vitamin E’s potential negative effects on prostate cancer risk.
Researchers from a 2019 laboratory study published in Scientific Reports decided to take a closer look at what could potentially be going on behind the scenes regarding vitamin E and prostate cancer risk. What they found was that vitamin E appeared to have cancer-promoting effects, such as stimulating cell transformation, and promoting DNA damage due to enhanced oxidative stress.