However, an updated analysis appearing in JAMA: The Journal of the American Medical Association demonstrates that vitamin E supplementation may significantly increase the risk for prostate cancer. Men who received a common dose of vitamin E had a 17% increased risk for prostate cancer when compared to men who only took a placebo.
According to the authors, this observed increase in risk demonstrates “the potential for seemingly innocuous yet biologically active substances such as vitamins to cause harm.”
Lead author, Laurence Baker, DO, professor of internal medicine and pharmacology at the University of Michigan, claims that the findings were unexpected. He stated, “Vitamin E doesn’t prevent prostate cancer; it doesn’t prevent any cancer, despite the claims of some, and it doesn’t promote cardiovascular health, despite the claims of many.”
The SELECT trial was initially conducted based on the premise that selenium and vitamin E supplementation might reduce prostate cancer risk. This hypothesis was based on preclinical and epidemiological studies that implied there might be a benefit. However, the use of the 2 supplements was stopped in October 2008 since there was an apparent lack of benefit and a possibility of harm.
The trial involved over 35,000 healthy men from 427 study sites in the United States, Canada, and Puerto Rico who were randomized from 2001 and 2004. All participants had healthy levels of prostate-specific antigen, a cleared digital examination for prostate cancer, and were 50 years of age or older.
The men were randomly placed into 4 treatment groups. One group received selenium, one group received vitamin E, one group received both compounds, and the last group received placebo. After five years of follow up, the results indicate that the rate of prostate cancer detection was higher in all groups that received a compound, but only the vitamin E group had risk that reached statistical significance.
Associate professor of medicine at Harvard University Medical School, Matthew Smith, MD, PhD, believes that this study emphasizes the importance of scrutinizing claims attributed to over-the-counter products. He states, “The cautionary part is that if you look at the background information, it is a compelling narrative. Unfortunately, the definitive trial has now been done, and it shows it is not true.”