Vitamin E and Selenium No Help in Preventing Prostate Cancer

Vitamin E and selenium supplements do nothing to help prevent prostate cancer. In fact, there is some evidence of increased risk for the disease when taking vitamin E.

National Cancer Institute researchers have reported that they are halting a significant portion of a major study to determine whether vitamin E and selenium may help to prevent prostate cancer. Until now, over 35,000 men ages 50 and older have been taking either or both supplements or a placebo in the study known as the SELECT trial.

The National Cancer Institute (NCI) announced that letters are being sent out to instruct study participants to cease taking the supplements due to results of an early review of the data indicating that neither supplement, whether taken alone or together, is preventing prostate cancer. In fact, the data results suggest that a few more of those men taking vitamin E alone were actually getting prostate cancer, while slightly more participants taking only selenium were developing diabetes. The NCI stressed that the results of the review are not statistically significant and do not constitute proof of any risk created by taking the supplements. It may merely be a coincidence.

In prior small studies, results hinted that vitamin E and selenium might help in the fight against prostate cancer since they are antioxidant compounds that interfere with chemical reactions that can damage cells and DNA. This led researchers to pursue more large-scale studies in determining the truth about the possibilities. The failure of the nutrients to reduce the risk for the disease has now become just another disappointment in the struggle to find dietary preventative measures against prostate cancer as well as other medical conditions.

Other studies of antioxidants and nutritional supplements have failed to confirm benefits for various conditions, and several have proven them to be harmful. Examples of this include a studies showing that beta-carotene increases instead of decreases the risk of lung cancer among smokers, and findings establishing that vitamin E actually raises the risk for heart disease when it had previously been believed to have preventive effects.

The study participants will be continue to be followed by researchers for yet another three years to track their health as well as to perform previously scheduled blood tests. Since participants did not know whether they were taking one or both nutrients or placebo, as always is the case in blind studies, they will now be told if they ask their doctors. However, the researchers say that the results of the study will be more accurate if the majority of the men wait until follow-up is complete to get their answers.

In a statement, Dr. Eric Klein of the Cleveland Clinic in Ohio, who worked on the study, said, “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. Klein also noted, “The important message for consumers is that taking supplements, whether antioxidants or others, is not necessarily beneficial and could be harmful.” He went on to explain, “You should not be taking them unless there is a rigorous scientific study that shows a benefit.”

In the U.S., prostate cancer is the most common form of cancer among men next to skin cancer. According to the American Cancer Society, the disease will strike an estimated 186,320 men this year and claim 28,660 lives. The cause of prostate cancer is not known and there is currently no real cure, although the disease can be well managed in many cases. Some research has shown that finasteride, a drug that is currently used for an enlarged prostate, can help to prevent prostate cancer, yet side effects limit its use.