The potential benefits of selenium for prostate cancer prevention have generated a great deal of interest for a number of years.
At first, selenium was thought to be a beneficial nutrient by lowering the risk of prostate cancer. However, today we have much more information about the actual relationship between selenium and prostate cancer, and now know selenium is not useful.
Early Studies
Not that long ago, selenium was thought to provide some protection against the development of prostate cancer. Several observational studies had been performed, seemingly showing that higher intake of selenium was associated with a lower risk of prostate cancer.
In fact, multiple studies seemed to show that higher levels of selenium in the blood were correlated with lower risks of prostate cancer. Many major news organizations picked up on these stories, and soon much of the world thought of selenium as a potentially beneficial mineral for prostate cancer prevention.
Many prominent researchers pushed for a large, well-organized study of the true benefits of selenium for prostate cancer prevention.
The SELECT Trial
The SELECT (the Selenium and Vitamin E Cancer Prevention Trial) trial was the first large, well-organized, comprehensively controlled study that sought to evaluate the benefits of both selenium and vitamin E for prostate cancer prevention. The SELECT trial enrolled more than 35,000 men who were randomly assigned to one of four groups over the course of several years. One group took one selenium and one vitamin E tablet daily. Another group took one selenium and one placebo tablet daily. A third group took one vitamin E and one placebo tablet daily. The final group took two placebo tablets daily.
Overall, the SELECT trial showed no benefit in terms of prostate cancer risk reduction from taking selenium or vitamin E supplements.
Today
In large part due to the results of the SELECT trial, men today are generally no longer encouraged to take selenium and vitamin E supplements as a means to lower their prostate cancer risk.
Source:
Lippman SM, et al. Effect of Selenium and Vitamin E on Risk of Prostate Cancer and Other Cancers: The Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA. 2009;301(1):39-51
