Selenium Supplements and Prostate Cancer

Filed Under: Men's Health

Selenium Supplements and Prostate Cancer

Here’s some important prostate cancer news that I want to share with you. New findings just released from the Selenium and Vitamin E Cancer Prevention Trial (SELECT) showed that for some high-risk men, a high-dosage of selenium supplements can be risky for the prostate.

What Is the SELECT Trial?

It’s the same trial I told you about a while back about vitamin E and prostate cancer risk factors.  For that investigation, researchers gave participants 400 IU of vitamin E and/or a 200 mcg selenium supplement to see if high doses of these nutrients could reduce the prostate cancer risk factors. But when they followed up with participants, the researchers discovered that the men in the study had an increased risk of developing prostate cancer. That’s why the study was terminated in 2008. But the researchers continued to follow up with the participants regarding their prostate cancer risk factors.

As for the results, the vitamin E portion of the trial confirmed what I already knew: that giving participants a high dose of a single form of vitamin E has a pro-oxidant effect on the body. That’s why I recommend taking vitamin E with some mixed tocopherols for balance. It’s far safer and more effective than taking just one form of vitamin E alone.

The New Selenium Supplement Findings Do Concern Me

What the researchers found is that men who had high selenium levels at the beginning of the study, as measured from toenail clippings, had a 91 percent greater risk of developing “high-grade prostate cancer.” Yet, even the researchers admitted that this method may not be an accurate way to measure selenium levels.

What’s also important is that the researchers didn’t give vitamin C to the study participants—just vitamin E and a selenium supplement. Yet, selenium requires vitamin C to make glutathione peroxidase, which is an antioxidant that gives very strong support to the immune system

Vitamin C also prevents the dangerous pro-oxidant effect that vitamin E has on HDL cholesterol—and HDL cholesterol is vital for immune system support. Plus, it’s important to remember that it’s the immune system that keeps developing cancer cells in check. I think the results of the SELECT trial—and the prostate cancer news following it—could have been very different if they had given the study participants vitamin C.

The Bottom Line on Selenium Supplements 

Selenium is a vital nutrient for the immune system. But if you’ve been diagnosed with prostate cancer through a biopsy, or have a high PSA score or prostate nodules, I would follow the “precautionary principle”—meaning I would err on the side of safety.

Even though the research is flawed, there are some good takeaways. The main one is that when it comes to selenium, perhaps less is more. This means that if you have any of these serious prostate issues, I would not take a high-dose selenium supplement—meaning 200 mcg of selenium or more daily. But again, this study raises many more questions than answers. Certainly more research needs to be done. 

Now it’s your turn:
 What are your thoughts on this study and selenium supplements?

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DISCLAIMER: The content of is offered on an informational basis only, and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified health provider before making any adjustment to a medication or treatment you are currently using, and/or starting any new medication or treatment. All recommendations are "generally informational" and not specifically applicable to any individual's medical problems, concerns and/or needs.

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