Current Trends Pertaining to Supplementation and Prostate Cancer Risk (August 2014)

What is a man supposed to do? Many men are trying to be proactive taking supplements to reduce their chances of developing prostate cancer due to aging, their family history, and are becoming more aware of prostate cancer from the data they have read.

A multicenter study led by the Fred Hutchinson Cancer Research Center has found that by taking a dose supplementation with both the trace element selenium and Vitamin E increase the risk of high-grade prostate cancer. This risk depends on a man’s selenium status before taking the supplements.

The results were published in the Journal of the National Cancer Institute, and are based on the Selenium and Vitamin E Cancer Prevention Trial (SELECT); a rigorously executed, randomized placebo- controlled trial conducted by SWOG cancer research cooperative group that  involved more than 35, 000 men.  The study went to determine whether taking high-dose vitamin E (400 IU/day) and/or selenium (200 mcg/day) supplements could protect men from prostate cancer.

The trial started in 2001 and was designed to last 12 years, but stopped in 2008 because it found no protective effect from selenium, and it was suggested that Vitamin E increased cancer risk. Men were still followed although the use of the study supplements stopped. After an additional two years, the men who took vitamin E had a significant 17% increased risk for developing prostate cancer.

When the study began there was some evidence that selenium supplementation wouldn’t benefit men who already had an adequate intake of the nutrient.   Researchers then measured the concentration of selenium in participants’ toenails and planned to test whether selenium supplementation would help only this group of men with low selenium levels at baseline. Instead, they found that taking selenium supplements increased the risk of high level cancer up to 91% among men with high selenium status at baseline.  When men took selenium levels that were already high their blood levels became toxic.

The study also showed that this subgroup of men also were at high risk for developing prostate cancer when taking vitamin E. Men with low selenium status who were baseline, found that vitamin E supplementation increased their total risk of prostate cancer by 63% and increased the risk of high level cancer by 111%. This concluded one of the original SELECT findings, which was that only men who received vitamin E plus a placebo pill, and not those who received both vitamin E and selenium, had an increased prostate cancer risk.  Selenium, whether from dietary sources or supplements, protected men from the harmful effects of vitamin E.

The bottom line is that the study showed no benefits to any of the men from either individual supplements being selenium or vitamin E, and for significant proportions of men in the study these supplements were harmful. There does not appear any risk by taking a multivitamin and these vitamins are included in a multivitamin which is not a problem.   There are ideal levels which can often be consumed from a healthful diet but either above or below the recommended amount could pose a potential risk according to the Fred Hutchinson Cancer Research Center.

Researchers at UCLA found that men with prostate cancer who ate a low fat diet and who took fish oil supplements had lower levels of anti-inflammatory substances in their blood as well as a cell progression score. This was in comparison to men who ate classic Western diet UCLA researchers concluded. Slowing down the cell cycle progression (CCP) is important as this may prevent prostate cancers to become more aggressive. Lead author William Aronson, MD from the Department of Urologic Oncology at the VA Medical Center in Los Angeles reports that “men who consumed a low fat diet and took fish oil had lower CCP scores”.

This study appeared in the online edition of Cancer Prevention Research which is a peer reviewed journal of the American Association for Cancer Research.

The study is a follow up to a study that Aronson and his team completed last year where the participants consumed a low fat diet with fish oil for four to six weeks before prostate removal.  The growth of cancer cells in human prostate cancer tissue were compared to a high fat Western diet.

In conclusion, as I say to my clients: learn how to eat in moderation instead of being extreme about anything, since we know that diet and trends are always changings. It’s nice to see what the science actually shows us.