Researchers from IARC and Charité-Universitätsmedizin Berlin have investigated the importance of selenium in preventing cancer. Low levels were shown to be linked with increased risk of liver cancer.
Extoling the virtues of a selenium rich diet for Europeans and Americans, the researchers were concerned that a deficiency of selenium could be linked with many cancers (Journal of Clinical Nutritio; August 2016)
CANCERactive Founder and former Oxford University Biochemist, Chris Woollams added, "People reading this need to be careful. Many studies have come out of Germany on the benefits of Selenium. But. (And it may well be a big but.) It seems that three factors may be in play. First the type of selenium supplement (where some contain yeast and may be inappropriate); secondly, whether or not the person was deficient or already had adequate selenium levels; and finally what else was being studied.
For example with Prostate cancer, several studies have shown that men who are deficient in selenium can reduce their risk of cancer (1,2,3). But those who already have enough may actually increase their risk, Finally, while Natural Vitamin E and Selenium seem to be mutually beneficial, in the SELECT study the common over-the-counter synthetic alpha-tocopherol combined with selenium may increase rates of cancer. We have long warned people of this deficient compound purporting to be a vitamin".
References
(1) Lippman SM, Goodman PJ, Klein EA, et al. Selenium and vitamin E cancer prevention trial. JNCI 2005; 97(2):94-102.
(2) Lippman SM, Klein EA, Goodman PJ, et al. Effect of selenium and vitamin E on risk of prostate cancer and other cancers. JAMA 2009; 301(1). Published online December 9, 2008. Print edition January 2009.
(3) EA Klein, IM Thompson, CM Tangen, et al. Vitamin E and the Risk of Prostate Cancer: Results of The Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA 2011; 306(14) 1549-1556.