There have been some recent research results relating to selenium supplementation and prostate gland tissue. Researchers in The Netherlands have published results showing that a five-week daily intervention with a high-selenium yeast supplement, 300 micrograms daily, is associated with a down-regulation of genes that are involved with cellular growth and proliferation, with cellular immune response, and with inflammation processes. Also down-regulated by the selenium supplementation is the activity of genes involved with wound-healing [Kok 2017].
The Dutch study was a randomized, double-blinded, placebo-controlled study. Interestingly, the researchers saw the opposite effect in the placebo group. In the placebo group, there was an up-regulation of the genes involved in cellular immune response [Kok 2017].