Authors of a recent meta-analysis of 69 studies of selenium exposure and cancer risk have concluded that high selenium exposure can reduce cancer risk, especially high selenium exposure that is reflected in high plasma or serum selenium status and/or in high toenail concentrations [Cai 2016]. Admittedly, higher selenium intakes (as compared to lower selenium intakes) can affect different forms of cancer differently. We still need more research to sort out which forms and dosages of dietary and supplemental selenium are most effective at reducing cancer risk. In this article, I want to summarize the findings of Dr. Xianlei Cai and colleagues.
What is a meta-analysis of selenium exposure and cancer risk?
A meta-analysis is a research method of combining the data from several selected research studies to reach conclusions that have greater statistical power. In the present case, Cai et al selected 69 studies that met their inclusion criteria. Each one of the 69 selected studies had the following characteristics: