How effective is selenium in preventing cancer?
Despite evidence for an inverse association between selenium exposure and the risk of some types of cancer, these results should be interpreted with care due to the potential limiting factors of heterogeneity and the influences of unknown biases, confounding and effect modification. Concerns have been raised about possible toxicities from long-term intake of supplemental selenium.
Selenium is a trace element essential to humans. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers.