Moderation is key for most things in life, and selenium is certainly one of them. This element is critical to many life forms, including humans, but becomes toxic when doses are too high, so it’s a delicate balancing act that nature has mostly perfected.
Rare in Purity
Selenium occurs in two forms at its pure state: a silvery metal that shapes itself into pellets, and a deep red powder. Despite being somewhat common in certain plants and foods, selenium only occurs in a few rare minerals.
Even so, brazil nuts and garlic often have high levels of selenium due to the fact that they glean quite a bit of the element from the soil in which they’re grown, particularly if that soil is especially rich with selenium.
Jons Jacob Berzelius first isolated selenium in 1817, and the element was thought to be toxic for nearly 150 years after that initial discovery. Indeed, it was this assumption that led scientists to discover selenium’s medical prowess.
Cancer Fighting Properties
In the 1960s, doctors began studying whether or not selenium, like chemo, could be used to fight tumors due to its toxicity. They found that the element could actually help protect against cancer, but the dosage must be extremely precise or toxicity can occur.
Additionally, selenium is used to colorize glass and is an additive used to create stainless steel. The coloring comes from the amorphous, red form of the element, whereas the stainless steel properties are due to the metallic form.
Research into the cancer-preventing abilities of selenium is ongoing, as the exact right amount may decrease risk, but any more than that can greatly increase cancer occurrence. The only certain thing about selenium is that it plays an important role for human life, but can also easily prove a detriment.