There are some elements that we know are required for life: Carbon, oxygen, hydrogen, nitrogen, phosphorus. Others are critical side players: Iron, calcium, potassium and sodium. For a long time, lithium seemed like it was in a third category of elements—like titanium or radium—better left outside the body unless something has gone wrong.
Lithium powers batteries and many of our other technologies, and at the same time, doctors have prescribed it for years as an effective treatment for bipolar disorder and some kinds of major depression. But “up until recently, we did not think about lithium as something that’s physiologically necessary,” says Tomas Hajek, a psychiatrist at Dalhousie University in Nova Scotia.
Now, studies are suggesting that low doses of the element might halt—and even reverse—the ravages of Alzheimer’s disease and cognitive decline. While scientists are still trying to understand how lithium exerts its effects, they are coming to realize that the metal might join the list of key elements our bodies—and especially our brains—need to thrive.
The lithium lift
After lithium’s discovery in 1817, scientists began to investigate the light, silvery metal as a treatment for mental illnesses like “general nervousness.” In the early 20th century, lithium products began to pop up, literally. An early recipe for 7-Up contained lithium, and it’s one explanation for the soda’s name (another is the original number of ingredients in the drink). “The ‘up’ was presumably the psychological effects of lithium, and the seven was the molecular weight,” says Bruce Yankner, a neuroscientist at Harvard Medical School in Boston. As with many patent medicines and tonics during this era, the doses were high, the effects were toxic, and 7-Up now contains no “up” with a molecular weight of seven.