In a major new finding almost a decade in the making, researchers at Harvard Medical School say they’ve found a key that may unlock many of the mysteries of Alzheimer’s disease and brain aging — the humble metal lithium.

In a provocative new study, Harvard Medical School scientists found that lithium, an element found in some foods and drinking water and in trace amounts in our bodies, can confer resistance to brain aging and Alzheimer’s.

Years of investigation by scientists at Harvard has revealed that lithium is deeply involved in Alzheimer’s disease, a finding that could lead to new treatments.