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.

People with Alzheimer’s disease have lower levels of lithium in their brains than those without cognitive impairment, and the metal appears to accelerate the accumulation of amyloid plaques and memory