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.

A new study led by Harvard Medical School researchers found that lithium can help the brain resist the ravages of aging and als. Lithium is a metal found in some foods, drinking water, and in trace amounts in our bodies.

Researchers at Harvard Medical School in Boston now say that lithium could help treat the 7 million people with Alzheimer's disease.