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.

This suggests being consistent with the MIND diet may reduce the risk of HS, dementia and Alzheimer's disease, the authors said. Foods in this diet typically include whole grains, nuts, legumes, berries, vegetables (especially leafy greens), olive oil, poultry and fish.