A recent study published in Nature by Harvard researchers has found that lithium, a naturally occurring element in the brain, plays a crucial role in maintaining healthy brain function and may be key in both causing and treating Alzheimer's disease. The research indicates that people with Alzheimer's have lower lithium levels in their brains compared to those without cognitive impairment. Lithium deficiency appears to accelerate the accumulation of amyloid plaques and memory loss. Experiments with mice deprived of lithium showed impaired learning and nearly 2.5 times more amyloid plaques than those on a standard diet. Conversely, replenishing lithium levels with a novel lithium salt reversed memory loss and protected against cognitive decline in these animal models. The findings suggest that low-dose lithium supplementation could offer a safe therapeutic route for prevention and treatment of Alzheimer's. The study also highlights that amyloid plaques may trap lithium, causing its deficiency and neuronal damage. This research has reignited scientific interest in lithium's potential as a treatment, despite previous funding cuts to related projects. Additional studies, including a 2017 Danish investigation linking lithium levels in drinking water to dementia rates, support the element's protective role. Experts note that lithium orotate at doses far lower than lithium carbonate might be effective in humans. The discovery offers new hope for addressing Alzheimer's, which accounts for 60–80% of dementia cases and affects a significant portion of the aging population.