In a potentially groundbreaking finding, a new study in mice suggests that the metal lithium, long used as a mood stabilizer, may play a crucial role in maintaining brain health and could offer a protective effect against Alzheimer’s disease. The research, conducted by scientists at Harvard Medical School and Rush University and reported by CNN, suggests that lithium is a naturally occurring, essential element in the body.

The study, published in the journal Nature, found that depleting lithium from the diet of mice led to brain inflammation and changes associated with accelerated aging. In mice bred to develop Alzheimer's-like symptoms, a low-lithium diet sped up the formation of the hallmark plaques and tangles, as well as memory loss. Conversely, maintaining normal lithium levels protected the mice from these changes.

A New "Unifying Theory" for Alzheimer's

According to Dr. Bruce Yankner, a professor of genetics at Harvard Medical School who led the study, this research provides a "unifying theory" that could help explain the complex mechanisms behind Alzheimer's. The study proposes that as the sticky beta amyloid plaques build up in the brain, they bind to lithium, effectively depleting it from the surrounding cells. This, in turn, impairs the function of microglia, the brain's "waste managers" responsible for clearing away these plaques. This creates a vicious cycle where a lack of lithium allows more plaques to accumulate, further soaking up available lithium.

The researchers also found that a specific compound, lithium orotate, which does not bind to amyloid beta, reversed these brain changes in mice with signs of Alzheimer’s. The treated mice showed a reduction in plaques and tangles and regained their ability to perform tasks requiring memory.

Important Caution: Don't "Try This at Home."

While the findings are promising, experts are urging caution. Dr. Yankner stressed, "A mouse is not a human. Nobody should take anything based just on mouse studies." The doses of lithium used in the study were about 1,000 times lower than those prescribed for bipolar disorder, which can have side effects like thyroid or kidney toxicity. The next step will be to replicate these results in human trials to determine the proper dose and safety.

This research builds on previous studies that hinted at lithium's protective role, including a 2017 Danish study that found people with higher levels of lithium in their drinking water were less likely to be diagnosed with dementia. Foods rich in lithium, such as leafy green vegetables, nuts, and legumes, are often already recommended for a healthy diet, suggesting that some of the foods that are good for brain health may be beneficial due to their lithium content.