A recent study published in *Nature* suggests that restoring the brain’s natural lithium levels could help protect against, and potentially reverse, Alzheimer’s disease. The research indicates a notable connection: as lithium concentrations drop, memory loss and Alzheimer’s-related symptoms, like amyloid plaques and tau tangles, tend to emerge. In mouse models, a specific lithium supplement showed promise in reversing memory loss and improving brain health.
Ashley Bush, a neuroscientist at the University of Melbourne, called the findings groundbreaking, especially since current Alzheimer’s medications primarily focus on amyloid plaques. “This approach addresses the key issues associated with the disease,” she noted.
If these results are confirmed in human trials, the impact could be significant. With over 55 million people globally affected by dementia—most of which are Alzheimer’s cases—the potential for a new treatment is definitely crucial. Current therapies slow cognitive decline but don’t restore function, said Bruce Yankner, a geneticist at Harvard Medical School. “We don’t yet have the penicillin for Alzheimer’s,” he remarked.
Old remedy, new insights
Lithium was once popular in the 19th and early 20th centuries as a health tonic, and re-emerged as a leading treatment for bipolar disorder in the 1970s. Interestingly, it was observed that brain aging slowed in people with bipolar disorder who took lithium. Studies also found a correlation between areas with lithium in the water and lower dementia rates, but trials examining lithium’s impact on cognitive decline have yielded mixed results.
In an effort to clarify lithium’s role, Yankner and his team discovered that lithium is naturally present in the brain and is vital for its function. They noted that lithium levels in regions impacted by Alzheimer’s are lower than in healthy areas. Moreover, in individuals suffering from mild cognitive impairment—often a precursor to Alzheimer’s—lithium seems to get bound up in amyloid plaques, reducing its availability for important brain processes.
Further research showed that mice with low lithium levels developed more amyloid plaques, creating a damaging feedback loop wherein declining lithium leads to increased amyloid, which then results in even less lithium. The researchers also connected the loss of lithium with other Alzheimer markers, such as tau protein tangles.
The usual form of lithium tested in trials has been lithium carbonate, but the team found that this form is easily trapped by amyloid plaques. In contrast, lithium orotate appears to escape this issue. When they administered low doses of lithium orotate to mice, it counteracted brain damage linked to Alzheimer’s and improved memory. The limited benefits of lithium carbonate in prior studies might illustrate the inconsistencies found in earlier research.
