A new Harvard study is offering cautious optimism in the search for treatments against Alzheimer’s disease, the most common cause of dementia worldwide.
Published in Nature, the research found that patients with Alzheimer’s or mild cognitive impairment—a precursor to dementia—had significantly reduced lithium levels in their brains.
Lithium, best known today as a component of rechargeable batteries, has also been used for decades as a medication for bipolar disorder. Earlier in history, it even appeared in mood-enhancing tonics and soft drinks, including the original formula of “7 Up.”
The Harvard team’s experiments on mice genetically modified to display Alzheimer’s symptoms showed striking results: a specific compound called lithium orotate not only slowed the build-up of amyloid plaques—protein deposits linked to the disease—but also appeared to reverse memory loss in animals already showing cognitive decline.
By contrast, the lithium carbonate typically prescribed for bipolar disorder bound too quickly to amyloid plaques, which may explain why previous clinical trials in humans produced mixed results.
The researchers suggest a vicious cycle may exist: reduced lithium leads to more amyloid plaques, which in turn trap even more lithium, further depriving the brain.
While the findings are promising, experts stress that human trials are still needed. These will likely take years and face funding challenges, since lithium cannot be patented as a drug. Independent specialists noted that public funding will probably be essential for advancing the research.
For now, the study adds weight to past observations showing lower dementia rates in regions where drinking water naturally contains higher lithium levels—and opens a new avenue of hope in the long fight against Alzheimer’s.
