Researchers at Harvard Medical School have stumbled upon a potential new player in the development of Alzheimer’s disease, which is low lithium levels in the brain. Lithium, a metal known for balancing mood-regulating chemicals and protecting neurons, has long been used to treat conditions like bipolar disorder and depression. Some intriguing new findings suggest that lithium might be a “missing link” in understanding Alzheimer’s risk, as mentioned in a Harvard press release.
The study involved testing lithium’s effects on mice, as well as examining human brain tissue and blood samples. In mice models of Alzheimer’s, a lack of lithium significantly increased amyloid beta deposits, a key marker of the disease, compared to mice with normal lithium levels. This pattern was mirrored with the Alzheimer’s-related protein tau, highlighting lithium’s potential protective role.
The human brain samples for this study were sourced from the Rush Memory and Aging Project in Chicago, which maintains a vast collection of post-mortem brain tissue. These samples spanned the full range of cognitive health, from no signs of disease to advanced Alzheimer’s. The research found that as Alzheimer’s symptoms worsened, lithium levels in the brain became “greatly diminished,” offering a new perspective on the disease’s progression.
The study broke new ground by demonstrating that lithium exists naturally at biologically meaningful levels without being administered as a medication. As amyloid plaques build up in the brain, they bind to lithium, preventing it from performing its protective functions. When mice were fed a diet low in lithium, they experienced accelerated aging, memory loss, and cognitive decline, mirroring Alzheimer’s effects.
Interestingly, the researchers identified a new lithium compound, lithium orotate, that did not bind to amyloid. Mice that consumed this compound showed improvements in memory and a reversal of brain damage, even in advanced stages of the disease. These promising findings were published in the journal Nature, capturing the scientific community’s attention.
Professor Bruce Yankner, the study’s senior author, expressed his fascination with lithium’s widespread impact on Alzheimer’s symptoms, noting he had not observed anything similar in his extensive experience with the disease. While the study’s results are promising, they come with limitations. As Ozama Ismail, Ph.D., from the Alzheimer’s Association, pointed out, mouse models, although critical, do not directly replicate human Alzheimer’s, and further research is necessary.
Ismail emphasized that understanding lithium’s therapeutic potential for Alzheimer’s will require large-scale clinical trials in human populations. If these future studies confirm the findings, routine blood tests might be used to screen for lithium levels and identify those at risk. Researchers agree that more investigation in human clinical trials is crucial.
Yankner cautioned against people self-administering lithium compounds, stressing the need for controlled human clinical trials to validate the results seen in mice. The hope is that lithium might offer more than just anti-amyloid or anti-tau therapies, potentially reversing cognitive decline and improving patients’ lives. The study received backing from several organizations, including the National Institutes of Health and the Aging Mind Foundation.
