David Bridges
Alzheimer’s disease stands as one of the most devastating conditions that individuals can confront. Despite the remarkable progress in medical science, options for intervention become limited once the symptoms of this debilitating disease manifest. Recent research published this week may illuminate a significant and previously overlooked factor that contributes to the progression of Alzheimer’s, potentially paving the way for innovative treatments.
Conducted by scientists at Harvard Medical School, this groundbreaking study was published on Wednesday in Nature. The researchers delved into human brain samples and utilized mice models to uncover evidence that our brains inherently contain the element lithium. Notably, a deficiency of this vital element could elucidate some of the damage caused by Alzheimer’s disease. An outside expert corroborated the validity of these findings, suggesting they may have unveiled a crucial aspect of this complex neurological disorder, as reported by Gizmodo.
Timothy Chang, a neurologist at the University of California, Los Angeles, who was not directly involved in the study, praised the research team for conducting comprehensive and meticulously designed studies. He noted that they effectively investigated the association between low levels of lithium and Alzheimer’s disease across diagnostic, protein, cellular, and gene levels. Chang also serves as the director of the California Alzheimer’s Disease Center at UCLA.
The brains of individuals affected by Alzheimer’s disease exhibit numerous distinctive characteristics when compared to those of cognitively healthy individuals. A notable feature is the elevated levels of misfolded amyloid beta and tau proteins, which are typically essential for various brain functions. However, these are not the sole alterations observed in patients with Alzheimer’s. During their investigation into these other changes, the researchers at Harvard made a significant discovery.
Utilizing existing projects that had gathered postmortem tissue samples, the researchers compared the concentrations of approximately 30 different metals in the brains of individuals who had died at various stages of cognitive health. Their findings revealed a striking difference in lithium levels: individuals with healthy cognitive function displayed relatively high concentrations of this element, while those with Alzheimer’s disease had markedly lower levels. Importantly, this deficiency was evident even in individuals who exhibited only mild memory issues prior to their passing.
Further investigations involved both healthy mice and genetically modified mice that are predisposed to developing a variant of Alzheimer’s disease. The researchers observed that depleting lithium from these mice appeared to hasten the accumulation of harmful amyloid beta and tau in their brains, resulting in noticeable memory decline. They also discovered that this depletion is likely caused by amyloid beta plaques binding to the brain’s lithium, which adversely affects all major brain cell types.
Although previous studies have hinted at a potential link between lithium and Alzheimer’s disease, the authors of this new research assert that theirs is the first to conclusively demonstrate that our brains naturally contain this element. Moreover, the findings suggest that lithium is crucial for maintaining optimal brain health, and its absence may play a significant role in the onset of Alzheimer’s disease.
“This is the first study to propose that a deficiency in lithium could contribute to Alzheimer’s disease,” stated Bruce Yankner, the senior author and a professor of genetics and neurology at the Blavatnik Institute of Harvard Medical School. He emphasized that prior to this study, lithium was not considered a natural substance in the brain with biological implications; it was merely viewed as a drug with pharmacological effects at higher doses. This research marks a pioneering effort to explore the consequences of lithium deficiency within the brain.
The implications of this study, while still in the early stages, could be profound. Yankner and his research team successfully identified a lithium-based compound that is not easily bound by amyloid beta. When this compound was administered to older healthy mice and mice with Alzheimer’s, it appeared to avert the detrimental brain changes and memory loss that typically accompany this neurodegenerative condition. In contrast, even the most effective treatments currently available for Alzheimer’s, which target amyloid beta, only modestly delay the disease’s progression.
Other forms of lithium are already employed in medicine for treating certain mental health conditions, particularly depression. However, these alternatives necessitate high dosages to achieve therapeutic effects and often result in numerous side effects. In contrast, the compound developed by the research team only required a significantly lower dose to exhibit effectiveness in mice, with no observed toxicity whatsoever.
“Further clinical studies involving human participants would be essential to determine whether the appropriate type and dosage of lithium can prevent or slow the progression of Alzheimer’s disease,” Chang remarked.
Yankner and his team are now advancing their research efforts to ensure that their lithium-based compound (or a similar variant) can undergo safe testing in human clinical trials. Even prior to that, the discovery could lead to significant advancements in other areas. For instance, it may become feasible to assess individuals’ risk of developing Alzheimer’s disease by measuring their lithium levels. Additionally, many mysteries regarding lithium and its role in brain health remain to be unraveled.
“As a neuroscientist, I am eager to delve deeper into the physiological roles of lithium in the brain,” Yankner expressed. “I believe we have only begun to scratch the surface of what promises to be a fascinating area of biological research.”
Brandon Fletcher
Daniel Mercer
