New Research Explores Lithium’s Role in Alzheimer’s Disease

A study from Harvard Medical School is investigating whether lithium, an element commonly known for its various uses, could be crucial in the development of Alzheimer’s disease.

Led by Dr. Bruce Yankner, a genetics and neurology professor, this nearly ten-year study claims to be the first to identify lithium naturally present in small amounts in the brain. It also suggests that this element might play a significant role in preventing cognitive decline.

The research, published in Nature, found a connection between low lithium levels in the brain and an increased presence of amyloid plaques and tau tangles, which are known contributors to Alzheimer’s. Trials conducted on mice showed that a lithium compound, lithium orotate, was able to reverse the disease, protect brain cells, and even restore some memory loss.

Experts caution that it’s too early to recommend lithium as a treatment for Alzheimer’s. They emphasize that further randomized controlled trials on humans are necessary. If the findings hold, measuring lithium levels might aid in early detection and enhance our understanding of aging brains.

Dr. Yankner expressed hope that lithium could not only slow down cognitive decline but also restore functionality, as it seemed to do in advanced mouse models. However, he noted that judgment should be reserved until human trials are conducted.

Understanding Lithium

Lithium is a naturally occurring element in the same family as sodium and potassium. It’s soft and silvery and is utilized in fields ranging from nuclear energy to battery production. Interestingly, it has also been used as a mood stabilizer for those with bipolar disorder since the 1900s. Some might remember that 7 Up contained lithium citrate until it was banned due to health risks associated with overconsumption.

Previous research has hinted at lithium’s potential link to dementia and Alzheimer’s disease. A 2017 Danish study suggested that areas with trace amounts of lithium in drinking water had lower rates of dementia, implying that even slight, prolonged exposure could significantly impact cognitive health.

Findings from the Recent Study

This latest study utilized brain tissue samples from the RUSH Memory and Aging Project, involving thousands of participants at various cognitive levels. Using advanced tools to detect minute amounts of metals in the brain, the team discovered that individuals with mild impairment or advanced Alzheimer’s had lower lithium levels compared to their cognitively healthy counterparts.

Yankner noted that lithium levels were among the first to drop in donors showing early signs of memory loss. When researchers limited lithium intake in mice—both healthy and those with Alzheimer’s traits—they observed accelerated cognitive decline and memory loss, as well as quicker formation of amyloid plaques in the Alzheimer’s group.

Yankner’s team found that lithium becomes depleted when amyloid plaques attach to it, which decreases lithium’s availability for essential brain functions, like those performed by microglia that clear away harmful plaques. In lithium-deficient conditions, these microglia struggled to do their job.