Amyloid plaques trap lithium
Yankner’s team tested mice by severely reducing lithium in their diets. It’s found in some foods and in water that flows through lithium-rich rock. The mice with less lithium had worse memory.
When they took mice that were engineered to have genes that gave them Alzheimer’s symptoms and gave them a low lithium diet, “the pathology dramatically increased,” Yankner explains. The mice were also less able to clear amyloid plaques, he says.
As amyloid plaques start to accumulate in the brain, they trap lithium as the disease progresses, Yankner explains.
So then his team tested two types of lithium in those mice and learned that the type of lithium mattered.
Lithium carbonate, used for bipolar disorder, got snared by the plaques. Lithium orotate was less likely to get grabbed, and it restored the memory of the mice.
More work needed in humans
Results in mice can be encouraging, but scientists need to do more studies on humans, says Manisha Parulekar, M.D., codirector of the Center for Memory Loss and Brain Health at the Hackensack Meridian Neuroscience Institute at Hackensack University Medical Center, who wasn’t involved with the study but reviewed the report. Any treatments must be shown to be effective and safe in large studies of people before they can be recommended.
Lithium orotate is available on the market as a supplement, but lithium can be toxic to humans at certain levels, so no one should take it without a doctor’s care, Parulekar says. Patients taking lithium for bipolar disorder should have their blood levels checked regularly, she adds.
Because memory was reversed in mice but has not been proved to reverse in humans, Yankner says people should not take lithium supplements. “You can never be sure what’s in them,” Yankner says, noting that they’re not regulated by the Food and Drug Administration.
“We need to wait for the clinical trials to really know what is the best dose for a person and to be assured that there won’t be toxicity,” Yankner adds.
The big takeaway from the study was confirming the effects of lithium depletion in the brain, seeing how it affected plaques and seeing that lithium orotate has the potential to reverse damage, Parulekar says. “I think that’s the reason why this is getting so much buzz,” she adds.