Mention lithium and you likely conjure up an image of lithium batteries or a medication to treat bipolar disease. But researchers are now looking at another aspect of lithium. The possibility that lithium in the diet may play a role in reducing the risk of Alzheimer’s disease. This is not the first time that intake of lithium has been linked with medicinal effects. Soon after the element was discovered in 1817 in the mineral petalite by Swedish chemist Johan August Arfvedson, its salts as well as water that naturally contained lithium salts, were promoted for the treatment of gout with the mistaken belief that lithium was capable of removing uric acid from the body.
In the late 1800s, “Buffalo Lithia Water” was advertised as a rejuvenating tonic, and even the original Coca-Cola syrup contained lithium citrate. So did “Lithiated Lemon-Lime Soda” eventually renamed as 7-Up, originally marketed as a hangover remedy and mood booster. In the 1940s, lithium chloride was marketed as a low-sodium substitute for salt for people with high blood pressure with disastrous results. The high dose of lithium resulted in kidney problems including some fatalities. This resulted in skepticism when Dr. John Cade claimed in 1949 that lithium carbonate was an appropriate treatment for bipolar disease. That skepticism faded when trials proved its efficacy, although there is a need to monitor for kidney and thyroid problems in patients taking lithium carbonate.
Now for the Alzheimer’s connection. A study in 2022 found that patients treated with lithium for bipolar disease had about half the risk of developing Alzheimer’s disease compared with people not receiving such treatment. Another study showed a decreased risk of dementia in people drinking water with a higher lithium content. Now a Harvard University study found a reduced level of lithium in the prefrontal cortex of Alzheimer’s patients. That’s the part of the brain crucial for memory and decision making. By contrast, the researchers led by Harvard neuroscientist Bruce Yankner found a higher level of lithium in the amyloid plaques that characterize Alzheimer’s disease. This was a post-mortem study of the brains of participants in the “religious orders study,” a long-running medical study involving Catholic nuns, priests and brothers aged 65 year and older who had willed their brains for medical research.
It seemed that the lithium supply in the brain, which comes from lithium in the diet, mostly found in plant foods, was being reduced by being sucked into the amyloid plaques, leaving less lithium in the rest of the brain! To investigate this further, the lithium content of the diet was severely reduced in a species of mice prone to exhibit Alzheimer’s-like symptoms. After 8 months these mice performed significantly worse on memory tests than mice on the standard laboratory diet and also showed changes in the brain similar to that seen in Alzheimer’s patients.
A possible interpretation of the findings is that a low level of lithium in the brain is a risk factor for Alzheimer’s and that lithium supplements may be protective against the disease. The Harvard team investigated this possibility by treating mice with Alzheimer’s symptoms with lithium orotate, a compound they found was the least likely to be trapped in the amyloid deposits. After treatment for nine months, the mice showed significantly reduced plaques and performed as well as normal mice on memory tests.
Needless to say, mice are not men, and human clinical trials are needed to determine if dietary lithium supplements can help ward off Alzheimer’s disease. Since lithium orotate occurs naturally in the body, it qualifies to be sold as a dietary supplement. The dose in these supplements is hundreds of times smaller than that used to treat bipolar disease, so the risk of supplementation would appear to be small. But it is too early to jump on that bandwagon.
Click here to watch the .Ěý
