What the Recent Harvard Research Suggests

Alzheimer’s disease and other forms of dementia remain among the most challenging medical problems of our time. Despite decades of research, treatments that stop or reverse the disease are elusive. Now, a major new study from Harvard Medical School suggests that a simple trace element — lithium — might offer surprising insights into how dementia develops and how it might be treated or prevented.

What the Harvard Study Found

Published in Nature in 2025, Harvard researchers led by Dr. Bruce A. Yankner investigated the role of lithium — a lightweight metal found naturally in the brain and in trace amounts in foods and drinking water. The team discovered several remarkable things:

• Lithium naturally occurs in the human brain and appears essential for healthy brain function.

• People with Alzheimer’s or mild cognitive impairment had significantly lower lithium levels in key brain areas compared with those without memory problems.

• In mouse models of Alzheimer’s, removing lithium from the diet accelerated memory loss and the buildup of hallmark disease features like amyloid plaques and tau tangles.

• Replacing lithium — especially in a form that avoids being trapped by amyloid plaques — prevented and even reversed memory loss and brain pathology in mice.

The compound the researchers focused on is lithium orotate — an organic lithium salt that seems to evade binding with amyloid plaques better than other forms of lithium (like lithium carbonate). In mice, very low doses of lithium orotate restored synapses, reduced plaques and tangles, and brought memory performance back to levels seen in much younger animals.

Why This Matters

This work suggests a new way of thinking about Alzheimer’s:

• Instead of targeting just one aspect of the disease (like amyloid plaques or tau tangles), lithium might help support overall neuronal health, including synaptic connections, myelin integrity, and immune cell function.

• Lithium levels might one day be used as a biomarker — a way to identify people at higher risk before symptoms begin.

• The effective doses seen in mice were much lower than those used in psychiatric treatments, potentially offering benefits with fewer side-effect risks.

These findings build on earlier observations — such as epidemiological studies linking higher lithium in drinking water to lower rates of dementia — strengthening the idea that lithium plays a protective role in brain aging.

What This Doesn’t Mean — Yet

Despite the excitement, it’s important to be clear: human evidence is still very limited. The Harvard research, though groundbreaking, was conducted primarily in mice and in human brain tissue analyses. Clinical trials in people are needed to determine:

• Whether lithium orotate truly prevents or reverses dementia in humans.

• What doses are safe and effective in older adults.

• How it interacts with other medications and health conditions.

As the researchers themselves emphasize, you should not self-prescribe lithium orotate as a dementia treatment. Lithium — even in lower doses — can interact with thyroid function, kidneys, and other body systems if not monitored properly.

The Bottom Line

The Harvard study represents one of the most promising leads yet in dementia research and has opened a new therapeutic avenue worth serious exploration.

But for now, the research should be viewed as early and hopeful — not definitive. Researchers are calling for clinical trials to test whether these effects translate into real benefits for people at risk of or living with Alzheimer’s disease.

Of Interest

Functional medicine providers have been recommending lithium orotate for years. It is an over the counter supplement with a very low side effect profile. Research shows it is extremely well absorbed and enters the brain more efficiently than other forms of lithium. Though safe for most people, there are some caveats and you should consult an informed provider before starting any supplementation.

Stay tuned — this line of research could reshape how we understand and treat dementia in the years ahead. Want to know more about lithium orotate- check back in soon for a follow-up article on its dosing, risks and pharmocokinetics.