What nutrients does your body need? You might think of vitamin C, vitamin D, calcium, iron – but lithium probably won’t cross your mind.
The element is better known for its use in batteries and as a treatment for bipolar disorder, but it is also found in drinking water and plants, such as cabbage, potatoes and whole grains.
This unassuming mineral might not be common knowledge, but a new study – recently published in Nature – has suggested it might play an important role in our brain health.
Lithium may even help protect us from developing dementia.
Lithium in the brain
Over a period of 10 years, scientists investigated how metals in the brain relate to Alzheimer’s disease, the most common form of dementia.
The research – led by Dr Bruce Yankner, professor of genetics and neurology at Harvard Medical School – involved assessing the concentration levels of 27 different metals in post-mortem brains.
These brains came from healthy individuals, as well as those who had developed mild cognitive impairment and some with Alzheimer’s.
The team examined the prefrontal cortex, a region involved with executive function and often affected in Alzheimer’s – as well as other regions.
In the prefrontal cortices of people with cognitive impairment or dementia, the scientists found significantly reduced levels of lithium.
But they didn’t find any major correlations between cognition and other metals across the brain samples.
Having found a link between lithium and brain health, the scientists then tested it out using mice which had been bred to have Alzheimer’s-like brain symptoms.
This time, they discovered that lithium could bind to amyloid beta – a protein which can contribute to the early stages of dementia, if it binds together – in the mice.
Some mice were given lower lithium levels than others throughout their lives, and they developed accelerated Alzheimer’s-like brain changes.
Meanwhile, the brains of mice with normal levels of lithium were better protected from the symptoms.
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What this means for humans
The study may have found a promising effect in mice, but could taking lithium do the same for human brains?
Unfortunately, avoiding dementia isn’t as simple as taking a lithium supplement.
Yankner’s research found that, when the human brain has Alzheimer’s disease, amyloid binds to prescribed types of lithium – that is, lithium carbonate, used to treat bipolar disorder – as well as lithium we naturally have in the body.
That means amyloid deposits might trap lithium, so there is less of the mineral available for the brain cells, accelerating memory-loss symptoms.
This could help explain why lithium levels appear lower in brains affected by Alzheimer’s.
Dr Lisa Barnes, cognitive neuropsychologist and professor of gerontology and geriatric medicine at Rush University Medical Center, wasn’t involved in this study, but has worked on her fair share of similar research.
She says that, while animal work has suggested lithium can slow disease progression, she isn’t convinced just yet.
“A recent clinical trial published in JAMA Neurology did not find evidence that participants with mild cognitive impairment who received a form of lithium [lithium carbonate] for two years improved on thinking or memory tests and MRI metrics did not change either.”
This trial was small and the dose was not as high as what has been used in clinical doses for other diseases, she adds, so it's not clear whether lithium would improve cognition.
“More research is needed,” Barnes adds.
Yankner’s team found the most success when the mice were given a different kind of lithium: lithium orotate. That’s because the amyloid didn't bind to the lithium this time, and Alzheimer’s-like symptoms were reduced.
This research could open up avenues for future research into Alzheimer’s prevention and treatment, using lithium orotate in particular.
However, these positive effects were still found in mice, so more work is needed on humans to understand what might be both safe and beneficial.
What to eat to protect your brain
Lithium has not yet been proven to protect the human brain from dementia – and, adds Yankner, it’s not officially recognised as an essential mineral in the US or UK.
But, while the jury is still out on lithium, which nutrients should we focus on for brain health?
Yankner says: “A well-balanced and healthy diet, particularly modelled on the Mediterranean diet, is probably the best way at present to maintain a nutritional status that protects against cognitive decline.”
The Mediterranean diet focuses on whole, plant-based foods, with healthy fats such as extra virgin olive oil and fish, and limits processed foods.
Barnes also notes that her research into nutrition was the basis for the MIND diet – or the Mediterranean-DASH Intervention for Neurodegenerative Delay diet, to give it its full name.
This is a combination of the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet.
It promotes the consumption of leafy green vegetables, olive oil, nuts, carrots, sweet potatoes and beans – foods that provide us with vitamins E and K, folate, and anti-inflammatory plant chemicals such as carotenoids and polyphenols.
Barnes says these “have all been shown to be protective for brain health.”
We should also be mindful of nutrient deficiencies, which can be surprisingly common in UK and US populations.
Yankner says that vitamin D deficiency is well-documented, especially among ageing populations living in northern climates.
This nutrient is important for keeping bones, teeth and muscles healthy, and it doesn’t tend to be a problem during summer months, when the body can create a healthy supply of vitamin D from sunlight.
But deficiencies often develop during the dark winter months – and, over time, could contribute towards cognitive decline.
For this reason, the NHS recommends UK citizens take a vitamin D supplement in winter to avoid deficiency.
“There is evidence that raising vitamin D levels in this ageing population might reduce cognitive decline and prevent dementia,” Yankner says.
He adds that vitamin B12 deficiencies can also be common among older generations.
“In individuals with low B12, supplementation can significantly improve cognitive function and mood, and in some cases reverse neurological deficits such as reduced sensation in the arms and legs.”
If you’re concerned about your own nutrition, Yankner says: “There is evidence that supplementation with a multivitamin may reduce the rate of cognitive decline during ageing.”
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