By Daily Mail (U.S.) | Created at 2026-08-08 15:12:03 | Updated at 2026-08-08 15:18:52
8 minutes ago
More than seven million Americans have dementia, a number that is projected to almost double by 2030.
But now, some researchers say you may be able to reduce your risk by ensuring to get enough of a cheap and frequently overlooked vitamin.
Magnesium is vital for all of life's processes, from keeping our hearts beating to helping our muscles move.
It also holds vital importance for neurological health by calming overactive brain signals, protecting the blood-brain barrier and dampening the inflammation that drives cognitive decline.
But the body cannot produce magnesium on its own, meaning it must come from foods like leafy greens, nuts and seeds.
An estimated 60 percent of Americans fail to get enough magnesium in their diets, and nearly half are deficient without knowing it. The signs, fatigue, muscle cramps, trouble sleeping and anxiety, are subtle and easily dismissed.
Along with food, research on magnesium supplementation has produced promising results for brain health. For cognitive function, higher magnesium intake is associated with larger brain volume and a lower risk of cognitive impairment, though experts caution that the evidence remains mixed.
And at just 35 cents per pill, experts believe it's a cheap option when food alone cannot meet someone's needs.
Sixty percent of Americans are magnesium-deficient and most are not aware
'Magnesium is extremely important for brain function,' Dr David Watson, a neuropsychologist and CEO of the Alzheimer's Research Treatment Center, told the Daily Mail.
It's also well-known to boost sleep, as studies have found that magnesium bisglycinate modestly improves insomnia symptoms, while magnesium L-threonate has been linked to both better sleep quality and a reduction in estimated brain age.
Different forms of magnesium are used for specific purposes. Magnesium glycinate is highly absorbable and gentle on the stomach, often used for sleep and relaxation support due to the calming amino acid glycine.
Magnesium citrate is also well-absorbed but can have a laxative effect, making it better for constipation relief.
Magnesium threonate may cross the blood-brain barrier more effectively and is marketed for brain health. Magnesium oxide, on the other hand, is poorly absorbed and primarily used for constipation.
What exactly makes this humble mineral so critical for brain health? The answer lies in magnesium's role as a natural gatekeeper in the nervous system.
'It’s required for nerve signaling, cellular energy production, muscle relaxation, and healthy sleep rhythms,' Dr Micah Craig, a board-certified internal medicine physician, told the Daily Mail.
Magnesium acts as a natural calcium blocker in the brain. It regulates the flow of calcium through channels on the surface of brain cells – tiny gateways that control when calcium enters the cell.
Magnesium may boost brain health and lower dementia risk, but experts note mixed evidence
By keeping calcium in check, magnesium prevents brain cells from becoming overstimulated, a process that can otherwise lead to cell damage and death.
Magnesium also blocks the N-methyl-D-aspartate (NMDA) receptor, a key player in learning and memory.
At normal resting membrane potential, magnesium sits inside the receptor like a cork in a bottle, preventing excessive calcium from flooding in.
When magnesium levels drop, that cork is removed and the resulting overactivation of NMDA receptors can trigger excitotoxicity, a destructive cascade that kills neurons.
This protective mechanism is particularly relevant for Alzheimer's disease.
Authors of a 2022 review noted that magnesium deficiency contributes to the buildup of amyloid-beta plaques, the hallmark of Alzheimer's, by shifting the brain's processing of the amyloid precursor protein toward the harmful pathway.
At the same time, low magnesium promotes the phosphorylation of tau protein, which forms the toxic tangles seen in Alzheimer's brains.
In animal studies, magnesium curbed brain inflammation, prevented amyloid plaques, and improved learning and memory by reducing inflammatory signals, blocking the formation of amyloid and aiding its clearance.
Mineral content in common vegetables including cabbage, lettuce, tomatoes and spinach has dropped 80 to 90 percent since 1914, with magnesium losses mirroring calcium and iron
The protective effects were striking. Magnesium reduced inflammation in the brain, helped clear the protein clumps linked to Alzheimer's and preserved the blood-brain barrier – the brain's natural defense against toxins and germs.
At the same time, magnesium increases brain-derived neurotrophic factor (BDNF), a protein that supports the survival of dopamine-producing neurons, the very cells that degenerate in Parkinson's, causing the tremors and movement problems patients with the neurodegenerative disease experience.
The mineral also reduces the formation of alpha-synuclein, the toxic protein that clumps together in Parkinson's-affected brains.
These clumps, known as Lewy bodies, are believed to damage and kill dopamine-producing neurons, driving the movement symptoms and cognitive decline seen in the disease.
A multicenter case-control study in Japan found that higher magnesium intake was associated with a reduced risk of Parkinson's disease.
Parkinson's patients also tend to have lower magnesium levels in their cerebrospinal fluid than healthy people. And in animal studies, a chronic lack of magnesium – passed down and maintained over multiple generations – has been shown to damage mitochondria and kill off the very neurons that produce dopamine.
The common thread across all these conditions is neuroinflammation.
Magnesium deficiency fuels this fire. When magnesium levels drop, the brain's immune cells, called microglia, become hyperactive and pump out inflammatory cytokines like TNF-alpha and interleukin-6.
Magnesium is found in leafy greens, nuts, seeds, beans and whole grains, but modern diets heavy in processed foods often fall short.
These inflammatory molecules create a self-sustaining loop, perpetuating the damage that characterizes Alzheimer's, Parkinson’s and multiple sclerosis.
Magnesium, by contrast, tamps down this response. In laboratory studies, magnesium inhibited the activation of NF-kappaB, the master regulator of inflammation, and reduced the production of inflammatory mediators.
Evidence showing the benefits of taking magnesium supplements is promising.
A 2026 randomized controlled trial found that six weeks of magnesium L-threonate improved overall cognitive performance, working memory and reaction time in adults with sleep issues, with an estimated 7.5-year reduction in brain cognitive age.
Participants self-reported less sleep-related impairment, such as feeling tired during the day, though there were no significant differences between the magnesium and placebo groups on other sleep measures, including self-reported sleep disturbances, restorative sleep or data from wearable sleep-tracking rings
The study had limitations. It only lasted six weeks, and improvements were seen in a group with pre-existing sleep complaints.
Some observational data is encouraging. One UK Biobank study of nearly 6,000 people found higher dietary magnesium intake was associated with larger brain volumes, and this effect was partially explained by lower inflammation.
Still, observational studies cannot prove that magnesium supplements directly protect the brain, and most clinical trials have been small or short-term.
Magnesium supports sleep by calming the nervous system and promoting relaxation, with magnesium glycinate being one of the most well-studied forms for sleep
As for sleep, in one 2024 study, adults who took magnesium L-threonate for three weeks said they slept more deeply, felt more energetic and woke up in better moods. But researchers cautioned that those were subjective reports, not hard measurements.
Experts told the Daily Mail that most Americans would benefit from more magnesium in their diets.
Health authorities recommend 310 to 420 milligrams of magnesium per day for adults, depending on age and sex. Men should aim for 400 to 420 mg, while women need 310 to 320 mg.
Pregnant and breastfeeding women require slightly more because their bodies are supporting fetal growth and milk production, increasing overall demand for the mineral.
Despite these guidelines, over half of Americans don't consume enough magnesium through diet alone – and 45 to 50 percent are estimated to be truly deficient, with depleted body stores that can affect health.
'Magnesium deficiency is extremely common, especially since produce nowadays has less magnesium in it due to depleted soils,' Watson said. 'Stress, caffeine and alcohol also deplete magnesium levels.'
'What’s more frustrating,' plastic surgeon Dr James Chao, who often counsels his post-op patients on nutrition, added, 'is that your standard blood panel won’t necessarily pick it up.'
Only about 1 percent of the body's magnesium supply circulates in the blood. The rest is stored in bones, while the kidneys can slash urinary losses from 120 mg a day to almost nothing when levels run low.
'As a result, your tissue stores can become depleted while your doctor’s fancy interoffice document delivery service sends you a report back that says everything’s normal,' he said.
Experts generally recommend a food-first approach. One benefit of getting magnesium from food is that there's no upper limit; your kidneys simply excrete any excess.
'Modern foods tend to be overly processed – which often involves stripping magnesium – and not enough beans, nuts, seeds and leafy greens,' Craig said.
Some of the best sources of magnesium include dark leafy greens like spinach, nuts and seeds such as almonds and pumpkin seeds, legumes like black beans and whole grains. Fish such as salmon and halibut, as well as avocados, bananas, dark chocolate and yogurt, are also excellent choices.
If you do consider supplements, start with a small dose and take it at night, as magnesium can cause drowsiness and aid sleep, according to the Cleveland Clinic.
The traditional upper limit for supplemental magnesium is 350 mg daily, though a recent review by the Council for Responsible Nutrition, a supplement industry trade group, raised that to 500 mg for healthy adults.
Higher doses can cause diarrhea, nausea and cramping.
'[Magnesium supplementation] is best indicated for individuals with an inadequate dietary magnesium intake, those with documented magnesium deficiency, those who are at higher risk due to medications or GI issues and for those who have documented GI dysfunction,' Craig said.
Before supplementing, talk to your doctor, especially if you have kidney or heart conditions, or take medications like antibiotics, diuretics or osteoporosis drugs, as magnesium can interact with them.
