How Magnesium Supports Brain Health

What Is Magnesium?

Magnesium is a vital mineral involved in numerous physiological processes. Found predominantly within cells, magnesium is a cofactor for over 600 enzymes involved in all major cellular metabolic pathways, such as cell growth, DNA and protein production, and the generation of ATP, which is the molecule that provides energy to cells.¹ Many of the roles of magnesium in the body are crucial not only for our health but even for our survival: it is required for the contraction of cardiac muscle (i.e., heartbeat), skeletal muscle movement, immune responses, and neuronal activity.

Why Magnesium Matters for Brain Health

Magnesium’s role in the production of cellular energy as ATP is essential for health because, without ATP, cells simply wouldn’t function or survive. ATP is crucial for all tissues and organs of the body but it’s particularly important for the brain because of its high energy demands—it accounts for about 20% of the body’s daily energy expenditure.² Therefore, adequate magnesium levels are critical for the brain to perform optimally.

Magnesium is also needed for the synthesis of neurotransmitters such as dopamine and serotonin, it modulates the activity of receptors for the neurotransmitters glutamate and GABA, and it supports the levels of neural growth factors (neurotrophins) such as brain-derived neurotrophic factor (BDNF). These are processes that underpin learning, memory, mood regulation, sleep, and neuroplasticity, for example.^3–8 

Neuroprotection is another key function of magnesium. Magnesium helps protect neurons from toxicity induced by excessive calcium influx, strengthens the blood-brain barrier, regulates oxidative stress, and promotes neuronal survival, making it indispensable for long-term brain health.^1,8–10

Aging, Magnesium Deficiency, and Cognitive Health

Aging is associated with lower magnesium levels in the body.^11,12 This happens primarily because of three main factors: 1) insufficient dietary magnesium consumption, 2) a reduction in the intestinal absorption of magnesium, and 3) increased excretion of magnesium in urine due to poorer kidney function and renal reabsorption.^12,13 

Because of its vital functions, low magnesium levels can have a great impact on health as we age^11,12 and have been linked to all 12 Hallmarks of Aging.¹⁴ Reduced magnesium levels in the brain have also been linked to age-­associated neurological issues.¹⁵ Fortunately, clinical studies suggest diets rich in magnesium may support cognitive health as we age.^16,17 

Magnesium and Brain Volume

One of the aspects of brain aging that magnesium may help to delay is brain atrophy. As we age, gradual changes in gray and white matter result in brain volume loss, with profound impacts on cognitive health.^18–20 

A recent study²¹ explored the relationship between dietary magnesium intake from food and supplements and age-related changes in brain structure in 6,001 cognitively healthy adults aged 40 to 73. At the study's conclusion, after 16 months, MRI scans assessed the volumes of gray matter, white matter, and the hippocampus (a brain region involved in learning and memory, among other functions), as well as white matter lesions. Researchers then correlated these measurements with magnesium intake levels.

The study found that higher magnesium intake was associated with larger brain volumes, particularly in gray matter and the hippocampus, and fewer white matter lesions. Participants consuming over 550 mg/day of magnesium were better able to maintain brain volumes relative to those consuming 350 mg/day. Brain volume maintenance with the higher magnesium intake corresponded to about 1 year of typical aging for the study population. This suggested that increasing magnesium intake may help sustain brain health and delay the brain atrophy that often accompanies age, which in turn may help to maintain cognitive health.²¹

Interestingly, postmenopausal women appeared to derive slightly more benefit from higher magnesium levels than men or premenopausal women, though the reasons for this are not yet fully understood.²¹

These findings highlight magnesium's importance in maintaining brain health and cognitive function throughout life, particularly as we age. Even in early middle age, higher magnesium intake, either from foods or from supplements, could offer measurable benefits for brain longevity.

Sources and Recommended Intake of Magnesium

The recommended dietary allowance (RDA) of magnesium is 420 mg/day for men and 320 mg/day for women, as established by the U.S. Food and Nutrition Board.²²

In foods, magnesium is found most abundantly in leafy greens, seeds, nuts, legumes, and whole grains, for example.²² However, these foods may not always supply the expected amount of magnesium (and other nutrients). That’s because modern agricultural practices and food processing have significantly diminished magnesium availability in conventional crops.^23,24 As a result, many people do not get sufficient levels of magnesium in their diet, leading to magnesium insufficiency in the body.²⁵ 

Magnesium supplements are a good option to complement food sources of magnesium and meet the RDA for magnesium. While excessive intake from food poses no risks, supplemental magnesium may cause gastrointestinal side effects. The recommended upper intake level for magnesium from supplements is 350 mg/day.²² 

Maintaining optimal magnesium levels through diet and supplements is essential for both physical and cognitive well-being. Magnesium is undeniably a cornerstone of brain health, energy metabolism, and cognitive longevity, offering a simple and powerful strategy to support aging brains.

References:

1. J.H.F. de Baaij, J.G.J. Hoenderop, R.J.M. Bindels, Magnesium in man: implications for health and disease, Physiol. Rev. 95 (2015) 1–46.
2. S. Brady, G. Siegel, R. Wayne Albers, D. Price, Basic Neurochemistry: Principles of Molecular, Cellular, and Medical Neurobiology, Academic Press.
3. E. Poleszak, Benzodiazepine/GABA(A) receptors are involved in magnesium-induced anxiolytic-like behavior in mice, Pharmacol. Rep. 60 (2008) 483–489.
4. C. Gottesmann, GABA mechanisms and sleep, Neuroscience 111 (2002) 231–239.
5. J.P. Ruppersberg, E. v. Kitzing, R. Schoepfer, The mechanism of magnesium block of NMDA receptors, Semin. Neurosci. 6 (1994) 87–96.
6. P. Paoletti, C. Bellone, Q. Zhou, NMDA receptor subunit diversity: impact on receptor properties, synaptic plasticity and disease, Nat. Rev. Neurosci. 14 (2013) 383–400.
7. M. Afsharfar, M. Shahraki, M. Shakiba, O. Asbaghi, A. Dashipour, The effects of magnesium supplementation on serum level of brain derived neurotrophic factor (BDNF) and depression status in patients with depression, Clin. Nutr. ESPEN 42 (2021) 381–386.
8. J.A.M. Maier, L. Locatelli, G. Fedele, A. Cazzaniga, A. Mazur, Magnesium and the Brain: A Focus on Neuroinflammation and Neurodegeneration, Int. J. Mol. Sci. 24 (2022). https://doi.org/10.3390/ijms24010223.
9. R. Yamanaka, Y. Shindo, K. Oka, Magnesium Is a Key Player in Neuronal Maturation and Neuropathology, Int. J. Mol. Sci. 20 (2019). https://doi.org/10.3390/ijms20143439
10. V. Romeo, A. Cazzaniga, J.A.M. Maier, Magnesium and the blood-brain barrier in vitro: effects on permeability and magnesium transport, Magnes. Res. 32 (2019) 16–24.
11. M. Barbagallo, L.J. Dominguez, Magnesium and aging, Curr. Pharm. Des. 16 (2010) 832–839.
12. M. Barbagallo, N. Veronese, L.J. Dominguez, Magnesium in Aging, Health and Diseases, Nutrients 13 (2021). https://doi.org/10.3390/nu13020463.
13. E.S. Ford, A.H. Mokdad, Dietary magnesium intake in a national sample of US adults, J. Nutr. 133 (2003) 2879–2882.
14. L.J. Dominguez, N. Veronese, M. Barbagallo, Magnesium and the hallmarks of aging, Nutrients 16 (2024) 496.
15. A.E. Kirkland, G.L. Sarlo, K.F. Holton, The Role of Magnesium in Neurological Disorders, Nutrients 10 (2018). https://doi.org/10.3390/nu10060730.
16. N. Cherbuin, R. Kumar, P.S. Sachdev, K.J. Anstey, Dietary Mineral Intake and Risk of Mild Cognitive Impairment: The PATH through Life Project, Front. Aging Neurosci. 6 (2014) 4.
17. M. Ozawa, T. Ninomiya, T. Ohara, Y. Hirakawa, Y. Doi, J. Hata, K. Uchida, T. Shirota, T. Kitazono, Y. Kiyohara, Self-reported dietary intake of potassium, calcium, and magnesium and risk of dementia in the Japanese: the Hisayama Study, J. Am. Geriatr. Soc. 60 (2012) 1515–1520.
18. S. Fujita, S. Mori, K. Onda, S. Hanaoka, Y. Nomura, T. Nakao, T. Yoshikawa, H. Takao, N. Hayashi, O. Abe, Characterization of brain volume changes in aging individuals with normal cognition using serial magnetic resonance imaging, JAMA Netw. Open 6 (2023) e2318153.
19. H. Tabatabaei-Jafari, M.E. Shaw, N. Cherbuin, Cerebral atrophy in mild cognitive impairment: A systematic review with meta-analysis, Alzheimers Dement. (Amst.) 1 (2015) 487–504.
20. Y. Uchida, K. Nishimaki, A. Soldan, A. Moghekar, M. Albert, K. Oishi, Acceleration of brain atrophy and progression from normal cognition to mild cognitive impairment, JAMA Netw. Open 7 (2024) e2441505.
21. K. Alateeq, E.I. Walsh, N. Cherbuin, Dietary magnesium intake is related to larger brain volumes and lower white matter lesions with notable sex differences, Eur. J. Nutr. 62 (2023) 2039–2051.
22. Institute of Medicine, Food and Nutrition Board, Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride, National Academies Press, 1999.
23. V. Worthington, Nutritional quality of organic versus conventional fruits, vegetables, and grains, J. Altern. Complement. Med. 7 (2001) 161–173.
24. R. Cazzola, M. Della Porta, M. Manoni, S. Iotti, L. Pinotti, J.A. Maier, Going to the roots of reduced magnesium dietary intake: A tradeoff between climate changes and sources, Heliyon 6 (2020) e05390.
25. J.J. DiNicolantonio, J.H. O’Keefe, W. Wilson, Subclinical magnesium deficiency: a principal driver of cardiovascular disease and a public health crisis, Open Heart 5 (2018) e000668.