Magnesium

Current research findings indicate that magnesium plays a decisive role in the development, prevention and potentially also treatment of dementia.

Magnesium is an essential mineral that is involved in over 600 enzymatic reactions in the body. It plays a central role in protein synthesis, muscle and nerve function, the transmission of signals between nerve cells, the regulation of blood sugar levels and the maintenance of stable blood pressure.

Around 99% of all magnesium is found in bones, muscles and soft tissue, of which around 50-60% is in the bones. However, the magnesium content in the bones decreases with increasing age – this means that the body’s own stores can no longer be fully mobilized in the event of a deficiency.

A long-term magnesium deficiency can have far-reaching consequences: It impairs the communicative balance between nerve cells, can reduce cognitive performance and is increasingly associated with an increased risk of dementia.

To keep our magnesium levels in balance, we should make sure we eat a magnesium-rich diet every day. Wholesome, natural foods are particularly valuable sources of this mineral:

• Wholegrain and pseudograins such as quinoa, amaranth, buckwheat, millet, oatmeal, whole grain rice, whole grain flour or whole grain bread
• Legumes (or their fermented offshoots) such as soybeans, tempeh, tofu, white beans, black beans, kidney beans, chickpeas or lentils
• Nuts and seeds such as pumpkin seeds, sunflower seeds, chia seeds and almonds
• Green vegetables such as spinach, chard, kale, broccoli and rocket
• fruits such as bananas and dried fruits (apricots, dates, figs, bananas) [4].

The effect of magnesium in the brain

The mechanism by which magnesium most likely reduces the risk of dementia is not yet conclusively known. However, research findings point to several mechanisms of action of magnesium that protect the brain and support cognitive performance:

• Promotes blood circulation: Magnesium relaxes the blood vessels by inhibiting certain calcium channels in the vessel walls. As a result, the blood flows better and the brain is optimally supplied with oxygen and nutrients.
• Protects the nerve cells: Magnesium plays a central role in the health of the nervous system. It acts as a natural regulator in the nerve cells by blocking the so-called NMDA channels at low activity, thereby reducing neuronal excitability. In the absence of magnesium, these NMDA receptors can become overly active – a condition associated with neuronal damage, neurodegenerative diseases, epileptic seizures and migraines. A good supply of magnesium therefore keeps the nerve cells healthy.
• Reduces free radicals: Magnesium helps to protect the cells from harmful molecules known as free radicals. These occur in particular when the cells receive too little oxygen or blood circulation is disturbed – for example in the event of stress, inflammation or circulatory problems. Free radicals can attack the cell structure and thus damage nerve cells in particular.
• Supports energy production: Magnesium supports the mitochondria, the “power plants” of our cells, and ensures that they produce energy efficiently. This provides the brain with sufficient energy and the nerve cells remain active and efficient.
• Has an anti-inflammatory effect: Magnesium can reduce the release of pro-inflammatory cytokines (TNF-alpha, IL-6, IL-1) which can trigger chronic inflammation in the brain and accelerate cognitive decline [8,12].

What we know about magnesium and dementia

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Magnesium concentrations in the blood in dementia

Studies show that a magnesium deficiency could promote the progression of Alzheimer’s disease. Alzheimer’s patients have significantly lower magnesium levels in the blood (serum and plasma) compared to healthy people, and the overall magnesium circulation is also reduced. Previous studies have also shown that the magnesium concentration in regions of the brain affected by Alzheimer’s – such as the ammonial horn, the entorhinal cortex and the frontal cortex – is lower. The reasons for this have not yet been conclusively clarified and could lie in both an altered permeability of the blood-brain barrier and a dietary magnesium deficiency [2,11].

In addition, studies show that magnesium levels that are too low (<0.79 mmol/L) are associated with an increased risk of dementia. Serum levels in the range of 0.80-0.89 mmol/L, on the other hand, appear to have preventive effects [11].

Magnesium intake in dementia

Adequate magnesium intake, whether through diet or supplementation, can have a preventive effect against dementia. A magnesium deficiency can increase the risk of dementia. Magnesium appears to be particularly effective in combination with an adequate supply of other vitamins.

Magnesium intake via the diet

Studies show that people with sufficient magnesium intake have larger brain volumes, particularly in the gray matter and hippocampus. At the same time, fewer lesions occur in the white matter and the risk of dementia is significantly reduced [1]. The positive effect of magnesium on cognitive function is particularly evident if the vitamin D level in the blood is also sufficient (>50ng/ml) [9,10]. Another study showed that a higher vegetable intake (270-400 g/day) – combined with an increased intake of magnesium, calcium, potassium, vitamins and fiber – is associated with a lower risk of Alzheimer’s disease, but not vascular dementia [5].

In addition, the ratio of calcium to magnesium in the diet also appears to play an important role. With a low calcium-magnesium ratio (< 1.69), a high magnesium intake (> 267 mg/day) can increase the risk of dementia by up to four times. With a higher ratio (> 1.69), however, there is no correlation. Researchers assume that a calcium-magnesium ratio of between 1.7 and 2.6 could be optimal for brain health [7].

Magnesium supplements against dementia?

Several studies indicate that an adequate intake of magnesium can reduce the risk of dementia. Magnesium supplements are available in various forms, which differ in terms of bioavailability, tolerability and effect. Organic compounds such as magnesium citrate, magnesium chloride or magnesium glycinate are usually better absorbed by the body than inorganic forms such as magnesium oxide.

One form in particular, magnesium L-threonate, is the focus of current research. Magnesium is bound to the substance L-threonic acid. L-threonic acid is a degradation product of vitamin C and occurs naturally in the body. Studies have shown that the major difference between magnesium L-threonate and all other magnesium compounds is that it can cross the blood-brain barrier particularly well, thereby increasing the magnesium level in the brain. This can have a positive effect on memory, concentration and mental performance.

Liu et al.

In a study by Lui et al., 51 people aged between 50 and 70 with mild cognitive impairment or incipient dementia were divided into two groups. The intervention group received 1.5-2g/day of the magnesium supplement MMFS-01 for 12 weeks. After just 6 weeks, this group showed a significant increase in intracellular magnesium in the red blood cells.

At the same time, mental performance improved significantly. After 6 weeks, there were positive effects on working memory and executive functions (e.g. planning, concentration, problem solving). After 12 weeks, episodic memory (ability to remember events) also improved. MMFS-01 also reduced cognitive fluctuations: Participants reported fewer “bad days”, more mental stability and improved everyday functioning [6].

Zhang et al.

Another study by Zhang et al. examined the effect of Magtein, a preparation containing 400 mg magnesium L-threonate, 80 IU vitamin D, 12 mg vitamin C, 4 mg vitamin B6 and 50 mg phosphatidylserine.

102 healthy adults aged 18 to 65 were randomly divided into two groups. The intervention group received 2 g of Magtein daily for 30 days. At the end of the study, this group showed a significant improvement in all five memory areas tested, indicating an increase in cognitive performance [13].

To date, only a few and less conclusive studies are available on the effectiveness of other forms of magnesium such as magnesium glycinate or magnesium oxide.

Click here to find out more about magnesium L-threonate.

Dosage recommendations

In principle, men should take in at least 350 mg and women 300 mg of magnesium per day. However, the individual requirement can be significantly higher in certain life situations, for example in the case of increased physical or mental strain, stress, heavy sweating, pregnancy or breastfeeding. Diseases of the gastrointestinal tract or impairment of the intestinal mucosa can also reduce absorption. It is therefore advisable to have the magnesium level in your whole blood checked.

The Federal Institute for Risk Assessment recommends a maximum daily dose of 250 mg magnesium for the oral intake of food supplements. Above this amount, sensitive people may experience softer stools or diarrhea. However, this is generally harmless and can be used specifically for constipation, for example [3]. However, supplementation should always be carried out in consultation with your doctor or therapist.

Conclusion

Magnesium is an essential nutrient for brain health and plays an important role in numerous neuroprotective processes. A balanced magnesium level in the blood is associated with a low risk of dementia, while too low a level can increase the risk. An adequate intake of magnesium in the diet can help to reduce the risk of dementia. Magnesium L-threonate in particular has been shown in studies to improve certain cognitive abilities in mild dementia and support brain health as a preventative measure.

You can have your magnesium status determined as part of a whole blood test. You should discuss the intake of dietary supplements with your doctor or therapist beforehand.

Find out everything you need to know about the recommended intake of magnesium here.

If you would like to find out more about dementia, its prevention and treatment, click here.

References

1. Alateeq, K., Walsh, E. I., & Cherbuin, N. (2023). Dietary magnesium intake is related to larger brain volumes and lower white matter lesions with notable sex differences. European Journal of Nutrition, 2(5), 2039-2051. https://doi.org/10.1007/s00394-023-03123-x
2. Du, K., Zheng, X., Ma, Z.-T., Lv, J.-Y., Jiang, W.-J., & Liu, M.-Y. (2022). Association of Circulating Magnesium Levels in Patients With Alzheimer’s Disease From 1991 to 2021: A Systematic Review and Meta-Analysis. Frontiers in Aging Neuroscience, 13. https://doi.org/10.3389/fnagi.2021.799824
3. EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA), Turck, D., Bohn, T., Castenmiller, J., De Henauw, S., Hirsch-Ernst, K. I., Maciuk, A., Mangelsdorf, I., McArdle, H. J., Naska, A., Pentieva, K., Siani, A., Thies, F., Tsabouri, S., Vinceti, M., Aguilera-Gómez, M., Cubadda, F., Frenzel, T., Heinonen, M., … Knutsen, H. K. (2024). Safety of magnesium l-threonate as a novel food pursuant to regulation (EU) 2015/2283 and bioavailability of magnesium from this source in the context of Directive 2002/46/EC. EFSA Journal, 22(3), e8656. https://doi.org/10.2903/j.efsa.2024.8656
4. Gröber, U., Schmidt, J., & Kisters, K. (2015). Magnesium in Prevention and Therapy. Nutrients, 7(9), 8199-8226. https://doi.org/10.3390/nu7095388
5. Kimura, Y., Yoshida, D., Ohara, T., Hata, J., Honda, T., Hirakawa, Y., Shibata, M., Oishi, E., Sakata, S., Furuta, Y., Chen, S., Uchida, K., Nakao, T., Kitazono, T., & Ninomiya, T. (2022). Long-term association of vegetable and fruit intake with risk of dementia in Japanese older adults: The Hisayama study. BMC Geriatrics, 22(1), 257. https://doi.org/10.1186/s12877-022-02939-2
6. Liu, G., WeingerJ. G., Lu, Z.-L., Xue, F., & Sadeghpour, S. (2016). Efficacy and Safety of MMFS-01, a Synapse Density Enhancer, for Treating Cognitive Impairment in Older Adults: A Randomized, Double-Blind, Placebo-Controlled Trial. Journal of Alzheimer’s Disease, 49(4), 971-990. https://doi.org/10.3233/JAD-150538
7. Luo, J., Zhang, C., Zhao, Q., Wu, W., Liang, X., Xiao, Z., Mortimer, J. A., Borenstein, A. R., Dai, Q., & Ding, D. (2022). Dietary calcium and magnesium intake and risk for incident dementia: The Shanghai Aging Study. Alzheimer’s & Dementia: Translational Research & Clinical Interventions, 8(1), e12362. https://doi.org/10.1002/trc2.12362
8. Patel, V., Akimbekov, N. S., Grant, W. B., Dean, C., Fang, X., & Razzaque, M. S. (2024). Neuroprotective effects of magnesium: Implications for neuroinflammation and cognitive decline. Frontiers in Endocrinology, 15. https://doi.org/10.3389/fendo.2024.1406455
9. Tao, M.-H., Chuang, S.-C., Wu, I.-C., Chan, H.-T., Cheng, C.-W., Chen, H.-L., Lee, M. M., Chang, H.-Y., Hsiung, C. A., & Hsu, C.-C. (2024). Cross-sectional and longitudinal associations of magnesium intake and cognition in the Healthy Aging Longitudinal Study in Taiwan. European Journal of Nutrition, 63(8), 3061-3073. https://doi.org/10.1007/s00394-024-03490-z
10. Tao, M.-H., Liu, J., & Cervantes, D. (2022). Association between magnesium intake and cognition in US older adults: National Health and Nutrition Examination Survey (NHANES) 2011 to 2014. Alzheimer’s & Dementia: Translational Research & Clinical Interventions, 8(1), e12250. https://doi.org/10.1002/trc2.12250
11. Varga, P., Lehoczki, A., Fekete, M., Jarecsny, T., Kryczyk-Poprawa, A., Zábó, V., Major, D., Fazekas-Pongor, V., Csípő, T., & Varga, J. T. (2025). The Role of Magnesium in Depression, Migraine, Alzheimer’s Disease, and Cognitive Health: A Comprehensive Review. Nutrients, 17(13), 2216. https://doi.org/10.3390/nu17132216
12. Xu, P., Cui, D., Jin, M., & Sun, L. (2024). Magnesium ions and dementia. Journal of Neurorestoratology, 12(1), 100094. https://doi.org/10.1016/j.jnrt.2024.100094
13. Zhang, C., Hu, Q., Li, S., Dai, F., Qian, W., Hewlings, S., Yan, T., & Wang, Y. (2022). A Magtein®, Magnesium L-Threonate, -Based Formula Improves Brain Cognitive Functions in Healthy Chinese Adults. Nutrients, 14(24), 5235. https://doi.org/10.3390/nu14245235

Image 1 from: shutterstock by Tijana Moraca

Image 2 from: shutterstock from CeltStudio