Researchers publishing in the European Journal of Nutrition looked into magnesium as a possible candidate for preventing dementia, focusing on potential improvements to brain volumes and reduced white matter lesions [1].
Building from previous research
Brain health is critical over the long term, and dementia can significantly reduce quality of life for older people. Dementia is currently incurable, so researchers are looking into ways to prevent or delay this disease. Previous research has suggested that magnesium could reduce the risk of dementia and linked its consumption to better cognitive health [2, 3].
To investigate magnesium as a possible way to improve brain health, researchers used data from UK Biobank, analyzing 6,001 people aged 40 to 73 years. An online dietary survey was used to measure the amount of magnesium consumed. The survey was conducted several times during the study period in order to reduce the effects of participants misremembering and to account for changes in their diets.
Magnesium is correlated with brain health
The white matter is a network of nerve fibers, often surrounded by a protective sheath. White matter lesions are abnormal changes in this protective sheath. White matter function to allow different areas of grey matter to communicate. An increase in white matter lesions is associated with cognitive decline, disability, and mortality [4].
In this study, the researchers observed that higher dietary magnesium intake was associated with larger brain volumes in men and women. These differences were very small, ranging from 0.001% to 0.0023%, depending on the brain structure. The effect of magnesium intake reached statistical significance only for women, even though their magnesium intake was slightly lower than men.
Post-menopausal women had the strongest association
The authors examined the baseline magnesium intake and whether it was increasing or decreasing. They created three classes of magnesium intake: “high-decreasing,” “low-increasing,” and “stable normal.” This kind of analysis provides insight into how people’s diets change over time.
A “high-decreasing” course was correlated with larger brain volumes in women, particularly post-menopausal women. This was contrary to the researchers’ expectations; they predicted that decreasing magnesium levels over the course of the study would be associated with lower brain volumes.
The researchers were unsure how to explain this observation. They suggested that magnesium intake at the beginning of the study represented a general lifetime average, and they further hypothesized that such a long-term intake could result in the observed differences in brain aging. This would also explain their other results, which showed that women who followed a “normal-stable” or “low-increasing” course had smaller brain volumes and larger white matter lesions.
The correlation varied across brain regions
The association between magnesium and brain volume was reported to differ across brain regions, being strongest in the grey matter and the hippocampus. Those brain regions play a role in the control of movement, memory, emotions, and learning [5, 6].
The researchers’ model predicts that, on average, a person with a high magnesium intake (= 550 mg/day) has slightly larger grey matter and right hippocampus volumes than someone with a magnesium intake of about 350 mg/day. This predicted difference corresponds to roughly 1 year of typical aging among 55-year-olds.
If this effect applies to other populations, it could be a helpful tool for improving overall health. The authors estimate that increasing magnesium intake by 41% could benefit brain health, cognitive abilities, and dementia prevention.
More questions remain
Increasing dietary intake of magnesium may be an easy way to improve brain health and prevent dementia, particularly if it begins at age 40 or earlier. However, the best age and optimal dose of dietary magnesium intake have yet to be defined.
Similarly, the mechanism of magnesium’s influence on the brain is also still unknown. These researchers proposed possible mechanisms for this observation, but they agree that more experiments are needed to explain the connection between magnesium consumption and brain health.
The optimal dose still needs to be established, and more research confirming the findings is required. However, nutritionists have reported in multiple studies that a diet containing magnesium-rich foods, such as green vegetables, is a good idea [7].
Literature
[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, 10.1007/s00394-023-03123-x. Advance online publication. https://doi.org/10.1007/s00394-023-03123-x\
[2] 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 (New York, N. Y.), 8(1), e12250. https://doi.org/10.1002/trc2.12250
[3] Ozawa, M., Ninomiya, T., Ohara, T., Hirakawa, Y., Doi, Y., Hata, J., Uchida, K., Shirota, T., Kitazono, T., & Kiyohara, Y. (2012). Self-reported dietary intake of potassium, calcium, and magnesium and risk of dementia in the Japanese: the Hisayama Study. Journal of the American Geriatrics Society, 60(8), 1515–1520. https://doi.org/10.1111/j.1532-5415.2012.04061.x
[4] Sharma R, Sekhon S, Cascella M. White Matter Lesions. In: StatPearls. StatPearls Publishing, Treasure Island (FL); 2022. PMID: 32965838.
[5] Mercadante AA, Tadi P. Neuroanatomy, Gray Matter. In: StatPearls. StatPearls Publishing, Treasure Island (FL); 2022. PMID: 31990494.
[6] Anand, K. S., & Dhikav, V. (2012). Hippocampus in health and disease: An overview. Annals of Indian Academy of Neurology, 15(4), 239–246. https://doi.org/10.4103/0972-2327.104323
[7] Gröber U, Schmidt J, Kisters K. Magnesium in Prevention and Therapy. Nutrients. 2015; 7(9):8199-8226. https://doi.org/10.3390/nu7095388
