Magnesium and the Prevention of Dementia

In 2019, 57.4 million people around the world were suffering from dementia and this figure is predicted to rise to 152.8 million by 2050.  Despite extensive research and the testing of many drugs showing potential to treat dementia, no cure has been found.  But what about its prevention?  (1)

Magnesium is a necessary mineral for humans.  It is involved in numerous biochemical processes in the body including energy production; lipid and glucose metabolism and control of blood sugar levels; production of DNA, RNA and protein; muscle contraction, including that of the heart; regulation of blood pressure; strengthening of bones; and calming of inflammation.  In addition, sufficient magnesium ingestion supports normal functioning of brain cells (brain neurons) by protecting them from excitotoxicity (overstimulation of brain receptors that can result in damage or death to neurons).  Excitotoxicity has been implicated in many neurodegenerative conditions, such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, ALS (Lou Gehrig’s disease), multiple sclerosis, and epilepsy. (2,3)

There is mounting evidence for the beneficial effects of good nutrition on cognitive wellbeing and one of the major players in this is magnesium.  Research has shown that chronic magnesium deficiency results in reduced antioxidant capacity in the brain.  Free radicals, a natural byproduct of normal metabolism, are subdued by antioxidants, but, if antioxidant levels are low due to a scarcity of magnesium, the result will be an increase in free radicals which can damage cells and lead to chronic low-grade inflammation. The most common cause of a shortage of magnesium in the elderly is lack of magnesium in the diet. (4,5)

There have been multiple studies performed in the last couple of decades regarding the benefits of magnesium for age-related problems in the brain.

One such study, published in March 2023, looked at the possibility that dementia could be prevented if sufficient intake of magnesium from the diet is sustained over time.  The healthcare data from 6,001 participants of the UK Biobank between the ages of 40 and 73 was analyzed for this research.  The investigators looked at MRI (magnetic resonance imaging) scans, blood pressure measurements and dietary magnesium consumption over 24-hours assessed five times over 16 months.  Results showed that higher ingestion of magnesium was linked to larger brain volumes and smaller white matter lesions in MRI scans.  Both results are associated with less dementia.  No observable links were found between magnesium intake and blood pressure.  This examination determined that, by the age of 55, a person consuming 550 mg or more of magnesium daily had a brain that appeared to be one-year younger compared with those ingesting 350 mg of magnesium a day. (6)

Note: The RDA (Recommended Dietary Allowance) for magnesium in Canada is 400 mg/day for adult males and 320 mg/day for adult females. (10)  The actual average daily intake of magnesium from the diet is 327 mg. (5)

These results suggest that higher magnesium consumption from food may offer early protection of the brain from aging processes and help to prevent cognitive decline.  The study conclusion was that increasing magnesium intake by at least 41% could improve brain health, reduce age-related brain shrinkage, preserve cognitive ability and lower the risk or delay the onset of dementia. These effects were more pronounced in women than in men and in post-menopausal women more than in those who were pre-menopausal. (6)

In 2022, a plant-based diet was scrutinized for associations with cognitive function. Participants were 3,039 older adults from the NHANES (National Health and Nutrition Examination Survey).  A plant-based diet was considered to be one with high intake of plant-sourced foods high in fiber and polyunsaturated fat and low in the intake of animal-sourced foods, saturated fat and protein.  A diet score for each participant was calculated through analysis of principal components of their diet.

Results showed that greater adherence to a plant-based dietary pattern was related to better performance on all cognitive tasks, especially executive function and memory, as well as with reduced inflammation.

Note:  Executive function includes basic cognitive functions needed for self control and managing behaviour.  (7) 

The researchers of this investigation mention several possible mechanisms for the benefits to the brain from eating mostly plants;

  • The BMI of participants decreased during the study. Past study shows that reduced BMI is associated with better cognitive function.
  • The participants who adhered more closely to a plant-based diet experienced lower inflammation levels.
  • High consumption of vegetables and whole grains provides rich sources of magnesium. (7)

Also from 2022, another study examined the intake of magnesium from diet and supplements and found that high total magnesium ingestion was independently associated with better cognition in older adults, especially in those with sufficient vitamin D levels in their blood.  This effect was thought to be due to the ability of magnesium to block receptors in the brain, preventing them from becoming overactive (excitotoxicity) thus reducing oxidative stress and inflammation. Study authors recommend further investigations to uncover the possibility that combining the powers of magnesium and optimal vitamin D levels can achieve greater benefits for cognitive function. (2)

A report from Japan looked at the effects of dietary magnesium, potassium and calcium on dementia.  This trial followed 1,081 middle-aged adults for 17 years and found a 37% lower risk of developing dementia from any cause in those ingesting the highest levels of magnesium compared to those consuming the least amount. For vascular dementia specifically (cognitive impairment caused by impaired blood flow to the brain such as with plaque build-up inside blood vessels), the highest intake of magnesium was associated with 74% lower risk of cognitive impairment.  (8)


Food Sources of Magnesium (9,11)

Eating a diet based on plants is an easy way to obtain enough magnesium to benefit your brain as well as to support the many other biochemical reactions taking place in our bodies in which magnesium is involved.  The following is a list of foods that are good sources of this important mineral.

Whole wheat                     160 mg per cup

Spinach                               157 mg per cup of boiled spinach

Pumpkin seeds                 156 mg per ounce of hulled, roasted seeds

Black beans                        120 mg per cup of cooked beans

Edamame                           100 mg per cup of shelled cooked beans

Quinoa                                118 mg per cup of boiled quinoa

Chia seeds                          111 mg per ounce

Brown rice                         84 mg per 1 cup, cooked

Flaxseed                              80 mg per ounce of whole seeds

Almonds                              80 mg per ounce

Cashews                             75 mg per ounce

Dark chocolate                  64 mg per ounce of dark chocolate containing 70% or higher cocoa solids

Soy milk, plain                  61 mg per 8 ounces

Avocado                              58 mg per fruit

Dark chocolate                  50 mg per ounce of dark chocolate containing 60 to 59% cocoa solids

Peanut butter                    49 mg per 2 tablespoons

Peanuts                               49 mg per ounce of dry roasted nuts

Whole-wheat bread        46 mg per 2 slices

Potatoes                             43 mg per 3.5 ounces of potatoes, baked with skin on

Tofu                                      37 mg per half cup


 Summing up

Given the prediction of rising dementia worldwide during the next thirty years, the spectre of developing cognitive problems is alarming.  Fortunately, science is revealing the importance of magnesium for brain function.   It is a simple act for anyone, regardless of their dietary preferences, to increase their consumption of foods high in magnesium.



2  Tao, M.H., Liu, J., Cervantes, D. Association between magnesium intake and cognition in US older adults: National Health and Nutrition Examination Survey (NHANES) 2011 to 2014. Alzheimers Dement (N Y). 2022 Feb 1; 8(1):e12250. Doi: 10.1002/trc2.12250. PMID: 35128033; PMCID: PMC8804621.

3  Nielsen, F.H. Magnesium deficiency and increased inflammation: current perspectives. J Inflamm Res. 2018 Jan 18; 11: 25-34. Doi: 10.2147/JIR.S136742. PMID: 29403302; PMCID: PMC5783146.

4  Barbagallo, M., Dominguez, L.J. Magnesium and aging. Curr Pharm Des. 2010; 16(7): 832-839. Doi: 10.2174/138161210790883679. PMID: 20388094.


6  Alateeq, K., Walsh, E.I. & Cherbuin, N. Dietary magnesium intake is related to larger brain volumes and lower white matter lesions with notable sex differences. Eur J Nutr . Published online Marh 10, 2023.

7  Ramey, M., Shields, G., Yonelinas, A. Markers of a plant-based diet relate to memory and executive function in older adults. Nutr Neurosci. 2022; 25(2): 276-285. Doi:10.1080/1028415X.2020.1751506.

8  Ozawa, M., Ninomiya, T.,Ohara, T.,Hirakawa, Y., Doi, Y., Hata, J., et al.  Self-Reported Dietary Intake of Potassium, Calcium, and Magnesium and Risk of Dementia in the Japanese: The Hisayama Study.  First published: 02 August 2012












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My name is Debra Harley (BScPhm) and I welcome you to my retirement project, this website. Over the course of a life many lessons are learned, altering deeply-rooted ideas and creating new passions.

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