Dietary Magnesium and Stroke Prevention

Study discusses the correlation between increased dietary magnesium intake and stroke reduction

By Carolyn Dean, MD, ND

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Larsson SC, Orsini N, Wolk A. Dietary magnesium intake and risk of stroke: a meta-analysis of prospective studies. Am J Clin Nutr. 2012;95(2):362-366.


A meta-analysis on magnesium and risk of stroke using relevant studies from PubMed and EMBASE (Jan 1966–Sept 2011) and references in those articles. Prospective studies were included that reported relative risks with 95% confidence intervals (CI) of stroke for 3 categories of magnesium intake. Seven studies yielding 241,378 participants and 6,477 cases of stroke were analyzed.

Key Findings

For each 100 mg increase in magnesium intake, risk of stroke was reduced by 8% (combined RR: 0.92; 95% CI: 0.88, 0.97). This association was found for ischemic stroke (RR: 0.91; 95% CI: 0.87, 0.96) but not intracerebral hemorrhagic (RR: 0.96; 95% CI: 0.84, 1.10) or subarachnoid (RR: 1.01; 95% CI: 0.90, 1.14) stroke.
One health practice that you, as practitioners, can easily encourage is a higher intake of magnesium for your patients.

Practice Implications

The authors propose that the reduction in stroke risk may be due to dietary magnesium’s effects on several risk factors for stroke. Magnesium has been shown to mitigate some of these risk factors, including:
  • Hypertension 1, 2
  • Metabolic syndrome 3
  • Type-2 diabetes 2, 4
Randomized clinical trials show that magnesium supplementation modestly reduces diastolic blood pressure 5 and modestly reduces fasting C-peptide and insulin concentrations.6
Animal studies have shown that high-magnesium diets have favorable effects on plasma glucose and blood lipid concentrations,7 and magnesium deficiency increases the susceptibility of lipoproteins to peroxidation.8
The levels of dietary magnesium have gradually declined in the United States, from a high of 500 mg/day in 1900 to barely 175–225 mg/day today.9 The National Academy of Sciences has determined that most American men obtain about 80 percent of the recommended daily allowance (RDA) and women average only 70 percent.10
There are over 325 magnesium-dependent enzymes in the human body that allow magnesium to function as a cofactor in a wide range of metabolic reactions.9
Given the prevalence of magnesium deficiency, no practitioner should assume that his/her patients are replete. Dietary measures to ensure adequate magnesium intake should always be considered.
One health practice that you, as practitioners, can easily encourage is a higher intake of magnesium for your patients. The foods to advise are deep green leafy vegetables, whole grains, nuts, and seeds. The oral supplements come in many forms. However, magnesium oxide is the least absorbed form. If a patient finds the laxative effect too strong with oral supplements, you could suggest magnesium oils, creams, and gels or magnesium baths with Epsom salts.

About the Author

Carolyn Dean, MD, ND, author of The Magnesium Miracle (Ballantine Books, 2007) and many other books/booklets, has been at the forefront of natural medicine for more than 30 years. She holds a medical license in California and is a graduate of the Ontario Naturopathic College. She has a complimentary newsletter and an online wellness program called Future Health Now!, which is her answer to the current healthcare crisis. Her web site is


1. Ma J, Folsom AR, Melnick SL, et al. Associations of serum and dietary magnesium with cardiovascular disease, hypertension, diabetes, insulin, and carotid arterial wall thickness: the ARIC study. Atherosclerosis Risk in Communities Study. J Clin Epidemiol. 1995;48:927-940.
2. Ohira T, Peacock JM, Iso H, Chambless LE, Rosamond WD, Folsom AR. Serum and dietary magnesium and risk of ischemic stroke: the Atherosclerosis Risk in Communities Study. Am J Epidemiol. 2009;169:1437-1444.
3. Song Y, Manson JE, Cook NR, Albert CM, Buring JE, Liu S. Dietary magnesium intake and risk of cardiovascular disease among women. Am J Cardiol. 2005;96:1135-1141.
4. Larsson SC, Wolk A. Magnesium intake and risk of type 2 diabetes: a meta-analysis. J Intern Med. 2007;262:208-214.
5. Dickinson HO, Nicolson DJ, Campbell F, et al. Magnesium supplementation for the management of essential hypertension in adults. Cochrane Database Syst Rev. 2006;3: CD004640.
6. Chacko SA, Sul J, Song Y, et al. Magnesium supplementation, metabolic and inflammatory markers, and global genomic and proteomic profiling: a randomized, doubleblind, controlled, crossover trial in overweight individuals. Am J Clin Nutr. 2011;93:463-473.
7. Soltani N, Keshavarz M, Dehpour AR. Effect of oral magnesium sulfate administration on blood pressure and lipid profile in streptozocin diabetic rat. Eur J Pharmacol. 2007;560:201-205.
8. Rayssiguier Y, Gueux E, Bussière L, Durlach J, Mazur A. Dietary magnesium affects susceptibility of lipoproteins and tissues to peroxidation in rats. J Am Coll Nutr. 1993;12:133-137.
9. Altura BM. Introduction: importance of Mg in physiology and medicine and the need for ion selective electrodes. Scand J Clin Lab Invest. 1994;54(217[Suppl]):5-9.
10. Institute of Medicine, Dietary Reference Intake for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride, National Academy Press, Washington DC, 1997.