Reference
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.
Design
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.
