A meta-analysis published inHypertensionfound that supplementation with magnesium may lower blood pressure. The analysis included 34 randomized, double-blind, placebo-controlled trials composed of 2,028 normotensive or hypertensive subjects.  The subjects, of which 55% were men and 45% were women, ranged in age between 18 and 84 years; with 1,010 participants receiving magnesium supplementation and 1,018 taking placebo. Results showed that compared to placebo, a median dose of 368 g/day of magnesium over a median duration of three months led to overall reductions in systolic (2.00 mm Hg) and diastolic blood pressure (1.78 mm Hg), while also elevating serum magnesium levels.

“Mg plays a role in the pathogenesis of hypertension mainly through alerting vascular smooth muscle cell function and the peripheral vascular resistance,” explain the authors. “As a cofactor of enzymes in signal transduction pathways involved in vascular contraction, Mg is able to inhibit the vasoconstriction induced by cytosolic accumulation of calcium concentrations.“

While the mechanisms of magnesium’s antihypertensive effects have been identified by laboratory studies, the association between low serum magnesium and hypertension remains controversial, with previous studies offering inconsistent results, say the authors.

This analysis of 34 randomized controlled studies, the authors believe, “provided sufficient power to depict the dose–response analysis for both [blood pressures] and serum Mg.” However, some limitations to consider are the inclusion of small trials with relatively high drop-out rates, measuring magnesium status with serum magnesium which may not be the optimal biomarker and due to a lack of detailed information, the inability to determine acute versus chronic effects of magnesium supplement, to name a few.

Published in WholeFoods Magazine, September 2016