Supplemental magnesium may reduce blood pressure in people with high blood pressure, but seemingly normal magnesium levels.
The randomized controlled trial assigned 155 people to receive either daily supplements of 300 mg elemental magnesium in the magnesium oxide form or a placebo for 12 weeks (1). At the end of the study, no significant differences were observed between the magnesium or placebo groups. However, when the researchers looked specifically at individuals with hypertension, significant decreases in both systolic and diastolic blood pressure were observed in the magnesium group (17.1 and 3.4 mmHg, respectively), compared to placebo (6.7 and 0.8 mmHg, respectively). On the other hand, the supplements had no effect on the blood pressure measurements of individuals with normal blood pressure.
The researchers suggest that magnesium supplementation may help prevent the progression of hypertension in non-diabetic overweight people with higher blood pressure and normal magnesium blood concentrations. However, mechanisms of counter-regulation preventing further blood pressure increase remain to be elucidated.
The study adds to findings from epidemiological studies which reported that more magnesium, potassium and calcium may reduce the risk of hypertension in certain populations.
High blood pressure (hypertension), defined as having a systolic and diastolic blood pressure (BP) greater than 140 and 90 mmHg, is a major risk factor for cardiovascular disease (CVD) ? a disease that causes almost 50% of deaths in Europe.