Magnesium and Blood Pressure
Nutrition Research Newsletter, July-August, 1994
Magnesium is believed to play a role in the regulation of blood pressure. Several population studies have shown an inverse association between magnesium intake and blood pressure, but it is not clear whether supplementation with this mineral can have a significant effect on blood pressure in hypertensive subjects. The study summarized here was a double-blind controlled trial of magnesium supplementation in hypertensive women.
In a trial conducted in the town of Zoetermeer in The Netherlands, 91 middle-aged and elderly women with untreated mild to moderate hypertension received 20 mmol Mg/day of magnesium aspartate-HCl (485 mg) or placebo for six months. The 20 mmol dose more than doubled the women's magnesium intakes.
The supplement was well tolerated and was not associated with an increased frequency of diarrhea. There were no significant differences in blood pressure between the supplement and placebo groups after three months of treatment. However, after six months, systolic blood pressure had fallen by 2.7 mm Hg (95% CI 1.2-6.7; P = 0.18) and diastolic blood pressure had fallen by 3.4 mm Hg (95% CI 1.3-5.6; P = 0.003) in the supplemented group.
These findings suggest that increased magnesium intake may be of value in the treatment of mild to moderate hypertension. The dose used in this study, 20 mmol/day, would be difficult to achieve by dietary changes alone. Supplementation would probably be necessary in order to increase magnesium intake to this extent.
Jacqueline CM Witteman, Diederick E Grobbee, Frans HM Derkx, Roger Bouillon, Anthony M de Bruijn, and Albert Hofman, Reduction of Blood Pressure with Oral Magnesium Supplementation in Women with Mild to Moderate Hypertension, American J Clinical Nutrition 60(1): 129-135 (July 1994)
