Data collected over the course of 14.7 years from 58,615 healthy Japanese aged between 40 and 79 indicated similar reductions in the risk of individual cardiovascular events, such as stroke and coronary heart disease.
Writing in Atherosclerosis, the researchers state that magnesium’s heart benefits are biologically plausible, given a well-reported link between the mineral and improved blood pressure, including a recent meta-analysis in the European Journal of Clinical Nutrition.
Magnesium may also benefit heart health by suppressing irregular heartbeats, or by inhibiting inflammation, they added.
Dietary sources of magnesium include green, leafy vegetables, meats, starches, grains and nuts, and milk. Earlier dietary surveys show that a large portion of adults does not meet the RDA for magnesium (320 mg per day for women and 420 mg per day for men).
Recently, scientists from the Karolinska Institutet in Stockholm, Sweden reported that, data pooled from seven prospective studies revealed that, for every 100 mg per day increase in magnesium intake, the risk of stroke was reduced by about 9% (American Journal of Clinical Nutrition).
Using data from the Japan Collaborative Cohort (JACC) Study, the researchers documented 2,690 deaths from cardiovascular disease over the course of almost 15 years, with the highest dietary intakes of magnesium linked to a 50% reduction in the risk of death from heart disease.
When the researchers factored in calcium and potassium weakened the link, but this may be because many of the magnesium-rich foods are also rich sources of calcium and potassium.
“It was difficult to determine whether the cardioprotective effects observed in this study were attributed repeatedly to dietary magnesium, calcium or potassium intake,” they said. “However, in the present study, reduced mortality from coronary heart disease, heart failure and total cardiovascular disease associated with dietary magnesium intake was maintained after dietary calcium intake was taken into account.”
Volume 221, Issue 2, April 2012, Pages 587–595, doi: 10.1016/j.atherosclerosis.2012.01.034
“Associations of dietary magnesium intake with mortality from cardiovascular disease: The JACC study”
Authors: W. Zhang, H. Iso, T. Ohira, C. Date, A. Tamakoshi, JACC Study Group