A healthy diet rich in green leafy vegetables, legumes, nuts, seeds, and whole grains could lower blood pressure.
With high blood pressure affecting around 70 million people in the U.S. and increasing the risk of two of the leading causes of death for Americans - heart disease and stroke - preventing or controlling blood pressure is an essential healthcare objective.
Labeled the "silent killer," due to often having no warning signs or symptoms, high blood pressure is a common and often dangerous condition.
A meta-analysis, funded by the Indiana University School of Medicine Strategic Research Initiative, details positive results that show an association between a daily intake of magnesium and a reduction in blood pressure.
Magnesium is already recognized as essential for over 300 biochemical reactions in the body.
While there has been ongoing research into whether magnesium has a significant effect on high blood pressure, it has been widely documented to maintain normal nerve and muscle function, maintain a steady heartbeat, support a healthy immune system, and help bones to remain strong.
The new research includes data from 34 clinical trials, with a total of 2,028 participants.
The researchers found that those participants who had a median of 368 mg of magnesium daily for an average of 3 months recorded a decrease in systolic blood pressure of 2.00 mm Hg and a decrease in diastolic blood pressure of 1.78 mm Hg.
"With its relative safety and low cost, magnesium supplements could be considered as an option for lowering blood pressure in high-risk persons or hypertension patients."
Yiqing Song, M.D., Sc.D., lead author, Indiana University, Indianapolis
Song and colleagues also observed that patients who had an intake of 300 mg of magnesium per day had elevated blood magnesium levels and reduced blood pressure within a month.
Elevated blood magnesium levels were associated with an improvement in blood flow, which has been named as a factor linked to lowered blood pressure.
Adequate magnesium intake can be achieved through a healthy diet
Although 82 percent of the magnesium supplement dosages in the study were equal to or greater than the U.S. Recommended Dietary Allowance (RDA) for adults, the American Heart Association (AHA) say that magnesium, as a supplement, may not be necessary for the desired effect of maintaining blood pressure.
AHA spokesperson Penny Kris-Etherton, Ph.D., Prof. of Nutrition at the University of Pennsylvania, says, "This study underscores the importance of consuming a healthy diet that provides the recommended amount of magnesium as a strategy for helping to control blood pressure."
She adds, "Importantly, this amount of magnesium (368 mg/day) can be obtained from a healthy diet that is consistent with AHA dietary recommendations."
Yiqing Song notes, "Consistent with previous studies, our evidence suggests that the anti-hypertensive effect of magnesium might be only effective among people with magnesium deficiency or insufficiency."
"Such suggestive evidence indicates that maintenance of optimal magnesium status in the human body may help prevent or treat hypertension," he concludes.
The researchers additionally discovered that magnesium supplementation might only decrease blood pressure in people who have a deficiency in magnesium.
Limitations of the meta-analysis include the small number of participants in each study and significant dropout rates. However, the studies with lower dropout rates expressed a higher reduction in blood pressure.
Magnesium is found in green leafy vegetables, legumes, nuts, seeds, whole grains, some breakfast cereals, and other fortified food.