According to the Office of Dietary Supplements, magnesium is the fourth most abundant mineral in the human body, where it participates in more than 300 biochemical reactions. Fifty to 60 percent of your total body stores of magnesium are sequestered within your bones and teeth, with nearly all the remainder being contained within your cells. Only 1 percent of your magnesium is circulating in your bloodstream at any given time. The magnesium in your cells and tissue fluids is instrumental in many physiologic processes, including blood pressure regulation.
Functions
As an intracellular nutrient, magnesium assists in a variety of enzymatic reactions, many of which are needed for protein and carbohydrate metabolism. Magnesium is instrumental in the synthesis and function of DNA and RNA, and it participates in cellular signaling by facilitating the transfer of phosphate groups between biological molecules. The Linus Pauling Institute at Oregon State University reports that magnesium is required for the transport of ions, such as calcium, potassium and sodium, across cell membranes, a property that partially accounts for magnesium's role in blood pressure regulation.
Epinephrine
Blood pressure is influenced by a number of factors, including heart rate, blood volume, arterial diameter and epinephrine levels. Factors that slow heart rate, decrease blood volume, increase arterial diameter or inhibit the release of stimulatory hormones tend to decrease your blood pressure. A study published in the October 2009 "British Journal of Anesthesia" demonstrated that magnesium blunted the release of epinephrine during certain surgical procedures, thereby exerting an antihypertensive effect and lowering patients' blood pressures.
Ion Movement
Magnesium plays a major role in controlling the movement of ions, such as calcium, potassium and sodium, across cell membranes. When calcium enters the smooth muscles that surround your arteries, the muscles contract, the vessels constrict and your blood pressure rises. As demonstrated by a study published in the December 2000 issue of "Chest," magnesium inhibits calcium's entry into smooth muscle cells, thereby allowing your arteries to dilate, which results in a lowering of your blood pressure.
Considerations
Magnesium helps to regulate your blood pressure through various mechanisms, including inhibition of epinephrine's effects and decreasing the movement of calcium ions across cell membranes. According to Dr. Elson Haas, author of "Staying Healthy with Nutrition," magnesium deficiency is fairly common in Western cultures. Processing and cooking removes much of the magnesium from foods, and many people don't eat sufficient amounts of fresh fruits and vegetables, which are rich in magnesium. Recommended dietary allowances for magnesium range from 30 mg for infants to 420 mg for adult males. If you have high blood pressure, ask your doctor if you should take extra magnesium.
References
- Office of Dietary Supplements, National Institutes of Health: Magnesium
- Linus Pauling Institute at Oregon State University: Magnesium
- "British Journal of Anesthesia"; Magnesium Sulphate Attenuates Arterial Pressure Increase during Laparoscopic Cholecystectomy; D. Jee, et al.; October 2009
- "Chest"; The Preventive Effect of Magnesium on Coronary Spasm in Patients with Vasospastic Angina; H. Teragawa, et al.; December 2000
- "Staying Healthy with Nutrition: Magnesium"; Elson M. Haas, M.D.; 2006
