Benefits of Magnesium Supplements for Heart Health

Filed Under: Heart Health, Food and Nutrition, Nutrients and Additives
Last Reviewed 03/03/2015

Benefits of Magnesium Supplements for Heart Health

Among the top nutrients for heart health, the benefits of magnesium supplements really stand out. Magnesium is used in scores of enzymatic reactions, and it’s necessary for normal muscle function. Unfortunately for many people, they’re seriously low on this mineral.

A shortage can cause or worsen congestive heart failure, atherosclerosis, chest pain (coronary vasospasm), high blood pressure, cardiac arrhythmias, heart muscle disease (cardiomyopathy), heart attack and even sudden cardiac death.

Your cells need a steady supply of magnesium to maintain proper smooth muscle function in your blood vessels. In addition, magnesium supplements can help your body shuttle potassium and sodium, two other essential electrolytes, into and out of cells, maintaining proper balance (homeostasis).

Magnesium deficiencies can lead to muscle weakness and tremors (spasm) and a host of cardiovascular problems ranging from high blood pressure to arrhythmias.

So what’s going on to cause such a depletion of this crucial mineral?

Stress Depletes Magnesium

Your body responds to various types of stressors by releasing the “fight or flight” hormones adrenalin and cortisol. These hormones are fine, and perhaps even life-saving when you are trying to outrun a predator or meet a deadline, but they are only meant to kick in during times of need.

If the stress level in your life is high, especially if you don’t get enough exercise, your bloodstream may be flooded with these hormones on a regular basis, causing magnesium to be released from cells and lost in the urine.

Drugs Deplete Magnesium

If you have a history of heart attack, congestive heart failure or high blood pressure, you may be on diuretics, which can cause magnesium depletion. In a landmark study reported in the early 80s, men with high blood pressure on diuretic therapy had a higher death rate than those whose high blood pressure was left untreated.

It was suggested that many of these men suffered sudden cardiac death from heart rhythm disturbances resulting from a deficiency of magnesium and/or potassium. The study created chaos in the medical establishment, since treating hypertension was thought to reduce cardiovascular complications, including sudden cardiac death.

As a result of this study, many physicians now prescribe magnesium supplements and potassium to their patients who must take diuretics. Hydrochlorothiazide is the diuretic most likely to deplete magnesium and potassium levels; newer-generation drugs such as indapamide cause fewer problems.

Diet Depletes Magnesium

Most people (including physicians) are not aware that the typical American diet is frequently short on magnesium. A century ago, magnesium and other minerals were widespread in the American diet. But current farming technology employs large amounts of inorganic fertilizers that are often low in magnesium. Overuse of phosphates, nitrates and ammonia drains much-needed magnesium from the soil. This combination of low-magnesium soil concentrations and the damaging impact of modern food processing results in decreased environmental availability of magnesium, and increased need for magnesium supplements.

Consider, too, the age of chemicals in which we live. Our bodies are enveloped by multiple chemical pollutants, such as aluminum, lead and iron, that interact with magnesium. By binding to and “using up” the body’s magnesium stores, these elements further increase our magnesium requirements.

Magnesium loss is also linked to a host of medical conditions, including alcohol abuse, prolonged use of antibiotics, anorexia nervosa (or any state of starvation or malnourishment), and excessive use of H-2 receptor antagonists such as Tagamet or Zantac.

Do You Need a Magnesium Supplement?

This can be difficult to answer. Although most hospitals and laboratories can measure serum levels of magnesium quite readily, the serum magnesium level has a very weak correlation with the level of magnesium in heart cells.

However, if your serum magnesium is low, then it’s highly likely that the magnesium level in your heart is low as well. Likewise, if your serum magnesium level is high, there is a reasonable chance that the magnesium level in your heart is probably adequate.

A more insidious problem occurs when the serum level falls within the normal range. You (and your doctor) might think all is well, but a normal serum magnesium does not necessarily indicate that the heart has a normal magnesium level in the cells.

Modern technology has yet to develop an ideal system for measuring magnesium. Although some tests include measuring levels in blood cells and skeletal muscle, these tests are technically difficult and very expensive.

Because of these pitfalls, I do not routinely order serum magnesium tests on my patients. I believe that since magnesium is safe, inexpensive and easy to use, it should be considered a mineral that deserves more use for chronic and acute cardiological problems.

Here’s When to Use a Magnesium Supplement

I believe that magnesium is so important for heart health that I made it part of my Awesome Foursome. If you’re in any of these situations, magnesium supplements are an absolute must.

  • You have suffered a heart attack or are at risk for heart attack;

  • You are prone to ventricular arrhythmia;

  • You have had or are planning open-heart surgery or a heart transplant;

  • You have congestive heart failure or cardiomyopathy;

  • You have high blood pressure;

  • You are taking diuretics long-term.

There is a great deal of evidence that magnesium, when administered according to specific protocols in appropriate dosages, can reduce the risk of death in patients who have suffered a heart attack. For example, when a person comes in with a heart attack, we give two grams (2,000 mg) intravenously over an hour.

In addition, magnesium supplements can prevent or reduce the severity of life-threatening ventricular arrhythmias that often occur after heart surgery, chiefly through its membrane-stabilizing effect and ability to maintain intracellular potassium, another crucial mineral for the heart. Some enlightened cardiac surgeons administer magnesium intravenously prior to bypass surgery.

Other research shows that a magnesium/selenium supplement combination can also be useful in treating ventricular arrhythmias.

Magnesium supplements are also effective in the treatment of patients with congestive heart failure and cardiomyopathy. Patients with very diseased hearts, especially those undergoing cardiac transplantation, typically have low levels of magnesium and coenzyme Q10 in their myocardial cells.

Perhaps the best indication for magnesium, with huge implications for large numbers of people, is in the treatment of high blood pressure. There is a direct relationship between low magnesium and high blood pressure. In addition, magnesium deficits are found in insulin-resistant individuals and particularly type 2 diabetics. Many diabetics are hypertensive as well.

Magnesium is endothelial-cell friendly, helping the lining of your arteries stay smooth and elastic. Over time, low magnesium levels may predispose the interior of your vessels to contract (go into spasm); eventually, high blood pressure can result. Magnesium can come to the rescue of contracted blood vessels and even reverse some of the damage.

Magnesium-Rich Foods

Foods rich in magnesium include whole grains, fish and seafood, leafy green vegetables, soy products, brown rice, bananas, apricots, seeds and nuts. The foods highest in magnesium include kelp, tofu, figs and pumpkin seeds.

I also recommend that you take a magnesium supplement if you aren’t already, particularly if you are on diuretics or have any of the cardiovascular conditions mentioned previously.

If such is the case, take 400–800 mg of magnesium each day as a supplement. Look for easily absorbable forms of magnesium such as magnesium orotate or magnesium citrate. Note: Excessive magnesium levels can be dangerous in patients with renal failure. If you have renal insufficiency or kidney failure, do not take a magnesium supplement unless prescribed and monitored by your physician.

If you are healthy, without heart, kidney or high blood pressure problems, you can get sufficient “insurance” levels of magnesium in a high-quality multivitamin/mineral supplement. Remember, magnesium works in concert with other nutrients, particularly B vitamins, CoQ10, and vitamin E.

All in all, a diet rich in fresh fruits and vegetables enhanced with targeted nutritional supplementation is your best bet to maintain optimum magnesium stores in the body and thus, protect you from a host of cardiac conditions. 

DISCLAIMER: The content of is offered on an informational basis only, and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified health provider before making any adjustment to a medication or treatment you are currently using, and/or starting any new medication or treatment. All recommendations are "generally informational" and not specifically applicable to any individual's medical problems, concerns and/or needs.

Enjoy What You've Just Read?

Get it delivered to your inbox! Signup for E-News and you'll get great content like you've just read along with other great tips and guides from Dr. Sinatra!

Enjoy What You've Just Read?

Get it delivered to your inbox! Signup for E-News and you'll get great content like you've just read along with other great tips and guides from Dr. Sinatra!