Magnesium’s Role in Heart Health

February 27, 2021

Magnesium’s Role in Heart Health

Multiple studies reveal magnesium’s cardio-protective effects. One found that those with the highest magnesium levels had a 44% lower risk of heart failure. More than half of all Americans have low magnesium levels.

MAGNESIUM is a hard-working mineral. It helps 300 enzymes perform vital functions throughout the body. Magnesium’s benefits range from building bone to producing energy and synthesizing proteins.But it doesn’t stop there. It also helps prevent an array of cardiovascular disorders. Dietary surveys have shown deficient intake of magnesium is epidemic in the United States. Data from the National Health and Nutrition Examination Survey show that 48% of Americans of all ages have intake below the estimated average requirement.1,2 Inadequate magnesium levels have been linked with an increased risk for cardiovascular disease, including stroke, coronary heart disease, heart failure, arrhythmias, and death.3,4

Higher blood levels of magnesium are associated with a lower cardiovascular disease risk.4

Hidden Danger of Low Magnesium

Magnesium is a mineral found in many foods, including leafy vegetables, whole grains, beans, nuts, yogurt, and fish. But it’s difficult to get and absorb enough from dietary sources alone. Approximately 64% of all men and 67% of women in the U.S. have inadequate dietary intake of magnesium. Among those above age 71, roughly 81% of men and 82% of women have inadequate dietary intake of magnesium.5,6 That’s a serious problem. Magnesium is involved in critical metabolic functions.7 This means that myriad bodily systems and functions depend on adequate magnesium and suffer when deficiency occurs.Adequate magnesium is especially important for healthy and efficient function of heart muscle and blood vessels. Recent human studies confirm a strong association between low magnesium levels and higher heart disease risk.5

Correcting Arrhythmias

People with low magnesium levels are more susceptible to developing arrhythmias, potentially fatal disorders of heart rhythm.Arrhythmias involve abnormal conduction of the electrical impulses that govern heartbeat, causing a beat that is irregular, too fast, or too slow.Atrial fibrillation, an irregular and often rapid heartbeat, is the leading cardiac cause of strokes. This happens when a fluttering atrial chamber in the heart causes a clot (thrombus) to form that travels up a carotid artery and blocks blood flow to a portion of the brain. This is called an ischemic stroke; the term “ischemia” means “no blood flow”. One large study found that people with the lowest blood magnesium levels were approximately 50% more likely to develop atrial fibrillation than those with thehighest levels. This association occurs even in people without cardiovascular disease.10 Magnesium intake has been shown to correct low-magnesium-related arrhythmias.11,12 For example, intravenous (IV) magnesium is routinely used before many heart surgeries that are known to induce postoperative arrhythmias.13-17 Oral magnesium is often recommended for those with arrhythmias and low magnesium levels.

Fighting Endothelial Dysfunction

Endothelial dysfunction occurs when the cells lining the inside walls of blood vessels (the endothelium) lose normal, healthy function.18 This promotes the formation of artery-blocking plaque, resulting in atherosclerosis, a narrowing of the arteries that restricts blood flow.19,20 In cultured human endothelial cells, magnesium deficiency activates the protein complex NF-kB (nuclear factor kappa B), a major facilitator of atherosclerosis.21 In a randomized, controlled human trial, women aged 40-65, all of whom had high blood pressure and were on diuretic therapy, took either a placebo or 600mg of magnesium daily.22 After six months, those taking magnesium had significantly improved endothelial function, which led to reductions in blood pressure and increased blood vessel dilation (widening). Systolic blood pressure fell, on average, from 144 mmHg to 134 mmHg, and diastolic blood pressure decreased from 88 mmHg to 81 mmHg. In addition, the thickness of the carotid artery—a measure of unhealthy arterial thickening—rose in placebo patients but remained unchanged in magnesium- treated patients.22 Thickening of the carotid artery indicates progression of atherosclerosis.

Preventing Heart Failure

Heart failure occurs when the heart doesn’t pump enough blood to meet the body’s needs. Currently there are about 6.2 million adults in the U.S. with heart failure.23 In one study of 22 patients with symptomatic chronic heart failure, an 800 mg/day dose of magnesium for three months produced a significant increase in arterial compliance (a measure of how well an artery can relax and contract in response to blood flow).24 This suggests improved endothelial function and improved ability of the arteries to deliver oxygen-rich blood to target organs. Blood levels of magnesium are also strongly associated with cardiovascular risk. An epidemiological study of 3,523 men aged 60-79, with no prior history of cardiovascular disease, demonstrated that risk for heart failure declined steadily with rising magnesium levels.25


The Cardiovascular Benefits of Magnesium

  • Magnesium is a mineral needed for at least 300 enzymes throughout the body to perform their metabolic functions.
  • Human studies confirm a strong association between low magnesium levels and higher risks of cardiovascular diseases.
  • Almost half of Americans of all ages are below the estimated average requirement for magnesium.
  • Human studies demonstrate that taking oral magnesium helps ward off cardiovascular problems and supports overall heart health.


The U.S. Food and Drug Administration has advised doctors to check patients’ magnesium levels before prescribing medications known as proton-pump inhibitors or PPIs.38 Proton-pump inhibitors like Prevacid®, Prilosec®, and Nexium® are taken for the treatment of heartburn, also known as gastroesophageal reflux disease (GERD). They are also used to treat peptic ulcer disease. A scientific review of 35 studies from 2010 to 2018 suggests that, in some people, taking proton-pump inhibitors causes low magnesium levels.39 These low levels are associated with increased risk of cardiac arrhythmias, and with one often-deadly type in particular, torsade de pointes (or TdP), which can result in sudden cardiac arrest.39 Talk to a doctor about whether to check your magnesium levels before taking proton- pump inhibitors. Those with the highest magnesium blood levels had a 44% lower risk of heart failure than those with the lowest levels. Higher magnesium levels in this study were associated with reduced markers of inflammation and endothelial dysfunction.25

Reducing High Blood Pressure

Excess body weight, lack of physical activity, diabetes, and normal aging increase the chances of developing high blood pressure.26,27 A link between magnesium and hypertension has been shown in several human clinical trials.28-30 These studies show that the lower the magnesium level in patients, the higher the systolic blood pressure. One meta-analysis of trials that enrolled more than 2,000 subjects, found that supplementation with magnesium reduced systolic and diastolic blood pressure in hypertensive patients.31 Those who fail to achieve optimal systolic blood pressure under 120 to 130 mm Hg should consider an anti-hypertension drug like telmisartan.

Lowering Heart Attack and Stroke Risk

Human studies also demonstrate an association between low magnesium and increased risk of heart attack and stroke.6,32-35 In one analysis of human trials that included a whopping 241,378 participants, researchers found that every 100 mg of magnesium in the daily diet was associated with an 8% lower risk of stroke.34 A similar association was found in a later published meta-analysis.35

Combating Coronary Artery Disease

Coronary artery disease occurs when the arteries to the heart become narrowed due to atherosclerotic plaque. This reduces blood flow and significantly boosts the risk of a heart attack. It is the leading cause of death in men and women in the U.S.36 Magnesium intake has been shown to improve heart function and exercise tolerance in patients with coronary artery disease. In one study, scientists gave 53 men with coronary artery disease 365 mg of oral magnesium citrate twice daily. After six months, they had improved oxygen utilization during exercise and greater pumping action in their left ventricle, the heart’s main pumping chamber.37 These effects indicate that magnesium improved blood flow and oxygen delivery in these patients.


The mineral magnesium is vital for heart health. More than 80% of people over age 71 have inadequate dietary intake of magnesium, placing them at risk for serious cardiovascular events. Cardiovascular disease, including stroke, coronary heart disease, heart failure, arrhythmias, and even death, has been associated with inadequate magnesium levels. Low-cost magnesium supplements offer an easy solution to replenish this essential mineral.


By Michael Downey.


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