Magnesium: A Nutrient Your Heart LOVES!

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kathryn matthews | The Nourished Epicurean

What nutrient is absolutely essential for a healthy heart?

If you guessed “chocolate”….close, but no cigar! It’s the mineral magnesium.

Vital for heart health, magnesium:

1.   Prevents muscle spasms of the heart blood vessels…which can lead to a heart attack.

2.   Prevents muscle spasms of the peripheral blood vessels…which can lead to high blood pressure.

3.   Prevents calcium build-up in cholesterol plaque in arteries…which leads to clogged arteries. (1)

Magnesium is necessary for the proper functioning of 700-800 enzyme systems in the body. Magnesium helps create energy. As our body’s fourth most abundant mineral, magnesium plays a vital role in (2):

§  Regulating blood pressure, heart rate and blood sugar levels

§  Maintaining nerve function §  Keeping muscles relaxed

§  Alleviating stress, anxiety and depression

Keep in mind: While magnesium is a potent mineral that confers many essential health benefits, it works synergistically with other important nutrients that support heart health, including B vitamins, vitamin D3 with K2 and omega 3 fatty acids.

Magnesium and Your Heart

Magnesium is a mineral and a key electrolyte. Adequate magnesium is positively associated with heart health. Conversely, magnesium deficiency is implicated in many chronic health conditions, including heart disease. To this point…a study, published in Atherosclerosis, found that people who had low serum magnesium levels were more than twice as likely to die of heart disease. Low serum magnesium levels were also associated with an increased risk of death from all causes (3).

Heart conditions where magnesium can be significantly beneficial include:

–Arteriosclerosis / Atherosclerosis. Arteriosclerosis occurs when your blood vessels (carrying oxygen and nutrients from the heart to the rest of the body) become thick and stuff, which can restrict blood flow from your heart to your organs and tissues (4).

Atherosclerosis. This (preventable) condition is a specific type of arteriosclerosis caused by fatty plaque build-up in and on your artery walls. Plaque build-up causes your arteries to narrow, reducing the supply of oxygen-rich blood to vital organs in the body, including the heart (5). If/when the plaque bursts, this leads to a blood clot (6). The damaged tissue starts an inflammatory process that attracts “bad” cholesterol and calcium, creating scar tissue (7).

In the Framingham Heart Health Study, researchers found that magnesium exerted a protective effect in strokes and fatal coronary heart disease. In this study, higher magnesium intake—through diet and supplementation—was associated with less arterial calcification (hardening of the arteries). (8)

–Arterial stiffness. Arterial stiffness occurs when the walls of large arteries, especially the aorta, lose elasticity over time (9). Studies suggest that increased arterial stiffness can precede hypertension as well as heart disease (10). Arterial stiffness also increases the risk of developing heart disease in Type 2 diabetics.

The good news? Supplementing with magnesium can help reduce arterial stiffness, a marker for heart disease.

In a 2015 clinical trial, 52 overweight and slightly obese adults—50% men, 50% women (post-menopausal only), aged 45 to 70—were selected. The participants were given 350 mg magnesium citrate per day in 3 divided doses. After six months, participants experienced a significant reduction in arterial stiffness (11).

–High Blood Pressure.

High blood pressure (hypertension) is another risk factor for heart disease.

Hypertension is either primary or secondary. Primary hypertension occurs in 90 to 95 percent of those diagnosed with hypertension. Secondary hypertension, usually indicative of another disease (e.g., atherosclerotic renal artery stenosis, renal failure, or hypothyroidism), occurs in 5 to 10 percent of all hypertensive patients. (12). Causes of primary hypertension can include dehydration, high cholesterol, insulin resistance, obesity, high alcohol intake, poor diet, smoking, stress, a sedentary lifestyle and excessive consumption of processed salt / table salt (13, 14).

However, according to Dr. Carolyn Dean, a medical doctor, naturopath and author of The Magnesium Miracle, one major cause of hypertension that is overlooked is magnesium deficiency.

A meta-analysis, published in the journal Hypertension suggests a causal link between low magnesium and high blood pressure.  Researchers found that taking 300 mg per day of supplemental magnesium for one month was helpful in significantly reducing blood pressure (15).

–Heart Attack (Myocardial Infarction).

A heart attack is caused by a blockage that stops blood flow to the heart (16). A heart attack refers to the death of heart muscle tissue due to loss of blood supply and is technically considered a “circulation” problem (17). A blood clot typically causes this blockage—and can be sudden and complete.

How does this happen? Coronary arteries transport oxygen-rich blood to the heart. However, plaque build-up causes coronary arteries to become narrow. If the plaque ruptures, a blood clot forms, and part of the blood clot may break away and clog one of the coronary arteries. This creates a blockage that starves the heart muscle of blood (and oxygen), triggering a heart attack (18).

In the event of a heart attack, studies suggest that intravenous magnesium can have beneficial effects if administered 1) before any other drugs and 2) immediately after onset of a heart attack (19, 20).

According to Dean, administering magnesium ASAP after a heart attack can “improve the aftermath of a heart attack by preventing rhythm problems, increasing blood flow to the heart by dilating blood vessels, protecting the damaged heart muscle against calcium overload, improving heart muscle function, breaking down any blood clots breaking arteries and reducing free radical damage.”(21)

–Cardiac Arrest.

Cardiac arrest happens when your heart suddenly and unexpectedly stops beating because the heart’s pumping function is “arrested” or stopped (22). To be clear, a heart attack is NOT the same as cardiac arrest. However, having a heart attack can cause cardiac arrest.

Studies have found that “hypomagnesemia”, a term that refers to an abnormally low level of magnesium in the blood (<0.65 mmol/L), is a known risk factor for cardiac arrest (23).

Beyond Heart Health…

In addition to heart health, magnesium is a key mineral and electrolyte for our overall health, hormonal balance, energy, mood and vitality. Unfortunately, most of us—some experts estimate up to 90% of Americans—are deficient in magnesium (24).

Including me.  I had low magnesium…

In the 2010s, I was in what most people would consider peak physical shape. At the time, I was an intense exerciser, working out about two to three hours a day, 5 to 6 days a week. As a runner, I logged about 35-40 miles a week and strength-trained most days as well. I looked healthy and fit, yet I struggled with what felt like alarming symptoms: muscle cramps and spasms, random muscle twitches, foot pain, chronic tendonitis, intense anxiety, a racing heart, and heart palpitations that prevented—or disrupted—my sleep.  And, although I was in top running form, I had high blood pressure!  My blood pressure ranged from 130 to 140 (systolic) / 90 to 99 (diastolic)…and, once as high as 160/100. One nutritionist suspected an electrolyte imbalance, but she focused on potassium and calcium—not magnesium. Drinking potassium-rich V-8 and tomato juice and taking calcium supplements did absolutely NOTHING for me.  At the time, I did not realize that magnesium, which is also an electrolyte, can be quickly depleted by overtraining. Three years later, I discovered magnesium and, for me, personally, it was a life-changing supplement.

What Causes a Magnesium Deficiency?

Our modern convenience-based lifestyle depletes magnesium. We lose magnesium when we (25):

      • Eat processed foods.
      • Consume a high sugar diet.
      • Eat refined or simple carbohydrates.
      • Regularly consume caffeine: coffee, tea, soda or energy drinks.
      • Eat zero or too little leafy greens.
      • Experience chronic stress: physical, emotional, mental.
      • Trauma
      • Sweat excessively (from physical exertion).
      • Overtrain or over-exercise.
      • Take synthetic hormones, like birth control pills or conventional HRT (Hormone Replacement Therapy).
      • Sleep too few hours; sleep off-circadian rhythm; or, have poor quality sleep.
      • Drink alcohol.
      • Use marijuana. *Whether you use marijuana recreationally or therapeutically (to treat a medical condition), it drains magnesium stores.
      • Use prescription drugs—the vast majority of which deplete magnesium—including, but not limited to: antibiotics, bronchodilators (for asthma), diuretics, corticosteroids (oral and inhaled), proton pump inhibitors (for acid reflux), antacids, blood pressure medications, immunosuppressants and statins (26).

What does a magnesium deficiency feel like?

Magnesium is involved in multiple pathways throughout the brain and body. Consequently, a long list of potential symptoms and behaviors can indicate magnesium deficiency, including, but not limited to the following (27):

Physical Symptoms

      • Muscle cramps or spasms
      • Muscle twitching
      • Tremors of the hands
      • Menstrual pain / cramps
      • PMS (Pre-Menstrual Syndrome)
      • Constipation
      • Digestive issues: undigested fat in stool, IBS, Crohn’s, diarrhea, etc.
      • Food cravings (especially carbohydrates, chocolate, salt and junk food)
      • Headaches / Migraines
      • Heart: arrhythmia, heart palpitations
      • High blood pressure
      • Low calcium and/or low potassium
      • Osteoporosis
      • Insomnia

Mood Imbalances

      • Anger
      • Apathy
      • Anxiety
      • Depression
      • Irritability

What are food sources of magnesium?

      • Seafood.  Kelp, dulse
      • Dark leafy greens and cruciferous vegetables. Spinach, Swiss chard, collard greens, dandelion greens, broccoli, and cauliflower
      • Fish.  Halibut, mackerel
      • Nuts.  Almonds, cashews, Brazil nuts, pecans
      • Seeds.  Pumpkin seeds, sunflower seeds, sesame seeds
      • Gluten-free pseudocereal “super seeds”. Buckwheat, quinoa
      • Fruit.  Dried figs, apricots, dates, blackberries

Dark chocolate is often touted as being high in magnesium, and it is—in its raw, unsweetened form—as in raw cacao nibs, raw cacao powder or unsweetened cocoa powder. A high quality, organic dark chocolate bar (85% cacao or higher) is also an excellent source of magnesium. My go-to favorite is 95% cacao; my second favorite is 85% cacao.

Unfortunately, it is virtually impossible to get enough magnesium from food alone.

Modern farming practices, such as the use of commercial fertilizers, have dramatically depleted our soil of nutrients over the last century; this was noted in a U.S. Senate document as far back as 1936 (28)!

The following are direct excerpts from U.S. Senate Document 264, dated June 5th, 1936:


“The alarming fact is that foods (fruits, vegetables and grains) now being raised on millions of acres of land that no longer contain enough of certain minerals are starving us—no matter how much of them we eat. No man of today can eat enough fruits and vegetables to supply his system with the minerals he requires for perfect health because his stomach isn’t big enough to hold them.

It is bad news to learn from our leading authorities that 99% of the American people are deficient in these minerals, and that a marked deficiency in any one of the more important minerals actually results in disease. Any upset of the balance, any considerable lack or one or another element, however microscopic the body requirement may be, and we sicken, suffer, shorten our lives.”


Most of us also lead fast-paced, stressful lives that include processed foods, caffeine, sugar, alcohol, too little sleep, inadequate hydration and/or taking medications, all of which conspire to keep magnesium levels low. Since discovering magnesium a decade ago, I have been supplementing with several different forms—even though I eat organic foods, filter my water, cook virtually all of my own meals and do not take medications. I have hypothyroidism and adrenal dysfunction, which makes me even more sensitive and susceptible to stress of all kinds. I test my Magnesium RBC regularly, every 3 to 6 months, as magnesium is key for hormonal balance.

Are YOU deficient in magnesium?

Always test. Don’t guess. Taking a magnesium supplement willy-nilly without knowing your baseline level is like trying to lose weight without bothering to weigh yourself at the outset of a weight loss journey. Magnesium is stored mostly in your bones, soft tissues, and cells. Less than 1% of total magnesium is stored in your blood. This is why getting a standard serum (blood) test for magnesium (which doctors typically ordered if you request bloodwork for magnesium) is a highly inaccurate measure of total magnesium in the body.

If you want an accurate evaluation of your magnesium status, ask specifically for a Magnesium RBC (Red Blood Cell) test, which measures the magnesium level in red blood cells. You can ask your doctor for this test or order your own test here (click on Nutrient Panel; a menu will drop down).

The higher end of the lab reference range is optimal.  Within a typical lab reference range of 4.2 to 6.8 for Magnesium RBC, the optimal level is 6.0 to 6.5 (29).

Supplementing with Magnesium

How much you take is very individual; it depends on how depleted you are. Overall, most Americans are below baseline intake. Two out of three Americans do NOT consume the recommended daily allowance (RDA) for magnesium: 320 mg for women and 420 mg for men (30). Dean also points out: At best, your body is actually only absorbing about half of what is taken in (31).

There are different types of magnesium. Magnesium citrate powder is a popular form. Magnesium oxide, the form that doctors will often recommend to patients, is the last absorbable form of magnesium (about 4%).

Personally, I use the following types of magnesium, which are highly absorbable and beneficial for increasing intracellular levels of magnesium:

Transdermal magnesium oil

Magnesium glycinate

Slow-release magnesium malate + B Vitamin co-factors

Supplementing with magnesium is fairly safe. There are, however, 4 exceptions who should NOT supplement with magnesium: Those who have 1) kidney failure, 2) myasthenia gravis, 3) excessively slow heart rate or 4) bowel obstruction (32).

In The Magnesium Miracle, Dean notes that, even when taken at high doses, an oral magnesium, like magnesium citrate, has no side effects, except loose stools. This laxative-like effect is the body’s fail-safe mechanism of releasing any excess magnesium that it does not need. It is also a sign to either reduce the overall dosage or to take smaller amounts in divided doses.

That said, if you are taking prescription medications, check with your doctor first before supplementing with magnesium.

CONTINUE READING:  6 Easy Ways to Get More Magnesium





1, 2, 7, 13, 19, 21, 25, 27, 29, 31, 32  The Magnesium Miracle by Carolyn Dean. 2nd Edition. Aug. 15, 2017.

3  Reffelmann T, Ittermann T, Dörr M, Völzke H, Reinthaler M, Petersmann A, Felix SB. Low serum magnesium concentrations predict cardiovascular and all-cause mortality. Atherosclerosis. 2011 Nov;219(1):280-4. doi: 10.1016/j.atherosclerosis.2011.05.038. Epub 2011 Jun 12. PMID: 21703623.

4, 6

5  NIH. Artherosclerosis.

8  Hruby A, O’Donnell CJ, Jacques PF, Meigs JB, Hoffmann U, McKeown NM. Magnesium intake is inversely associated with coronary artery calcification: the Framingham Heart Study. JACC Cardiovasc Imaging. 2014 Jan;7(1):59-69. doi: 10.1016/j.jcmg.2013.10.006. Epub 2013 Nov 27. PMID: 24290571; PMCID: PMC3957229.

9, 10  Oh, Y.S. Arterial stiffness and hypertension. Clin Hypertens 24, 17 (2018).

11  Peter J Joris, Jogchum Plat, Stephan JL Bakker, Ronald P Mensink, Long-term magnesium supplementation improves arterial stiffness in overweight and obese adults: results of a randomized, double-blind, placebo-controlled intervention trial, The American Journal of Clinical Nutrition, Volume 103, Issue 5, May 2016, Pages 1260–1266.

12  Charles L, Triscott J, Dobbs B. Secondary Hypertension: Discovering the Underlying Cause. Am Fam Physician. 2017 Oct 1;96(7):453-461.

14  Carretero, O.A. and Oparil, S. Essential Hypertension. Circulation. Vol. 101, Issue 3, 25 Jan. 2000; Pages 329-335

15  Zhang X, Li Y, Del Gobbo LC, Rosanoff A, Wang J, Zhang W, Song Y. Effects of Magnesium Supplementation on Blood Pressure: A Meta-Analysis of Randomized Double-Blind Placebo-Controlled Trials. Hypertension. 2016 Aug;68(2):324-33.

16, 17  American Heart Association. Cardiac Arrest.

18  American Heart Association. Acute Coronary Syndrome.

19  Antman, Elliot M. Magnesium in Acute MI. Circulation. Vol. 92, Issue 9, 1 Nov. 1995. Pages 2367-2372.

22  NIH. What Is a Heart Attack?

23  Del Gobbo LC, Imamura F, Wu JH, de Oliveira Otto MC, Chiuve SE, Mozaffarian D. Circulating and dietary magnesium and risk of cardiovascular disease: a systematic review and meta-analysis of prospective studies. Am J Clin Nutr. 2013 Jul; 98 (1):160-73.

24  Epsom Salt Council. Oct. 23, 2019

26  Drug Muggers: Which Medications Are Robbing Your Body of Essential Nutrients by Suzy Cohen, RPh

28  U.S. Senate Document 264. 74th Congress, 2nd Session, June 5, 1936.

 30  King DE, Mainous AG 3rd, Geesey ME, Woolson RF. Dietary magnesium and C-reactive protein levels. J Am Coll Nutr. 2005 Jun;24(3):166-71.

Hi, I’m Kathryn Matthews. As a Board Certified Functional Health Coach, I help clients reclaim their energy, vitality and well-being. I want you to feel empowered about taking charge of YOUR health! To learn more, see About Kathryn.

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