Science 101

What Is Magnesium?

Understand the powerful health benefits, and confusion, around this element.


“All life on this planet is due to magnesium,” said Burton M. Altura, PhD, a professor of Physiology and Pharmacology at SUNY Downstate. It’s not an overstatement. The earth’s mantle is composed primarily of silicon, oxygen and — you guessed it — magnesium. Green plants, so vital to all life on Earth, need magnesium to conduct photosynthesis, the process by which plants convert water and carbon dioxide into oxygen and carbohydrates, releasing oxygen to our air. Magnesium is, in a word, fundamental.

Why We Need Magnesium

Human life follows suit, biologically speaking. Joan Salge Blake, EdD, RD, a Clinical Associate Professor at Boston University’s Sargent College of Health and Rehabilitation Sciences, said, “you need magnesium for protein synthesis, DNA synthesis, nerve impulse conduction, muscle contraction, heartbeat. It’s just one of these things we need in our body.”

Muscles, nerves, blood vessels, bones, DNA, RNA — all rely on magnesium. Common knowledge attributes “more than 300” enzyme systems that are dependent on magnesium, but Altura put that number at over 500. “It regulates every pathway we need,” he said.

Most Americans, however, do not typically intake enough magnesium. According to the What We Eat In America surveys, run by the U.S. Department of Agriculture and the U.S. Department of Health and Human Services, our magnesium intake levels are low across the board. That does not mean that most Americans are magnesium deficient — the kidneys limit urinary excretion of magnesium, retaining healthy levels of magnesium even if recent intake is sub-par. And both Altura and Blake were not particularly concerned about magnesium deficiency in the US, except in cases such as chronic alcoholism or acute health conditions.

Yet the benefits of magnesium, as well as the downsides of low magnesium, definitely inspire a considered and consistent dietary intake.

The most notable impact of low magnesium is high blood pressure, with a direct link to stroke and heart attacks. Altura, along with his research partner and wife, Bella T. Altura, PhD, a now-retired research professor of Physiology and Pharmacology at SUNY Downstate, has been pioneering this research for half a century. Starting in 1980, in an article in Science, they published findings on dogs with specialty diets containing high, medium, and low magnesium levels. They found that basal tension in the arteries increased with low magnesium and decreased with high magnesium. That initial publication was followed by a 1984 Science article linking magnesium and hypertension in rats. In the 35 years since the body of research has grown and continues to expand on the initial findings — including research specific to humans. 

In the late 1990s, the Alturas identified that 98% of stroke patients admitted to three nearby hospitals were deficient in ionized magnesium. “When you lower the magnesium levels, these vessels go into spasm,” Altura noted.

Most healthy individuals are not at risk — but the implications of this research are helpful for treating patients and populations suffering from chronic diseases. Low levels of magnesium are also linked to aging, and identifying low dietary intake and improving magnesium levels as we age can lead to healthier aging and the prevention of age-related diseases.

How to Get Your Magnesium

For healthy individuals, diet is the best way to manage proper magnesium levels. And this includes water. Most people receive at least 10% of their daily intake of magnesium from drinking water. For magnesium intake purposes, hard water (water containing minerals like magnesium and calcium) is better than soft water (water only containing sodium). Soft water does have aesthetic benefits, like fewer mineral deposits on glassware, but it also strips tap water of its magnesium, reducing the daily intake of its drinkers.

It’s difficult to control the magnesium levels in your drinking water, but diet is an area you have plenty of control. Blake, whose focus is on research-based nutrition education, recited the advice of the USDA’s MyPlate, with a bit more nuance: “eat a diet that’s plant-forward,  fruit, vegetables and whole grains, with lean dairy, lean protein, specifically fish and leaner cuts of meat and poultry.”

Foods high in magnesium include legumes, nuts, seeds, whole grains and leafy vegetables. Other foods include almonds, walnuts, peanuts and cashews as well as potatoes, avocados, collard greens and spinach. “It’s like the old Popeye story,” Altura said. “Eat your spinach because you get strength.”

Omega oils and magnesium also enjoy a very complementary relationship. In both bony fish and dark chocolate, there is a high percentage of Omega-3s and magnesium. It’s a winning combination — and a good argument for a holistic approach to a healthy diet. “Magnesium by itself is not going to be the super nutrient,” Blake noted. “It needs to be a part of a well-balanced diet.”

As for magnesium dietary supplements? Both Altura and Blake supported dietary intake. The intestines process foods better than supplements. Plus, a well-rounded diet brings many other nutrients and vitamins to the system (although Altura did concede that both he and his wife take magnesium supplements).

Consuming too much magnesium from your diet is not a health risk. Just as the kidneys will retain magnesium when intake is low, they also will release excess magnesium if needed. There is a higher possibility of consuming too much magnesium if taking supplements, so follow a doctor or nutritionists recommended amount. 

For those that feel their magnesium intake may be low, the first piece of advice Blake offered was to consult a professional. “You should never self-diagnose if you’re low in any essential nutrients,” she said. And, know that the majority of the population is at very low risk. Symptoms of low magnesium include loss of appetite, fatigue, and nausea. In healthy people, this tends to only occur with magnesium loss from diarrhea and vomiting. Populations at higher risk of magnesium deficiency include elderly people and people suffering from gastrointestinal diseases, type 2 diabetes, and chronic alcoholism.

“It’s rare that you’ll be deficient from one nutrient,” Blake said. “If you’re malnourished, you’re going to be deficient in magnesium and a boatload of other things.” 

For healthy people concerned with maintaining a proper amount of magnesium, the focus should be on consuming a diverse, healthy diet. Magnesium is an element that is core to the plants, animals and all living cells on this planet; if you give the body the raw materials, it knows exactly what to do.

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