The Heart-Healthy Mineral: How Magnesium Supports Cardiovascular Health

By Dr. Abdelwahab Arrazaghi, MD, FABIM, FRCPC

When we think about heart health, minerals don’t usually get the spotlight. Yet magnesium—a nutrient that quietly supports over 300 functions in the body—plays a surprisingly big role in keeping our cardiovascular system running smoothly. From regulating blood pressure to preventing dangerous heart rhythms, magnesium is one of those unsung heroes of heart protection.

Why Magnesium Matters for the Heart

Magnesium helps the heart in several key ways:

• Keeps blood vessels relaxed – It acts like a natural calcium blocker, reducing vascular resistance and helping lower blood pressure.

• Protects against irregular rhythms – Magnesium stabilizes heart cells, making dangerous arrhythmias less likely.

• Reduces clot risk – By limiting platelet stickiness, magnesium may help prevent blockages in the arteries.

• Combats inflammation – Low magnesium levels are linked to higher inflammation, which contributes to atherosclerosis.

In short: if your body is low on magnesium, your cardiovascular system feels the impact.

What the Research Says

Several large studies show just how powerful magnesium can be in protecting against heart attacks and other cardiovascular events:

• The ARIC Study found people with lower magnesium levels were more likely to suffer sudden cardiac death.

• The Nurses’ Health Study showed women with the highest magnesium intake had a reduced risk of fatal coronary heart disease.

• A meta-analysis of over 300,000 participants found higher dietary magnesium intake reduced stroke risk by 7% and heart failure by 9%.

Clearly, getting enough magnesium can make a real difference.

Supplements vs. Food: What’s Better?

For most people, boosting magnesium intake through food is the best place to start. Foods rich in magnesium include:

• Leafy greens like spinach and kale

• Nuts and seeds, especially almonds and pumpkin seeds

• Whole grains such as brown rice and oats

• Legumes like beans and lentils

• Fatty fish such as salmon and mackerel

If your diet falls short—or if you’re at higher risk for heart problems—supplementation may help. Research suggests that 300–500 mg per day of magnesium may lower blood pressure and improve vascular health.

However, when it comes to using magnesium during a heart attack, the evidence is mixed. Early trials suggested IV magnesium might reduce mortality, but larger studies didn’t confirm those results. Today, IV magnesium is typically reserved for patients with very low magnesium levels or certain arrhythmias.

Is Magnesium Safe?

For most healthy adults, magnesium is safe, though high doses may cause digestive side effects like diarrhea. People with kidney problems should be more cautious, as their bodies may not clear magnesium effectively, leading to dangerous levels.

Bottom Line

Magnesium isn’t a magic bullet, but it’s an essential part of a heart-healthy lifestyle. By eating magnesium-rich foods (and supplementing when appropriate), you may lower your risk of high blood pressure, arrhythmias, and even heart attacks.

As research continues, one thing is clear: this humble mineral deserves a bigger place in the conversation about cardiovascular health.