Should You Take Magnesium?

What Really Makes a Diet “Healthy”? Let’s Talk Minerals

When we think of healthy eating, we often zero in on macronutrients: proteins, carbs, and fats. Or maybe we focus on vitamins and minerals—the tiny-but-mighty micronutrients that power everything from our metabolism to immune function.

But are certain nutrients more essential than others? Is protein king? Does vitamin D deserve its superstar status? Honestly, it’s hard to pin down. Nutrition is complex, and ranking nutrients can feel like choosing a favorite child.

That said, a recent study caught our attention for an interesting reason: it zeroed in on minerals and their relationship to longevity—especially in people with cardiovascular disease (CVD).

Let’s break it down.

Inside the Study: Minerals and Mortality

Researchers in China dove into data from a group of U.S. adults with cardiovascular disease who had participated in NHANES (the National Health and Nutrition Examination Survey). They focused on nine essential minerals:

• Iron

• Copper

• Selenium

• Zinc

• Magnesium

• Potassium

• Phosphorus

• Calcium

• Sodium

These minerals fall into two broad categories:

• Transition metals (iron, copper, selenium, zinc): These help support vital cellular functions. But too much—like excess iron—can be harmful, promoting inflammation and plaque buildup in arteries.

• Electrolytes (magnesium, potassium, calcium, sodium, phosphorus): These regulate hydration, nerve signaling, and pH balance, among other things. Each one also has unique roles—like calcium’s role in bone strength and phosphorus’s role in energy production.

To assess mineral intake, researchers used dietary recall interviews. Participants reported what they ate, and professionals estimated the mineral content. The researchers then linked this data with mortality records from the National Death Index.

Important Study Limitations

Before we get to the findings, here are a few caveats:

1. The dietary data represents a snapshot in time—not a long-term view of their eating habits.

2. BMI was recorded at the start, but there’s no follow-up on weight changes.

3. Actual blood or tissue mineral levels weren’t measured—just estimated through diet.

The Standout Finding: Magnesium

One result stood out: People with the highest magnesium intake were 37% less likely to die from any cause compared to those with the lowest intake.

None of the other minerals showed a strong link to mortality after adjusting for factors like BMI, smoking, income, and physical activity.

But things got weird when researchers looked at BMI categories:

• Among those with a BMI under 25, five minerals were linked to lower death risk: magnesium, potassium, phosphorus, sodium, and copper.

• In the overweight category, only four minerals showed a benefit: magnesium, potassium, calcium, and iron.

• For those with obesity, only sodium was linked to a reduced risk of death.

That raises more questions than answers. Why would sodium help the lightest and heaviest individuals, but not the ones in between? And why would mineral benefits change based on BMI at all?

We don’t know. But there’s some context that helps make sense of at least part of the story.

Two Big Takeaways

1. Magnesium Might Just Be a Marker of a Healthy Diet

Those who consumed the most magnesium also ate more of every other mineral. That’s because magnesium-rich foods—like leafy greens, legumes, whole grains, and nuts—tend to be nutrient-packed across the board.

They also lived healthier lifestyles overall: more physically active, less likely to smoke, and slightly lower BMIs (though the difference wasn’t statistically significant).

Another surprise? They ate 40% more calories than others in the study—and still had lower mortality. That suggests that energy intake alone isn’t the issue—nutrient density matters.

2. Magnesium Supplements ≠ the Same Benefits

Dietary magnesium is consistently linked to lower mortality. Supplements? Not so much.

A 2021 review found that while food-based magnesium intake was tied to longer life, magnesium supplements didn’t show the same effect. That doesn’t mean supplements are useless—they may help with things like sleep or blood sugar—but they’re not a silver bullet for longevity.

Bottom Line

Magnesium seems to play a key role in overall health—especially for people with CVD. But the real magic isn’t in the mineral itself; it’s in the diet that delivers it.

If you’re eating a wide variety of whole, nutrient-rich foods, you're not just getting magnesium—you’re getting an entire orchestra of health-supporting nutrients working in harmony.

And that’s what truly makes a healthy diet… well, healthy.