The Mineral That Can Lower Blood Pressure and Stroke Risk (And It’s Not Magnesium)

If you’ve ever sat in your doctor’s office, watched the blood pressure cuff tighten, and heard the familiar advice to "cut down on salt," you’re not alone. Most of us respond by banishing the salt shaker, reading labels obsessively, and giving up our favorite salty snacks—only to watch the numbers barely budge.

It turns out we might be missing half the picture. While sodium raises blood pressure, there’s another mineral that acts in the opposite direction and doesn't get nearly enough attention: potassium.

Potassium helps your kidneys flush out excess sodium and relaxes the walls of your blood vessels. Yet, according to a review of nutritional surveys across 52 countries (PubMed), the global average intake is only about 2,250 mg per day - and a mere 14% of people hit the World Health Organization's target of over 3,500 mg daily.

Here is what the research says, and how you can boost your intake safely starting this week.

1. Cutting Salt Is Only Half the Equation

Think of sodium and potassium as partners. Whenever you cut back on something salty, try adding something rich in potassium instead - like a piece of fruit instead of an afternoon salty snack, or legumes in a salad or soup.

In a landmark study published in the NEJM (PubMed), researchers tracked over 10,700 adults using rigorous 24-hour urine collections. They found that every extra 1,000 mg of daily sodium was linked to an 18% higher risk of cardiovascular events, like heart attacks or strokes - while every extra 1,000 mg of potassium was linked to an 18% lower risk.

2. How Much Can It Lower Blood Pressure?

A review of 22 controlled trials published in the BMJ (PubMed) found that increasing potassium intake lowered systolic ("top number") blood pressure by about 3.5 mmHg on average. In trials where intake reached 3,500 to 4,700 mg a day, that drop reached roughly 7 mmHg (though primarily in people with pre-existing high blood pressure).

Furthermore, the large British EPIC-Norfolk study involving nearly 25,000 people (PubMed) showed that the protective link between potassium and lower blood pressure was especially strong in women with high-sodium diets.

What to do: If you have high blood pressure, try measuring it at home - at the same time each day while seated - for a week before making dietary changes, and again after four to six weeks to see if it's working for you. Bring your log to your doctor.

3. The Link to Lower Stroke Risk

A review of 11 cohort studies following nearly 247,000 participants for up to 19 years (PubMed) found that consuming 1,640 mg more potassium per day was associated with a 21% lower risk of stroke. That is roughly the amount found in just one cup of cooked lentils and a medium baked potato with its skin.

What to do: Try adding one serving of legumes to your daily routine. A single cup of cooked lentils or white beans provides about 700 to 1,000 mg of potassium. Swap regular fries for a whole baked potato or sweet potato.

4. The Simple Switch in Your Salt Shaker

Some of the strongest evidence comes from a massive 2021 NEJM trial (PubMed) involving nearly 21,000 elderly individuals in China with high blood pressure or a history of stroke. Villages that switched to a salt substitute made of 75% regular salt and 25% potassium chloride saw 14% fewer strokes, 13% fewer cardiovascular events, and 12% fewer deaths over nearly five years.

A subsequent WHO review and recommendation in 2025 (WHO Guidelines) suggests that adults using salt consider potassium-enriched salt substitutes - though note that this recommendation is conditional and does not apply to pregnant women, children, or those with kidney disease.

5. Bananas Aren’t the Ultimate Champion (And Cooking Matters)

When people think of potassium, they instantly think of bananas. But according to the USDA Food Data Center (USDA FDC), a medium banana contains about 420 mg of potassium, compared to:

• 1 cup of cooked lentils: ~730 mg

• 1 medium baked potato (with skin): ~900 mg

• 1 cup of cooked white beans: ~1,000 mg

Plus, potassium is water-soluble. Boiling chopped potatoes in water can leach out up to 50% of their potassium (and up to 75% if grated) (PubMed).

What to do: Bake, roast, or boil your potatoes whole with their skins on. If you make homemade vegetable soup, drink the broth too - that’s where a lot of the leaked potassium goes!

A Quick Word on Medications and Magnesium

If you take blood pressure medications, you need to be mindful. Diuretics (like thiazides) can lower blood potassium levels (PubMed), while other common medications (like ACE inhibitors, ARBs, and spironolactone) can raise them. Always talk to your doctor before changing your salt habits or trying supplements.

And what about magnesium? While magnesium doesn't replace potassium, a deficiency in magnesium can actually worsen potassium loss through the kidneys (PubMed). Eating magnesium-rich foods like nuts, seeds, leafy greens, and legumes (which are also packed with potassium) helps cover both bases naturally.

The Takeaway

When it comes to blood pressure, everyone talks about salt, but potassium is the forgotten half of the equation. Start small: add a serving of legumes to your plate today, swap your fries for a baked potato, or chat with your doctor about whether a potassium-enriched salt substitute is right for you. Track your numbers over the next few weeks, and let the data guide your progress!