Bananas Over Salt? New Research Rewrites Blood Pressure Advice

What if controlling your blood pressure was more about boosting potassium than cutting salt?

New research shows that shifting the balance between these two electrolytes – especially increasing potassium-rich foods like bananas and broccoli – may be a more effective strategy. With a nod to our evolutionary roots and modern diets, scientists used mathematical modeling to reveal how this ratio affects men and women differently, offering a fresh path forward in heart health.

Potassium vs. Sodium for Blood Pressure

New research from the University of Waterloo suggests that increasing the amount of potassium in your diet – especially in relation to sodium – may be more effective at lowering blood pressure than simply reducing salt intake.

High blood pressure affects more than 30 percent of adults worldwide. It’s a major risk factor for heart disease and stroke, and it’s also linked to chronic kidney disease, heart failure, irregular heart rhythms, and even dementia.

Rethinking the Salt Reduction Advice

“Usually, when we have high blood pressure, we are advised to eat less salt,” said Anita Layton, professor of Applied Mathematics, Computer Science, Pharmacy and Biology at the University of Waterloo and the Canada 150 Research Chair in Mathematical Biology and Medicine.

“Our research suggests that adding more potassium-rich foods to your diet, such as bananas or broccoli, might have a greater positive impact on your blood pressure than just cutting sodium.”

The Role of Electrolytes in the Body

Potassium and sodium are both electrolytes – minerals that help the body transmit electrical signals, regulate muscle function, and manage fluid balance. The balance between these two minerals plays a key role in maintaining healthy blood pressure.

“Early humans ate lots of fruits and vegetables, and as a result, our body’s regulatory systems may have evolved to work best with a high potassium, low sodium diet,” said Melissa Stadt, a PhD candidate in Waterloo’s Department of Applied Mathematics and the lead author of the study.

The Industrialized Diet Problem

“Today, western diets tend to be much higher in sodium and lower in potassium. That may explain why high blood pressure is found mainly in industrialized societies, not in isolated societies.”

While previous research found that increasing potassium intake can help control blood pressure, the researchers developed a mathematical model that successfully identifies how the ratio of potassium to sodium impacts the body.

How Sex Differences Affect Blood Pressure

The model also identifies how sex differences affect the relationship between potassium and blood pressure. The study found that men develop high blood pressure more easily than pre-menopausal women, but men are also more likely to respond positively to an increased ratio of potassium to sodium.

The researchers emphasize that mathematical models like the one used in this study allow these kinds of experiments to identify how different factors impact the body quickly, cheaply, and ethically.

Reference: “Modulation of blood pressure by dietary potassium and sodium: sex differences and modeling analysis” by Melissa Stadt and Anita T. Layton, 3 March 2025, American Journal of Physiology-Renal Physiology.