New research prioritizes higher potassium-to-salt ratio to reduce blood pressure

Researchers at the University of Waterloo, Canada, encourage that increasing the ratio of dietary potassium to sodium intake is more effective for lowering blood pressure than simply reducing sodium intake.

High blood pressure affects over 30% of adults globally, the researchers stress. The condition is the leading cause of coronary heart disease and stroke and may also lead to other afflictions like chronic kidney disease, heart failure, irregular heartbeats, and dementia.

“Usually, when we have high blood pressure, we are advised to eat less salt,” says 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.”

Potassium and sodium are both electrolytes. These substances help the body send electrical signals to contract muscles, affect the amount of water in the body, and perform other essential functions.

“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,” says Melissa Stadt, a Ph.D. candidate in Waterloo’s Department of Applied Mathematics and the lead author of the study.

“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.”

Finding the right ratio of potassium to salt

The study findings are particularly timely following last month’s formal recognition from the World Health Organization that replacing table or sea salt with potassium salt is a safe and effective way to reduce sodium intake.

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

The model also identifies how sex differences affect the relationship between potassium and blood pressure. The study found that men develop high blood pressure easier than premenopausal women, but notes that 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.

The study, “Modulation of blood pressure by dietary potassium and sodium: sex differences and modeling analysis,” was recently published in the American Journal of Physiology-Renal Physiology.

Aside from contributing to high blood pressure and cardiovascular disease, scientific research associates high sodium with reduced kidney function and an increased risk of stomach cancer.