Excessive dietary sodium raises blood pressure, whereas a high potassium diet has the opposite effect. The underlying mechanisms are moderated by sex and involve multiple organs and tissues. How do high potassium-induced alternations in kidney function lower blood pressure, and how do those mechanisms differ between men and women? To answer these questions, a duo of researchers at the University of Waterloo conducted computer simulations to simulate whole-body fluid and electrolyte homeostasis, and the effects of sodium and potassium intake on blood pressure.
Melissa Stadt & Anita Layton suggest increasing the ratio of dietary potassium to sodium intake may be more effective for lowering blood pressure than simply reducing sodium intake. Image credit: Melissa Stadt & Anita Layton, doi: 10.1152/ajprenal.00222.2024.
High blood pressure affects over 30% of adults globally. It’s 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,” said Professor Anita Layton, corresponding author of the study.
“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 — substances that help the body send electrical signals to contract muscles, affect the amount of water in your 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,” said Melissa Stadt, first 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.”
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.
The model also identifies how sex differences affect the relationship between potassium and blood pressure.
The scientists 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.
“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,” they said.
The team’s paper was published in March 2025 in the American Journal of Physiology-Renal Physiology.
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Melissa Stadt & Anita T. Layton. Modulation of blood pressure by dietary potassium and sodium: sex differences and modeling analysis. American Journal of Physiology-Renal Physiology, published online March 3, 2025; doi: 10.1152/ajprenal.00222.2024
