Potassium-rich foods may lower blood pressure more effectively than cutting salt, study finds

Chiquita bananas on display at a grocery store in Bainbridge, Ohio. (AP / Amy Sancetta)

New research from the University of Waterloo (UW) suggests that increasing the ratio of dietary potassium to sodium may be more effective at lowering blood pressure than simply reducing salt intake.

High blood pressure affects more than 30 per cent of adults worldwide and is a major contributor to coronary heart disease and stroke. It can also lead to other serious conditions such as chronic kidney disease, heart failure, arrhythmias and dementia.

“Usually, when we have high blood pressure, we are advised to eat less salt,” said Anita Layton, professor of Applied Mathematics, Computer Science, Pharmacy. “Our research suggests that adding more potassium-rich foods to your diet, such as bananas and broccoli, might have a greater positive impact on your blood pressure than just cutting sodium.”

Electrolyte balance critical to blood pressure regulation: researchers

According to researchers, both potassium and sodium are electrolytes—substances that help transmit electrical signals in the body and regulate muscle contractions and water balance.

Melissa Stadt, a PhD candidate in Waterloo’s Department of Applied Mathematics and the lead author of the study, noted that the modern diet may be at odds with how human bodies have evolved to process these elements.

“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,” Stadt said. “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 ones.”

Mathematical model reveals sex-based differences

The UW research team developed a mathematical model to explore how the body responds to varying potassium-to-sodium ratios and how these responses differ between sexes.

The model showed that men are more likely than pre-menopausal women to develop high blood pressure but also more likely to benefit from a higher potassium-to-sodium ratio in the diet.

The study emphasizes the importance of not just cutting sodium but increasing potassium intake to help balance electrolyte levels and support healthy blood pressure, according to Layton and Stadt.

Foods rich in potassium include:

• Bananas
• Broccoli
• Sweet potatoes
• Spinach
• Avocados
• Beans and lentils
• Yogurt
• Salmon