Reducing sodium (salt) in the diet has been recommended to lower blood pressure and the risk of heart disease. However, in a new review article, University of Southern California researchers found that increasing dietary potassium is as important to improving the risk factors for cardiovascular and kidney disease as limiting dietary sodium. The article is published ahead of print in the American Journal of Physiology—Endocrinology and Metabolism.
The research team reviewed more than 70 studies related to dietary approaches to regulating high blood pressure and found that the interaction of sodium and potassium is integral to maintaining healthy blood pressure levels. The ratio of sodium to potassium excreted as urine is an indication of how much of these minerals is consumed. When dietary potassium intake is elevated, the kidneys—composed of millions of small tubes working together—shift fluid to the area near the end of the tubes where potassium secretes into the urine. This shift reduces the amount of sodium and water that's reabsorbed into the body. In this way, high potassium diet signals the body to reduce the amount of sodium that is retained. This circular pattern regulates the levels of both minerals in the body, which in turn helps lower blood pressure. Higher intake and excretion of potassium has also been found to slow the progression of kidney and heart disease.
In addition to analyzing data about the sodium-potassium ratio and its relationship to chronic disease, the research team explored strategies to educate the public about the importance of potassium for blood pressure control and heart health. Suggested policies include:
• Requiring manufacturers to print potassium content on Nutrition Facts labels,
• Promoting low-cost and easily available sources of potassium (milk, dried beans, potatoes, bananas) and
• Encouraging families to cook healthy, plant-based meals together.
"Consuming [an abundance] of [potassium] is a good strategy since our physiology evolved and was optimized to deal with high [potassium] low [sodium] intake, often referred to a Paleolithic diet," wrote the research team. In other words, the human body functions best with a balance of the two nutrients.