Low Potassium Diets Related to High Blood Pressure

Low levels of potassium in the diet may be as important a contributor to high blood pressure as high levels of sodium—especially among African-Americans—researchers have found.

“Lowering salt or sodium in the diet to lower blood pressure is relatively well known, but more publicity on increasing dietary potassium is needed,” said lead author Susan Hedayati, MD, at the University of Texas Southwestern Medical Center in Dallas and the Dallas VA Medical Center.

Hedayati and her team studied whether low potassium intake, independent of sodium intake, was associated with increased blood pressure. They analyzed the fasting blood and first-void urine samples and blood pressure of more than 3300 multi-ethnic participants of the Dallas Heart Study, about half of whom were African-Americans.

Results showed that the lower the potassium in the urine, and thus in the diet, the higher the blood pressure. This relationship remained significant even after controlling for cardiovascular risk factors and the degree of kidney function. The effect of potassium on blood pressure was even stronger than the effect of sodium.

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Additional research led by Chou-Long Huang, MD, a co-author of this study, suggests that a specific gene, called WNK1, may be responsible for potassium’s effects on blood pressure. Hedayati, Huang, and their team are currently testing how low dietary potassium affects blood pressure through the activity of this gene.

“This study highlights the long-suspected beneficial effects of dietary potassium on blood pressure regulation,” said Levi Moshe, MD, of the University of Denver’s Division of Renal Diseases and Hypertension. “Now, studies to identify the mechanisms involved will be most interesting and important.”

The study “Dietary Potassium Deficiency Is Independently Associated with Increased Blood Pressure in a Multi-Ethnic Population-Based Cohort” was presented as part of a free communications session on “Clinical Aspects of Hypertension in Kidney Disease” at Renal Week.