Dietary Potassium in Cardiovascular Prevention: Nutritional and Clinical Implications

A dietary pattern characterized by high sodium and low potassium intake contributes unequivocally to a rise in blood pressure and eventually to hypertension. The purpose of this review is to discuss here the complex relationship among dietary potassium, potassium homeostasis and blood pressure regulation. Potassium is the major intracellular cation in the body. The fine regulation of its balance rely on a close interplay between extrarenal and renal mechanisms aimed to maintain the large concentration gradient between intracellular and extracellular potassium. Apparently, the homeostatic control of potassium balance is less effective in preventing subtle or major potassium deficiencies induced by chronic subnormal potassium intake. The hypothesis that low potassium intake may cause a rise in blood pressure derives from epidemiological surveys showing an inverse relationship between individual blood pressure levels and 24-hour urinary potassium excretion. The results of the clinical trials confirmed that an increase of potassium intake lowers blood pressure in patients with hypertension and, to a lesser extent, in normotensive subjects. Furthermore, there is promising evidence that an increase in potassium intake (namely from fruit and vegetables) is associated with a reduction in stroke mortality. We conclude that increasing dietary potassium through an increase in the consumption of fruit and vegetables is an important public health target.