Sodium and Potassium Intake and Blood Pressure

There is increasing circumstantial evidence that the very high sodium diet combined with low potassium intake that most Western communities now eat may be, at least in part, responsible for the prevalence of high blood pressure. This circumstantial evidence combined with animal evidence has been considered sufficient in some countries to make a general recommendation to reduce sodium intake. If high sodium intake is an important cause of high blood pressure, it is not clear at the present time how it may do so. In this report, evidence is reviewed for one hypothesis suggesting an inherited defect in the kidney's ability to excrete sodium in patients who are going to develop essential hypertension, together with evidence for a raised concentration of an inhibitor of sodium transport. In patients with established hypertension, moderate restriction of sodium intake appears to lower blood pressure and moderate potassium supplementation to also lower blood pressure. While further evidence is required, particularly long-term studies, it would seem prudent to recommend to patients with essential hypertension or a strong family history of hypertension that they restrict dietary sodium intake moderately and increase dietary potassium intake by the consumption of more fruits and vegetables and, perhaps, the use of a potassium-based salt substitute. This regimen could obviate or reduce the need for drug treatment in some patients with mild to moderate hypertension. (Hypertension 5 (supp III): III-79-III-84, 1983)