Salt and Hypertension: Is Salt Dietary Reduction Worth the Effort?

Abstract

In numerous epidemiologic, clinical, and experimental studies, dietary sodium intake has been linked to blood pressure, and a reduction in dietary salt intake has been documented to lower blood pressure. In young subjects, salt intake has a programming effect in that blood pressure remains elevated even after a high salt intake has been reduced. Elderly subjects, African Americans, and obese patients are more sensitive to the blood pressure-lowering effects of a decreased salt intake. Depending on the baseline blood pressure and degree of salt intake reduction, systolic blood pressure can be lowered by 4 to 8 mm Hg. A greater decrease in blood pressure is achieved when a reduced salt intake is combined with other lifestyle interventions, such as adherence to Dietary Approaches to Stop Hypertension. A high salt intake has been shown to increase not only blood pressure but also the risk of stroke, left ventricular hypertrophy, and proteinuria. Adverse effects associated with salt intake reduction, unless excessive, seem to be minimal. However, data linking a decreased salt intake to a decrease in morbidity and mortality in hypertensive patients are not unanimous. Dietary salt intake reduction can delay or prevent the incidence of antihypertensive therapy, can facilitate blood pressure reduction in hypertensive patients receiving medical therapy, and may represent a simple cost-saving mediator to reduce cardiovascular morbidity and mortality.