Reducing Salt Intake for Prevention of Cardiovascular Disease—Times Are Changing

Abstract

The evidence relating blood pressure to salt intake in humans originates from population studies and randomized clinical trials of interventions on dietary salt intake. Estimates from meta-analyses of trials in normotensive subjects generally are similar to estimates derived from prospective population studies (+1.7 mm Hg increase in systolic blood pressure per 100-mmol increment in 24-hour urinary sodium). This estimate, however, does not translate into an increased risk of incident hypertension in subjects consuming a high salt diet. Prospective studies relating health outcomes to 24-hour urinary sodium excretion produced inconsistent results. Taken together, available evidence does not support the current recommendations of a generalized and indiscriminate reduction of salt intake at the population level, although the blood pressure-lowering effect of dietary sodium restriction might be of value in hypertensive patients.