Blood pressure, cardiovascular outcomes and sodium intake, a critical review of the evidence

Abstract

Consideration of the role of NaCl (salt) in the pathogenesis and treatment of essential hypertension is one of the overriding research themes both in experimental and clinical medicine. 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-mmHg 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‑h 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. The public should be properly educated about the pros and cons of a decrease in sodium intake, in particular if they are healthy.