The recommendations to reduce dietary sodium and, to a lesser extent, increase dietary potassium have been included in many guidelines for the treatment of hypertension and prevention of cardiovascular disease. However, recent studies have raised questions about potential adverse effects associated with low sodium intake on important health outcomes, including cardiovascular disease and death. This study (one part of the Prospective Urban Rural Epidemiology [PURE] trial) is one of three published in the New England Journal of Medicine that examine the health effects of sodium intake and highlight the need to collect high-quality evidence on both the risks and benefits of low-sodium diets. The findings from this study and a companion study examining cardiovascular events provide evidence that both high and low levels of sodium excretion may be associated with an increased risk of death and cardiovascular-disease outcomes and that increasing the urinary potassium excretion counterbalances the adverse effect of high sodium excretion. These findings require confirmation in a randomised, controlled outcome trial to compare reduced sodium intake with usual diet, but in the absence of such data, an editorial suggests that the current trial findings argue against reduction in dietary sodium as an isolated public health recommendation.