Sodium Intake and Health: What Should We Recommend Based on the Current Evidence?

Abstract

Several health organizations recommend low sodium intake (below 2.3 g/day, 5.8 g/day of salt) for entire populations, on the premise that lowering of sodium intake, irrespective of its level of intake, will lower blood pressure and, in turn, will result in a lower incidence of cardiovascular disease. These guidelines were developed without effective interventions to achieve long term sodium intakes at low levels in free-living individuals and without high-quality evidence that low sodium intake reduces cardiovascular events (compared with average levels of intake). In this review, we examine whether advice to consume low amounts of sodium is supported by robust evidence. We contend that current evidence indicates that most people around the world consume a moderate range of dietary sodium (3 to 5 g/day), that this level of intake is associated with the lowest risk of cardiovascular disease and mortality, and that the risk of adverse health outcomes increases when sodium intakes exceeds 5 g/day or is below 3 g/day. While the current evidence has limitations, it is reasonable, based upon prospective cohort studies, to suggest a mean target of below 5 g/day in populations, while awaiting the results of large randomized controlled trials of sodium reduction on cardiovascular disease and death.

Keywords: blood pressure; cardiovascular disease; mortality; population health; renin–angiotensin–aldosterone system; salt; sodium.

Figure 1

Conceptual diagram of health risk by sodium intake levels based on the current evidence. The lowest risk range (i.e., “sweet spot”) for sodium intake is at ~3 to 5 g/day, with both lower and higher levels of intake associated with higher risk of cardiovascular disease or death. The Dietary Guidelines for Americans (DGA) recommendation for sodium corresponds with a higher risk of adverse health outcomes.