Dietary sodium and health: more than just blood pressure

Abstract

Sodium is essential for cellular homeostasis and physiological function. Excess dietary sodium has been linked to elevations in blood pressure (BP). Salt sensitivity of BP varies widely, but certain subgroups tend to be more salt sensitive. The mechanisms underlying sodium-induced increases in BP are not completely understood but may involve alterations in renal function, fluid volume, fluid-regulatory hormones, the vasculature, cardiac function, and the autonomic nervous system. Recent pre-clinical and clinical data support that even in the absence of an increase in BP, excess dietary sodium can adversely affect target organs, including the blood vessels, heart, kidneys, and brain. In this review, the investigators review these issues and the epidemiological research relating dietary sodium to BP and cardiovascular health outcomes, addressing recent controversies. They also provide information and strategies for reducing dietary sodium.

Keywords: dietary sodium chloride; hypertension; kidney; sodium-restricted diet.

Central Illustration. Dietary Salt and Health: Mechanisms Mediating Dietary Salt-Induced Alterations in BP

High dietary sodium can potentially exert its influence through various mechanisms to cause an increase in BP through alterations in cardiac output and total peripheral resistance. The change (Δ) in BP varies considerably, even within a given population (as depicted in the distribution). AT₁ = angiotensin II receptor, type1; BP = blood pressure.

Figure 1. BP Independent Effects of High Dietary Sodium

High dietary sodium can cause target organ damage and may have direct effects on the brain, heart, kidneys, and vasculature. These effects can be independent of changes in BP.