Can dietary sodium intake be modified by public policy?

Sodium chloride holds a unique position in the annals of human existence and science (1). For thousands of years, salt's high value has made it the foundation of a society, a currency of trade, and cause for wars. Over the past century, sodium chloride has been the subject of intense scientific research to understand its role in human physiology and its impact on health. The latter has focused primarily on salt's role in BP regulation, an issue fraught with controversy, as documented a decade ago (2) and still evident in the scientific literature (3,4). Since the first Surgeon General's Report Healthy People: Promotion and Disease Prevention published in 1979 (5), public health guidelines have recommended that adults consume less salt. This culminated in 2003 with the Institute of Medicine (IOM) Electrolyte DRI Committee targeting 2300 mg/d as the safe upper level of sodium in the diet (6). The 2005 Dietary Guidelines recommended this same level for healthy adults and 1500 mg/d for individuals at risk of hypertension (7). As increasingly more restrictive guidelines have been introduced over the past 30 yr, scientific research has continued to provide new insights regarding the effectiveness and safety of lowering sodium intake. Some, but certainly not all, of the newer data have supported the sodium guidelines (8,9), although the feasibility of their implementation remains in question. It has been assumed that if adults better understood how to reduce sodium in their diets and if more low-sodium foods were available, more individuals would be able to achieve these levels. Public health experts throughout the world have devised strategies targeting greater compliance with the lower sodium recommendations. In the United States (US), a special IOM committee has recently been charged to formulate such strategies (10). Great Britain initiated an intense …