years of age and 70 years or older were set at 1,300 and 1,200 mg per day, respectively. A UL was established for sodium based on evidence showing associations between excessive sodium intake and risk of high blood pressure and consequent risk of CVD, stroke, and mortality (see Chapter 3 for a detailed discussion). Evidence from intervention studies showed no threshold in the dose-response curve of the relationship between sodium intake level and blood pressure, and therefore a no-observed adverse effect level (NOAEL) could not be established. Instead, a UL of 2,300 mg per day for males and females 14 years and above was established based on the lowest observed adverse effect level (LOAEL) from the dose–response evidence for blood pressure. For some population subgroups, namely older individuals, African Americans, and those with hypertension, diabetes, or CKD, the report suggested the UL should be lower than 2,300 mg/day although a defined level was not determined (see IOM, 2005, pp. 387-394, for more detailed information).
The Dietary Guidelines for Americans (DGA) are the basis for federal nutrition policy and nutrition programs. The goals of the DGA have evolved since the first DGA were published in 1980, reflecting changes in the science of nutrition and understanding of the role of nutrition in health. Every 5 years the DGA are revised, drawing from a technical review of evidence by a panel of experts, the Dietary Guidelines Advisory Committee (DGAC). In 2005, the DGAC concluded that the general adult population reduce sodium intake to less than 2,300 mg of sodium per day (HHS and USDA, 2005). The committee further concluded that individuals with hypertension, African Americans, and middle-aged and older adults (51 years of age and older) would benefit from reducing their sodium intake even further (HHS and USDA, 2005).
Because these latter groups together now comprise a majority of U.S. adults, the 2010 DGAC technical report concluded that a goal for sodium intake reduction should be 1,500 mg per day for the general population (HHS and USDA, 2010a). The Dietary Guidelines for Americans, 2010 (HHS and USDA, 2010b), the federal nutrition policy document, recommended retaining the goal that the general adult population should reduce consumption to less than 2,300 mg per day, but only that individuals 51 years of age and older, African Americans, and those with hypertension, diabetes, and CKD should reduce intake to 1,500 mg per day.
As with the DRI report (IOM, 2005), the rationale for the DGAC (HHS and USDA, 2010b) conclusion is grounded in evidence for a relationship between sodium intake and blood pressure as a surrogate marker of disease, and supported by additional evidence that decreasing blood pressure is associated with decreased risk of adverse health outcomes, particularly stroke and ischemic heart disease. Although the scientific community continues to debate the use of biomarkers in general and surrogate indicators