The Institute of Medicine (IOM) recently issued a report assessing the scientific evidence behind government recommendations that adults in the general population reduce dietary sodium intake to less than 2,300 milligrams per day and that certain groups of people at a greater risk of developing cardiovascular disease (CVD) reduce their salt consumption to 1,500 mg per day. At the request of the Centers for Disease Control and Prevention, the IOM committee responsible for the report focused on new studies examining sodium’s direct effect on health outcomes as opposed to previous research that used high blood pressure as “a widely accepted biological predictor of risk for CVD and stroke.”

Based on this new research, the IOM report concludes that while the latest science still supports salt reduction recommendations for the general population, there is little or no new evidence to back the 1,500 mg/day recommendation for specific population subgroups, which include African Americans, people ages 51 and older, and those with certain medical conditions. In particular, the IOM committee reportedly found “no evidence for benefit and some evidence suggesting risk of adverse health outcomes associated with sodium intake levels in ranges approximately 1,500 to 2,300 mg/day among those with diabetes, kidney disease, or CVD.” Noting a lack of strong evidence either confirming or refuting that “these subgroups should be treated differently than the general U.S. population,” the report also lays out a research agenda meant to close “a number of data and methodological gaps” that currently “make comparisons across studies difficult.”

“These new studies support previous findings that reducing sodium from very high intake levels to moderate levels improves health,” said IOM Committee Chair Brian Strom in a May 14, 2013, press release. “But they also suggest that lowering sodium intake too much may actually increase a person’s risk of some health problems.”

Meanwhile, health and consumer groups have criticized the report for allegedly failing to take the larger picture into account. “While the American Heart Association [AHA] commends the IOM for taking on the challenging topic of sodium consumption, we disagree with key conclusions,” AHA CEO Nancy Brown was quoted as saying. “The report is missing a critical component – a comprehensive review of well-established evidence which links too much sodium to high blood pressure and heart disease.” See AHA Press Release, May 14, 2013.

The Center for Science in the Public Interest (CSPI) has since described the IOM report as fatally limited “by a narrow charge to examine only studies that looked at hard endpoints like heart attacks and strokes.” To this end, CSPI echoed IOM’s call for additional large-scale studies and urged health authorities to continue relying on the “mountain of evidence that higher sodium intakes raise blood pressure, and that high blood pressure raises the risk of cardiovascular disease.” See CSPI Press Release, May 14, 2013.