A new report from the Institute of Medicine shows that, while high levels of sodium intake should be lowered, too little sodium intake could also be harmful.
“These new studies support previous findings that reducing sodium from very high intake levels to moderate levels improves health,” said Brian Strom, a professor of public health and preventive medicine at the University of Pennsylvania. “But they also suggest that lowering sodium intake too much may actually increase a person’s risk of some health problems.”
The studies reiterated that there is evidence that high sodium intake is associated with heart disease risk. However, it also found that studies showing that sodium intake below 2,300 mg per day lowers the risk of heart disease and stroke are too "inconsistent" to recommend extremely lowered sodium intake. Lower sodium intake was, in fact, found to be linked to "adverse health effects" for those with mid- to late-stage heart failure.
Researchers stated that the average U.S. adult consumes 3,400 mg (one and one-half teaspoons) or more of sodium per day. Current recommendations on sodium intake suggest that adults ages 14 to 50 lower their sodium intake to 2,300 mg per day, and that adults over 50 and those with hypertension, diabetes, and chronic kidney disease lower their intake to 1,500 mg per day.
Though the report calls current recommendations into question, it does not recommend an intake range for sodium. It also suggests that sodium could affect heart disease in ways other than blood pressure.
“These studies make clear that looking at sodium’s effects on blood pressure is not enough to determine dietary sodium’s ultimate impact on health,” said Strom. “Changes in diet are more complex than simply changing a single mineral. More research is needed to understand these pathways.”