Institute of Medicine: Lowering daily sodium intake below 2,300 milligrams may do more harm than good
A report from the Institute of Medicine (IOM) suggests that lowering sodium below 2,300 milligrams per day may be harmful to your health.
While the organization, which is the health section of the non-profit organization the National Academy of Sciences, says that Americans are eating too much salt in their diets currently, their research has led them to conclude that lowering sodium too much may increase other adverse health risks.
"These new studies support previous findings that reducing sodium from very high intake levels to moderate levels improves health," committee chair Brian Strom, George S. Pepper Professor of Public Health and Preventive Medicine at the University of Pennsylvania Perelman School of Medicine, said in a press release. "But they also suggest that lowering sodium intake too much may actually increase a person's risk of some health problems."
Currently, the average American Adult consumes 3,400 milligrams or more of sodium a day or about 1.5 teaspoons of salt.
The current Dietary Guidelines for Americans suggests that people 14 to 50 should limit their salt intake to 2,300 milligrams daily. People 51 or older, African Americans and people with hypertension, diabetes or chronic kidney disease are recommended to keep their sodium levels below 1,500 milligrams in general. For reference, the American Heart Association (AHA) recommends that people stay below 1,500 milligrams per day to avoid heart disease and stroke risk, regardless of age, race or ethnicity.
High levels of sodium may be linked to one-third of Americans who have high blood pressure because the extra salt retains extra fluid in the body, making the heart work harder. High salt content has also been linked to increased risk for stroke, heart failure, osteoporosis, stomach cancer and kidney disease.
While the IOM committee found that higher levels of sodium consumption increased heart disease risk, they said studies on health outcomes are inconsistent and insufficient when it comes to whether lowering salt intake to below 2,300 can decrease the risk of heart disease, stroke or all-cause mortality.
In addition, low sodium intake was shown to have negative health affects for those with mid-to-late stage heart failure. There was also not that much evidence showing the effect of low salt consumption and other subgroups, including African Americans, people over 51 and those with health conditions like diabetes, kidney disease, hypertension or borderline hypertension.
The IOM called for more research into low sodium levels between 1,500 to 2,300 milligrams per day and the various health consequences for all people.
"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," Strom said. "Changes in diet are more complex than simply changing a single mineral. More research is needed to understand these pathways."
The Salt Institute, which represents the salt industry, said they were happy with the IOM's report that lowering sodium consumption may actually hurt some people.
"It is good to see that this report cautions against drastic sodium reduction efforts to get people to consume dangerously low levels of sodium of 1500 mg a day," Salt Institute vice president of science and research Morton Satin, said in a statement. "There is no scientific justification for population-wide sodium reduction to such low levels and the recognition by the IOM experts that such low levels may cause harm may help steer overzealous organizations away from reckless recommendations."
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However, the AHA called the IOM's conclusion "incomplete" because it did not highlight the fact that scientific evidence has shown that eating too much sodium can increase blood pressure.
"While the American Heart Association commends the IOM for taking on the challenging topic of sodium consumption, we disagree with key conclusions," AHA's CEO Nancy Brown said in a statement.
The non-profit organization Center for Science in the Public Interest (CSPI) added in a statement that they hope the IOM's findings won't stop the government, food industry, health professionals and consumers from pushing to lower sodium levels. As it stands, people eat way above the recommended 2,300 milligram limit, and the IOM themselves said in 2010 that more government action needs to be taken to lower sodium consumption.
CSPI published a study in JAMA Internal Medicine showing that packaged and restaurant food have not lowered their sodium content that much in recent years. The average sodium level in 402 random packaged foods only went down 3.5 percent between 2005 and 2011. Seventy-eight items found in chain restaurants actually increased salt content by 2.6 in the same period.
"At restaurants, you can get roughly 2,000 milligrams of sodium from just one burrito, a single-serve pizza, or an order of kung pao chicken, and at least 1,000 milligrams from a typical sandwich or burger," CSPI Nutrition Director Bonnie Liebman wrote. "As the IOM concluded in 2010 -- and as our new study published yesterday in JAMA Internal Medicine confirms--getting down to 2,300 will be nearly impossible until the government phases in reasonable limits on the sodium content of foods."
