A surprising new report questions public health efforts to get Americans to sharply cut back on salt, saying it's not clear whether eating super-low levels is worth the struggle.
Make no mistake: Most Americans eat way too much salt, not just from salt shakers but because of sodium hidden inside processed foods and restaurant meals. Tuesday's report stresses that, overall, the nation needs to ease back on the sodium for better heart health.
But there's no good evidence that eating very low levels — below the 2,300 milligrams a day that the government recommends for most people — offers benefits even though national guidelines urge that certain high-risk patients do just that, the Institute of Medicine concluded.
Also, there are some hints, albeit from studies with serious flaws, that eating the lowest levels might actually harm certain people — those who are being aggressively treated for serious heart failure, the report added.
The prestigious group, which advises the government about health, urged more and better research to settle the best target range.
"We're not saying we shouldn't be lowering excessive salt intake," said Dr. Brian Strom of the University of Pennsylvania, who led the IOM committee. But below 2,300 mg a day, "there is simply a lack of data that shows it is beneficial."
The average American consumes more than 3,400 mg of sodium a day, equivalent to 1 ½ teaspoons. Current U.S. dietary guidelines say most people should limit that to 2,300 mg a day, while certain people — those older than 50, African-Americans, and people with high blood pressure, diabetes or chronic kidney disease — should aim for just 1,500 mg.
Tuesday's report sparked an immediate outcry from health organizations that have long battled to lower the nation's salt consumption.
The American Heart Association said it stood by its own recommendations, stricter than the government's, that everyone eat no more than 1,500 mg of sodium a day. Studies make clear that eating less sodium helps lower blood pressure, and lower blood pressure in turn leads to less heart disease, said heart association spokesman Dr. Elliott Antman, a cardiologist at Boston's Brigham and Women's Hospital.
"We're sticking where we have the most solid evidence," Antman said.
What to study is key to the debate: The IOM committee was asked to examine whether eating less salt directly affects longer-term outcomes such as heart attacks and death. That's harder to prove, especially since the panel stressed many of the studies it reviewed had quality problems. Among those problems, Antman said, was including some patients too sick for diet to matter.