Michelle Fay Cortez / Bloomberg News

Salt is at the center of a battle among government agencies and health advisers who can’t agree on what is too much or too little for a healthy diet.

Four months after an Institute of Medicine report said reducing salt to the lowest recommended level doesn’t improve health and may harm it, the U.S. Centers for Disease Control and Prevention said they disagree. In an article published Monday in the American Journal of Hypertension, the CDC and New York City health officials said getting Americans to eat less salt remains a key objective with the potential to save thousands of lives.

The IOM report stirred controversy after doctors and the media suggested the findings meant national efforts to cut salt consumption were unnecessary and potentially dangerous. The CDC, which commissioned the IOM report, the New York City Department of Health and others are now writing in to reiterate their commitment to lowering sodium consumption.

At issue is the question of how low consumers should go when it comes to salt. The U.S. Department of Health and Human Services recommends no more than 2,300 milligrams a day in general, and 1,500 milligrams a day for anyone with hypertension; blacks; or people older than 51. The high-risk subgroup accounts for roughly half of the U.S. population.

The CDC is committed to trying to get the U.S. population to those levels, down from the current average consumption of 3,400 milligrams, wrote CDC Director Thomas Frieden and his colleagues.

That goal may be dangerous, said Michael Alderman, the editor-in-chief of the American Journal of Hypertension, who pulled together eight reports and commentary that explored all angles of the debate. The relationship between heart disease and sodium “has a ‘J’ shape,” with both low and high levels creating risk, he said.

It looks like there is a broad range of sodium intake that’s compatible with excellent health. Getting too much or too little is a problem. More research is needed to clearly identify those levels, he said.

“Thirty years of looking hard to find evidence that people eating less than the recommended levels of sodium are better off, and not having found it, may give people pause to think maybe it isn’t there,” he said.