A spokeswoman for the American Heart Association declined to comment on the letter sent by the Salt Institute. In January, however, the group laid out the science behind lowering salt intake in an advisory statement published in the group's journal, Circulation.
Two key components of improving cardiovascular health are population-wide lowering of blood pressure below 120/80 and reducing sodium chloride intake below 1,500 mg per day, according to the statement. The group said there is ample evidence -- more than 50 randomized clinical trials -- that link reducing sodium to lowering blood pressure. Aside from affecting blood pressure, consuming too much sodium affects the heart, kidneys and blood vessels, the AHA said.
The Salt Institute doesn't dispute salt's connection to high blood pressure.
"We're not saying that reduction of blood pressure is bad, we're just staying that using salt as the main lifestyle reduction strategy to obtain that reduction is a dangerous strategy," Morton Satin, the vice president of science and research at the Salt Institute told MedPage Today.
In addition, the Salt Institute argues that in an effort to cut down on salt, Americans are actually consuming more calories. When people eat a lot of "low salt" packaged foods they still have a salt craving and will eat more calories to satisfy that craving, Satin said.
As a result, actual sodium consumption hasn't changed at all over time, despite the government recommendations, Satin said.
He said he would like the government to sponsor a large-scale clinical trial to see how a reduction in salt intake affects overall health, not just blood pressure levels.
"Are we better off or worse off for salt reduction?" he said. "Before anybody tries to change the American diet around one simple item -- which is salt -- we really ought to have a trial. We are in territory that is uncharted. No society in the world that eats that low a level of salt."
A spokeswoman for HHS defended the dietary guidelines.
"The Dietary Guidelines for Americans provides science-based advice to promote health and reduce the risk of major chronic diseases through diet and physical activity," the spokeswoman said.
The Salt Institute also filed a Freedom of Information Act request with the federal government requesting all documents related to the sodium-reduction decision from the 2010 federal nutrition guidelines.