Salt is all right, researchers say

Doctors have long been telling us that salt is poison, but American scientists are challenging this decades-old conventional wisdom that we should watch our salt.  

In an article published in the latest issue of the Clinical Journal of the American Society of Nephrology a team of University of California-Davis nutrition researchers maintain that humans naturally regulate their sodium intake. In the article David McCarron, an adjunct UC-Davis nutrition professor, says that the controversial conclusion is backed by sound data.  

The study finds that the human body makes sure sodium levels remain within a certain range at all times, similar to bodily functions that are homeostatically maintained, such as body temperature. 

"Our sodium intake is regulated by the brain, and your brain won't let you go very far outside of that boundary," McCarron said. "You may eat that whole bag of chips, but it just means that as you sit down you'll unconsciously go toward foods that are lower in sodium." 

After aggregating sodium intake data from 20,000 adults in 32 countries, researchers found the adult range of sodium intake to be narrow: between 2,700 to 4,900 milligrams of sodium a day. Because the data encompasses many different dietary cultures, researchers conclude that humans, on their own, maintain a "normal" range of salt intake. 

"There looks to be a pretty darn strict lower and upper limit on sodium levels," McCarron says. "Just because our food supply is filled with sodium doesn't mean it's ending up in our bodies." 

Furthermore, the authors concluded that the US Food and Drug Administration guidelines are too stringent. Current FDA dietary guidelines recommend no more than 2,300 mg of sodium be eaten per day, which is 14.8 percent lower than the study's observed lower limit.  

The study has angered nutrition policy advocates, with Michael Jacobson with the Center for Science in the Public Interest warning that to follow the report’s conclusions would be a disservice to the people.

“There are tribes out there where people eat just one gram of salt a day and it’s perfectly all right,” he says, adding that Europeans had long stopped eating too much salt and were pretty much happy about it…