05 Mar 2015 Another way salt is a vital nutrient: new research
Too much salt can lead to heart disease, according to the common medical, but now often-disputed, wisdom. However, there may be a healthy side to salt that hasn’t been appreciated — until now.
Latest research — which, the scientists stress, is still in its early stages — hints that there may be some benefits to salt that have gone unnoticed. Salt, it seems, may be an ancient way for the body to protect itself against bacteria.
Reporting in the journal Cell Metabolism, Jonathan Jantsch, from the University of Regensburg in Germany, says that salt may be an effective way to ward off microbes. In a series of studies using both mice and human cells, he and his colleagues found that levels of sodium go up around an infection site, and that without salt, bacteria tend to flourish and grow better.
The discovery came about by accident, after Jens Titze, the study’s senior author, noticed that mice who had been bitten by their cage mates showed higher levels of sodium in their skin than those who were wound-free. Jantsch decided to find out whether the salt had something to do with the infection-fighting functions of the immune system.
He and his team conducted a series of experiments in which they subjected mouse and human cells to high levels of sodium chloride, and watched the immune cells activate. They also fed mice diets that were low and high in sodium, and then infected them with Leishmania major. The mice fed the higher amounts of sodium showed stronger immune responses to the wounds, and cleared their infections faster than the mice eating less salt. In fact, Jantsch speculates that certain skin cells may transport sodium preferentially to sites where bacterial populations are high in order to create another barrier preventing the microbes from entering deeper into the body.
That opens the possibility that salt may be an unrecognised contributor to the immune system, and possibly a remnant from the days before antibiotics, when mammals, including humans, needed some allies in the fight against microbes. After all, salt has been used for centuries to preserve food from spoiling in bacteria’s presence, so it makes sense that evolutionarily, sodium might have also been co-opted by the body in a similar way.
“I really think salt is an unappreciated factor of immunity,” says Jantsch…..
TIME: Read the full article
Journal Reference: http://www.cell.com/cell-metabolism/abstract/S1550-4131%2815%2900055-8