Scientists say salt may guard against infection

NASHVILLE, March 3 (UPI) -- A new study suggests salt accumulates in the skin of mice and humans as a biological strategy for warding off infections.

The revelatory study, published this week in the journal Cell Metabolism, offers a new perspective on the mineral mostly fingered as an instigator of nutritional and health-related problems like hypertension.

The new research, conducted by scientists from Vanderbilt University and a number of universities in Germany, showed that salt may facilitate a natural barrier to microbial invasion.

Researchers came to their hypothesis after using a magnetic resonance imaging (MRI) technique to measure salt accumulation in and around skin infections in six patients. Physicians found high concentrations of salt in the skin of patients' infected legs. Healthy legs boasted no discernible concentrations of the mineral.

After treating the patients with antibiotics, the salt accumulation disappeared along with the infection.

To follow up their research, scientists tested a high-salt diet on mice battling infections on the bottoms of their feet (footpads). The diet enabled an increased concentration of salt at the source of infection and allowed the mice to rid themselves of the infection more quickly than those that did not receive a high-salt diet.

But researchers said their findings don't translate to a recommendation for increased salt intake.

"I think that the most important finding here is that tissues can accumulate massive amounts of sodium locally to boost immune responses where ever needed," lead author Jens Titze said. "This mostly happens totally independent of the diet."

The natural infection-fighting function of salt accumulation may be largely unnecessary, given the widespread use of antibiotics.

The results may also help explain why elderly patients show high concentrations of salt, as salt stores may grow as the aging body deals with more and more instances of inflammation, in response to the maladies of old age like heart disease and cancer.