Dietary salt could defend the body against invading microbes, according to a new study.
Overconsumption of salt has long been known to increase risk of heart disease and stroke however, researchers in Germany say it warded off skin-parasites from infecting mice.
"Up to now, salt has been regarded as a detrimental dietary factor," says first study author Jonathan Jantsch, a microbiologist at Universitätsklinikum Regensburg and Universität Regensburg. "Our current study challenges this one-sided view and suggests that increasing salt accumulation at the site of infections might be an ancient strategy to ward off infections, long before antibiotics were invented."
As to how science could have made such a mistake, Jantsch says it's puzzling that large amounts of sodium can be stored in the skin because they often lead to high blood pressure and increase risk for heart disease.
Why, then did that capacity evolve?
Jantsch and his team got their first clue as to why when they noticed that mice who had been bitten by cage mates carried an unusually high amount of sodium in their skin -- and found the same accumulation in infected skin areas of humans.
Intrigued, they conducted more experiments, which showed that a high-salt diet boosted the activity of macrophages, a type of immune cell capable of warding off a variety of pathogens.
Upcoming experiments include digging deeper into why salt accumulates in the skin of aging adults in the interest of designing drugs that could help localize the deposition.
"A further understanding of the regulatory cascades might not only help to design drugs that specifically enhance local salt deposition and help to combat infectious diseases, but also may lead to novel strategies to mobilize sodium stores in the aging population and prevent cardiovascular disease," says Jantsch.
The study, published in the journal Cell Press, could lead to salt-based wound dressings and antimicrobial therapies.
The researchers urge you to hold off from dietary changes until more research is completed.
"Due to the overwhelming clinical studies demonstrating that high dietary salt is detrimental to hypertension and cardiovascular diseases, we feel that at present our data does not justify recommendations on high dietary salt in the general population," says Jantsch.