Scientists at Vanderbilt University in Germany conducted a study whose results go against traditional recommendations to avoid high-salt diet. In their study, researchers claim high-salt diet acts as a defender against microbes by using the sodium accumulation in skin to boost the immune system response against skin-infecting parasites.
The study was published in the Cell Press journal Cell Metabolism.
Jonathan Jantsch is a microbiologist at microbiologist at Erlangen and Regensburg Universities in Germany.
“Up to now, salt has been regarded as a detrimental dietary factor; it is clearly known to be detrimental for cardiovascular diseases, and recent studies have implicated a role in worsening autoimmune diseases,” said Jantsch, first study author. “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,” Jantsch said.
Common recommendations state that large amounts of sodium stored in the skin, especially in older individuals, lead to high blood pressure and increase the risk for heart disease and stroke.
“Despite the overwhelming evidence linking dietary salt to disease in humans, the potential evolutionary advantage of storing so much salt in the body has not been clear,” said senior study author Jens Titze, who studies the link between sodium metabolism and disease at Vanderbilt University School of Medicine in the US.
Titze and his team had an idea about the role of high concentrations of salt after noticing the unexpectedly high amount of sodium in the skin infected of mice bitten by other mice in the cage.
After Titze teamed up with Jantsch to examine the link between infection and salt concentrations in the skin, they found that infected area in patients with bacterial skin infections also present an elevated level of salt.
Additionally, experiments with mice demonstrated that a diet rich in salt increased the activity of immune cells called macrophages, causing faster heading of feet infected with parasites.
“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 ageing population and prevent cardiovascular disease,” Jantsch said.