A high-salt diet increases the risk of heart disease and stroke, which are the two leading causes of death worldwide, but it could also have an advantage. According to a new study, dietary salt defends the body against invading microbes because sodium accumulation in the skin can boost the immune response to a skin-infecting parasite.
The findings suggest that dietary salt could have therapeutic potential to promote host defense against microbial infections, Science Daily reports.
“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 first study author Jonathan Jantsch, a microbiologist at the University of Regensburg, in Germany.
“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.”
The overwhelming evidence linking dietary salt to disease show that sodium stored in the skin, especially in older individuals, can lead to high blood pressure and increase the risk for heart disease and stroke, it can worsen autoimmune disease and even increase the risk of stomach cancer. But for the first time, researchers observed some benefits after they noticed an unusually high amount of sodium in the infected skin of mice that had been bitten by cage mates. Further examinations showed that a high-salt diet in mice boosted the activity of immune cells called macrophages, thereby promoting the healing of feet that were infected with a protozoan parasite called Leishmania major.
“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,” Jantsch explained.
“We also think that local application of high-salt-containing wound dressings and the development of other salt-boosting antimicrobial therapies might bear therapeutic potential.”
Scientists mentioned that they don’t recommend high dietary salt in the general population, but supplementation of salt might be a therapeutic option in situations where endogenous accumulation of salt to sites of infection is insufficient.