The dietary tides are once again turning for salt.
You may remember a landmark JAMA study in 2011 that showed that contrary to what the medical community espoused for years – salt actually lengthens your life; it doesn't cut your life or raise the risk of hypertension. That study found that people actually lived longer if they consumed salt. Notably, they were not studying pink Himalayan salt, but regular old, processed table salt.
Additionally, a Cochrane study confirmed that salt did not cause heart or blood pressure problems and that reducing the substance offered no reduction of heart risks.
Now researchers, in a study published by Cell Press March 3rd in Cell Metabolism reveals that dietary salt could have a biological advantage: defending the body against invading microbes.Study author Jonathan Jantsch, a microbiologist at Universitätsklinikum Regensburg and Universität Regensburg said:
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.
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.
A press release goes on to say:
A high-salt diet increased sodium accumulation in the skin of mice, thereby boosting their immune response to a skin-infecting parasite. The findings suggest that dietary salt could have therapeutic potential to promote host defense against microbial infections.
Senior study author Jens Titze adds:
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.
They first curiously teamed up to study this idea when they noticed that some wounded cage mice had unusually high amounts of salt accumulated at the infected wound sites.
They found that infected areas in patients with bacterial skin infections also showed remarkably high salt accumulation. Moreover, experiments in mice showed that a high-salt diet boosted the activity of immune cells called macrophages, thereby promoting the healing of feet that were infected with a protozoan parasite called Leishmania major.
As always, they must offer a caveat, as one does not flippantly violate one of the biggest medically dogmatic tenants of the last century.
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.
Nevertheless, in situations where endogenous accumulation of salt to sites of infection is insufficient, supplementation of salt might be a therapeutic option. But this needs to be addressed in further studies.
Could these findings mean that various kinds of salt baths could offer protection too? Jantsch says, “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.” The benefits of the Dead Sea rings a bell.