Too much salt damages our immune system
If you like to eat salty, it may harm your health. For a high intake of salt, according to a group of Berlin researchers, the body's defenses adversely affect and thereby lead to a slow wound healing. According to scientists in the Journal of Clinical Investigation (JCI), too much salt in the diet would weaken a specific group of immune system phagocytes..
Increased risk of cardiovascular disease
Salt is a vital mineral for the body. But those who take in too much risk damaging their health, such as Hypertension and cardiovascular diseases such as a heart attack or stroke.
But that's not all. As reported by the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), a team of Berlin scientists has now shown that too much salt also harms the immune system. According to this, Dr. Katrina Binger, Matthias Gebhardt and Prof. Dominik Müller from the Experimental Clinical Research Center (ECRC) have succeeded in proving that increased salt intake in rodents resulted in slower wound healing. The ECRC is a joint institution of MDC and the Charité-Universitätsmedizin Berlin.
Salt in large quantities damages certain form of phagocytes
As the MDC states, it has been known for a few years that too high a salt content in the diet can affect the immune system in different ways. However, the Berlin researchers have now demonstrated in their study, that this will weaken a certain group of so-called "macrophages". These belong to the immune system as large, mobile "phagocytes" and are responsible among other things for combating inflammation in the body. Specifically, the immune cells were Type 2 macrophages stimulated by the messengers of the immune system (IL-4 and IL-13), the report said. Therefore, the researchers suspect that the delayed wound healing in the rodents is also due to the salt-induced weakening of the special phagocytes.
Recently, a team of researchers led by Professor Jens Titze of Vanderbilt University in Nashville, Tennessee, together with the Berlin scientists, discovered a new salt reservoir in the body, the MDC continues. Accordingly, it has been shown that excess salt does not accumulate in the blood, but in the interstices of skin and muscle cells. Based on these findings, the three MDC scientists were finally able to clarify how it comes to the weakening of macrophage activity by saline.
As early as 2013, first insights into the relationship between salt and the immune system
In 2013, Prof. Dominik Müller of the ECRC and other scientists had already discovered another effect of salt on the immune system in the context of a study. As the MDC said, could be proven at that time that too much salt promotes the development of autoimmune diseases. Because of a high salt intake, the number of aggressive "Th17 helper cells" would increase massively, which are associated with the development of chronic inflammation and autoimmune diseases.
Further study brings seemingly contradictory results
However, according to the report together with Prof. Jens Titze and other colleagues, Berlin researchers Müller, Binger and other colleagues proved this spring that salt in larger quantities in rodents as well as in humans actually boosts the immune system and bacterial infections in the stomach could heal the skin quickly. Because the salt is deposited in the skin and lead in the case of a bacterial skin infection to an activation of macrophages of type 1 - and thus to an increased release of bactericidal substances, the researchers said at the time in the journal "Cell Metabolism".
Further studies could explain an increasing number of autoimmune diseases
Nevertheless, according to Prof. Müller, it should now not be started to increase the salt consumption, because "the risks outweigh the benefits," warns the expert. The apparently contradictory findings should therefore not be misinterpreted. Because "these supposedly contradictory findings suggest that the macrophages can adapt very differently to a milieu that changes due to an increased salt level in the body," Müller continues.
"Overall, we hypothesize that the entire balance between the effector and the regulatory arms of the immune system is disturbed by salt," the researchers write in the "Journal of Clinical Investigation." Therefore, further studies on this topic are essential "to understand the increased incidence of inflammatory and autoimmune diseases in Western societies," the researchers conclude. (No)