Consuming too much salt is not only bad for blood pressure and the cardiovascular system, but can also have a negative impact on the immune system.
Excess salt lowers energy production in cells that regulate immune system responses to prevent them from becoming excessive, according to a study published in February 2023 in the journal Cell Metabolism.
Salt affects the innate immune system
Previous studies by the same research team have shown that excess salt in the diet can have negative effects on the metabolism and energy balance of certain types of innate immune cells, monocytes and macrophages, and prevent them from working properly. They also showed that salt triggers malfunctions in mitochondria, the “powerhouses” of cells.
The impact of salt on the adaptive immune system
Inspired by these results, Dominik Müller and Markus Kleinewietfeld, respectively from Max Delbrueck Center (Germany) and the Hasselt University (Belgium), and their colleagues wondered if excessive salt intake could create a similar problem in adaptive immune cells like regulatory T cells (or regulatory T lymphocytes) (Tregs).
These cells are responsible for maintaining the balance between normal immune system function and excessive inflammation. Tregs are sometimes referred to as the “police of the immune system” because they ward off undesirables, such as self-reactive immune cells (which attack the body itself), and ensure that immune responses proceed from controlled manner without harming the body.
Scientists believe that the dysregulation of Tregs is linked to the development of autoimmune diseases such as multiple sclerosis. Recent research has identified problems in the mitochondrial function of Tregs from patients with autoimmunity, but contributing factors remain unknown.
Previous research has also shown that excess salt can impact the function of Tregs by inducing an autoimmune-like phenotype, that is, by inducing changes in these cells similar to those implicated in autoimmune diseases. However, the exact way sodium impairs Treg function had not yet been discovered.
Salt interferes with mitochondrial function of Tregs
The new study shows that sodium disrupts the function of Tregs by altering cellular metabolism through interference with mitochondrial energy production. This mitochondrial problem appears to be the initial step in how salt alters the function of Tregs, leading to changes in gene expression that bear similarities to those of dysfunctional Tregs in autoimmune diseases.
Even short-term disruption of mitochondrial function has lasting consequences on the immune regulatory capacity of Tregs in various experimental models.
« Since Tregs also play a role in diseases such as cancer or cardiovascular disease, further exploration of these sodium-triggered effects could offer new strategies to modify Treg function in different types of diseases.
». « But future studies are needed to understand the molecular mechanisms in more detail and to clarify their potential relationship to disease.
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For more information, see the links below.
(1) Beatriz F. Côrte-Real, Ibrahim Hamad, Rebeca Arroyo Hornero, Sabrina Geisberger, Joris Roels, Lauren Van Zeebroeck, Aleksandra Dyczko, Marike W. van Gisbergen, Henry Kurniawan, Allon Wagner, Nir Yosef, Susanne NY Weiss, Klaus G. Schmetterer, Agnes Schröder, Luka Krampert, Stefanie Haase, Hendrik Bartolomaeus, Niels Hellings, Yvan Saeys, Ludwig J. Dubois, Dirk Brenner, Stefan Kempa, David A. Hafler, Johannes Stegbauer, Ralf A. Linker, Jonathan Jantsch, Dominik N. Müller, Markus Kleinewietfeld.
Psychomedia with sources: Cell Metabolism, Max Delbrueck Center.
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