Why a new study will make you think twice before reaching for the saltshaker
How Autoimmune Diseases Start
Autoimmune diseases are disorders that result from the body initiating an inappropriate immune response either to its own proteins, or to substances that are normally found within the body. Common autoimmune diseases include celiac disease, Crohn’s disease, psoriasis, rheumatoid arthritis, and multiple sclerosis, but that is just the tip of the iceberg as there are currently as many as 80-100 disorders that are linked to autoimmunity.
How to treat Autoimmune Diseases?
The common feature of all these diseases is that they are chronic, debilitating, and life threatening. Currently, immunosuppressants are the only effective treatment for autoimmune diseases but they are associated with serious side effects. This arises from the fact that most of them are non-selective, causing immunodeficiency that can increase susceptibility to infections and cancer. The NIH estimates that 23.5 million Americans suffer from autoimmune diseases and that this number is on the rise. The NIH also estimates that the annual direct healthcare cost for autoimmune diseases is a whopping $100 billion. These diseases are becoming an epidemic, particularly in industrial countries, and researchers still aren’t sure as to whether this is due to lifestyle choices or chemicals in the environment. However, two concurrent studies just recently published point to salt in the diet as a major culprit that may trigger the development of autoimmune diseases[3-4].
What is causing Autoimmune Disease?
It seems that salt exerts its affects by impacting cells of the immune system called T-lymphocytes. T-lymphocytes in turn produce substances called cytokines that are crucial for initiating an immune response. The studies showed that salt specifically acts on one type of T-lymphocyte called the Type-17 helper (Th17). Th17 lymphocytes are required to produce various cytokines including interleukin-17 (IL-17) that defends the body against bacterial and fungal infections by inducing an inflammatory response. While inflammation is a normal reaction to infection, it is characterized by pain, heat, redness, and swelling. With autoimmune diseases, the inflammation process is on-going which can be severely damaging and painful. Due to their ability to induce inflammation, Th17 lymphocytes have previously been linked to autoimmune diseases. Interestingly, recent studies showed that modest increases of salt in the diet increased the Th17 inflammatory response, and mice fed an increased salt diet were shown to develop encephalomyelitis, the mouse equivalent of multiple sclerosis[3-4].
What you can do to reduce your risk of developing autoimmune diseases
While these results are very compelling, researchers warned that they are still unclear of the medical implications of their findings. The risk of developing autoimmune diseases is linked to specific genetic variations in genes of the immune system. Therefore, those with a family history of autoimmune diseases may opt for a genetic test to determine if they too are at risk for developing these diseases, and can alter the sodium content in their diets accordingly. Figure from International Genetics of Ankylosing Spondylitis Consortium (IGAS) showing that variants in genes associated with the autoimmune disease ankylosing spondylitis also overlap with those of other autoimmune diseases.
If you would like to learn more about healthy living, continue reading this related blog post: “Is Bacteria The Reason For Obesity?”. If you enjoyed this post and want to read more, please follow us on Twitter or become a fan on Facebook. Author: Antonia Borovina
- J. Ermann and C.G. Garrison, Autoimmune diseases: genes, bugs and failed regulation, Nature immunology, 2 (2001), 759-761
- The American Autoimmune Related Diseases Association
- C. Wu et al. Nature Advanced Online Publication http://dx.doi.org/10.1038/nature11984(2013).
- M. Kleinewietfeld et al., Nature Advance Online Publication http://dx.doi.org/10.1038/nature11868 (2013).
- International Genetics of Ankylosing Spondylitis Consortium, Identification of multiple risk variants for ankylosing spondylitis through high-density genotyping of immune-related loci, Nature Genetics, 45 (2013), 730-738