Source Newsroom: American Autoimmune Related Diseases Association (AARDA)
Newswise — DETROIT, March 8, 2013 – In the newest issue of Nature, three new studies describe a link between the increase in incidence of autoimmune diseases, such as multiple sclerosis and type-1 diabetes, in recent decades with the use of salt.
Dr. Noel R. Rose, American Autoimmune Related Diseases Association’s (AARDA) Scientific Advisory Board Chairman Emeritus and Johns Hopkins Center for Autoimmune Research Director, issued the following statement on the new studies:
Since autoimmune diseases are increasing in the United States and most other industrialized countries, great interest has been devoted to agents that may be associated with societal exposures.
One group of investigators at Yale University decided that the increasing use of salt in the typical Western fast food diet may be a likely candidate to be an environmental trigger. Another investigative team at Harvard and MIT took a different approach.
They started with a large family of inflammatory mediators that have been implicated in a number of experimentally-induced autoimmune diseases termed Th17. Surprisingly, the most prominent regulator of Th17 turned out to be an enzyme responsible for the absorption of salt. Both groups, therefore, went on to test the effect of salt on Th17 production in the test tube and in experimental animals.
There is as yet no firm evidence that the Th17 family plays the same role in autoimmune disease in humans and clinical trials are underway.
However, there is one example where salt has a role in contributing to susceptibility to autoimmune disease. The thyroid gland depends upon dietary iodine to produce its functional thyroid hormone. Patients with insufficient salt may become hypothyroid and so salt in the United States usually contains added iodine.
However, excessive amounts of iodine have been shown in careful epidemiological studies to be associated with a greater risk of autoimmune thyroid disease. These studies have been reinforced with detailed investigations using experimental animals. Adding iodine to their diet increases greatly the occurrence and severity of thyroiditis in genetically highly susceptible mice or rats.
The bottom line is that it may well be that the lessons learned from prior studies of autoimmune thyroid disease will be applicable to the study of salt and other autoimmune diseases now and in the future.
American Autoimmune Related Diseases Association (AARDA) is the nation's only non-profit organization dedicated to bringing a national focus to autoimmunity as a category of disease and a major women's health issue, and promoting a collaborative research effort in order to find better treatments and a cure for all autoimmune diseases. For more information, please visit www.aarda.org.