Wednesday, December 18, 2013

Mercury Exposures and Autoimmune Diseases

As early as 1986 there were reports of a connection between multiple sclerosis and chronic exposure to mercury (Hg) from dental amalgam fillings.[1] Multiple sclerosis (MS) is a kind of autoimmune diseases (AD) —immune cells attack your body's own tissues when they should only attack outside invaders.

In this article, we will examine more scientific links between Hg and AD.

Autoimmune Diseases (AD)


Some autoimmune conditions are systematic, meaning that the attack spreads throughout the body to all tissues, as in lupus. Others are organ specific, for example, the affected area can be in:
There are more than one hundred different autoimmune conditions. They are all serious chronic diseases with an underlying problem in the immune system (i.e., failure to recognize self) and similar characteristics—inflammation. They also have strong sex bias in disease incidence and severity (see diagram).

Recently, environmental factors such as toxic metals have been suggested to play a significant role in AD pathogenesis. The cumulative effect of all these toxins can create a big toxic load on your body without your knowing it. Among all toxic metals, mercury is assumed to be one of the most toxic within nonradioactive elements.

Why Mercury Causes Autoimmune Diseases?


In [2], Dr. Blum surmised that mercury may induce autoimmune diseases by:
  • Altering or damaging the cells in your tissues
    • Making them look foreign to your immune system, which then attacks the cell.
  • Stimulating lymphocytes
    • Lymphocytes grow abnormally, losing their tolerance and ability to tell the difference between self and not self. Then they either directly attack or make antibodies to attack your own tissue.
However, this is a simplified view of a complex subject.  To read more on AD pathogenesis, read [3].

Some Scientific Evidences


Mercury (Hg) has long been recognized as a neurotoxicant; however, recent work in animal models has also implicated Hg as an immunotoxicant. In particular, Hg has been shown to induce autoimmune disease in susceptible animals with effects including overproduction of specific autoantibodies and pathophysiologic signs of lupus-like disease. 

While there is presently no evidence to suggest that Hg induces frank autoimmune disease in humans.  But the scientific evidence is mounting that Hg can at least make AD worse.  Also, some studies have demonstrated a link between occupational Hg exposure and AD.[7,11]

But the evidence is strongest for the association between mercury and autoimmune thyroid disease, which will be discussed in the next section).[2] Here are some studies that linked Hg exposure to AD:
  • A study out of the University of Milan reported the case of a patient with MS who had high levels of mercury, aluminum, and lead, and after he went through chelation, his MS symptoms improved.[4]
  • In many studies in rats, it have shown that mercury exposure can cause autoimmune diseases (i.e., MS and lupus) in rats.[5,6]
  • A study from the National Institute of Environmental Health Sciences in North Carolina found a strong link between lupus and self-reported mercury exposure and working in a dental office.[7]
  • A research has found a connection between higher levels of mercury with a positive ANA, which is the first sign of an autoimmune process that can lead to lupus.[8]
  • A research has found scleroderma patients had a higher concentration of mercury in their urine compared to patients without scleroderma antibodies.[9]

Autoimmune Thyroid Diseases


Because thyroid gland's location, it is especially susceptible to toxins coming from the mouth.  There are studies showing an association between dental amalgam (sliver) fillings (especially for those people who have a mercury allergy, meaning they make antibodies to the mercury), mercury exposure, and autoimmune thyroid disease.[2]
  • Researchers in the Department of Preventive Medicine at Stony Brook University looked at blood levels of Hg and anti-thyroid antibodies in women over the age of twenty who were not using birth control pills, not pregnant, and not lactating and found that those with the higher mercury levels had a much greater risk for having higher thyroglobulin antibodies.[12]
    • You can have these antibodies for two to seven years before your thyroid becomes damaged enough to show signs of thyroid hormone imbalances.
    • Elevated thyroglobulin antibody levels are very common in patients with rheumatoid arthritis, lupus, pernicious anemia, fibromyalgia,[13]chronic hives, and type 1 diabetes and suggests that these diseases are associated with mercury as well.  Therefore, the association found between mercury and these antibodies could indicate a broader relationship between mercury and other immune-related disorders.
Specifically, there are two types of autoimmune thyroid diseases:
  • Graves' disease
    • In which antibodies are stimulating the thyroid gland to be overactive
    • You can experience heart palpitations, weight loss and insomnia
    • Your eyes can begin to look like they are popping out, a condition called exophthalmos.
  • Hashimoto's thyroiditis
    • There are anti-thyroid antibodies blocking the thyroid gland's ability to make hormones, making it underactive.
    • You can experience
      • Extremely tired
      • Gaining weight
      • Losing hair
      • Having no sex drive
      • Having constipation
      • Feeling cold all the time

Diagram Credit

  • Johns Hopkins School of Public Health[3]

References

  1. Ahmad Movahedian Attar et al. Serum mercury level and multiple sclerosis. Trace Elem Res 2012; 146-150-153.
  2. The Immune System Recovery Plan by Susan Blum, M.D., M.P.H.
  3. Mercury Exposures and Autoimmune Disease (Johns Hopkins School of Public Health)
  4. A. Fulgenzi et al. A case of multiple sclerosis improvement following removal of heavy metal intoxication: lessons learnt from Matteo's case.  Biometals 2012 Jun; 25(3):569-576.
  5. Gilbert J. Fournie et al.  Induction of autoimmunity through bystander effects: lessons from immunological disorders induced by heavy metals.  J. Autoimm 2001:16:319-326.
  6. Benjamin Rowley and Marc Monestier.  Review: mechanisms of heavy metal-induced autoimmunity.  Mol Immunol 2005;42:833-838.
  7. Glinda S. Cooper Et al. Occupational risk factors for the development of systemic lupus erythematosus. J Rheumatol 2004;31:1928-1933.
  8. J.F. Nyland et al.  Biomarkers of methylmercury exposure immunotoxicity among fish consumers in Amazonian Brazil. Environ Health Perspect 2011 Dec; 119(12):1733-1738.
  9. F.C. Arnett et al. Urinary mercury levels in patients with autoantibodies to U3-RNP (fibrillin). J Rheumatol 2000 Feb;27(2):405-410.
  10. Caroly M. Gallagher and Jaymie R. Meliker.  mercury and thyroid autoantibodies in U.S. women, NHANES 2007-2008.  Environ Int 2013; 40:39-43.
  11. Mercury and autoimmunity: implications for occupational and environmental health.
  12. Caroly M. Gallagher and Jaymie R. Meliker.  mercury and thyroid autoantibodies in U.S. women, NHANES 2007-2008.  Environ Int 2013; 40:39-43.
  13. Fibromyalgia: Understand the diagnosis process
    • Your doctor can't detect it in your blood or see it on an X-ray. Instead, fibromyalgia appears to be linked to changes in how the brain and spinal cord process pain signals.
    • Possible fibromyalgia triggers
      • traumatic event, such as a car wreck
      • genetic factor
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