The Link Between Rheumatoid Arthritis and Heavy Metal Toxicity
written by: Dawn Salamon
• edited by: lrohner
• updated: 5/15/2011
The exact cause of rheumatoid arthritis is unknown but could exposure to heavy metals such as lead, mercury and iron be partly to blame? Learn more about the link between heavy metal toxicity and rheumatoid arthritis.
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Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic symmetrical inflammation of the joints and the surrounding tissues. The disease affects approximately 1.3 million people in the United States, and is more common in women than men (70 percent of patients with RA are women). Generally, rheumatoid arthritis occurs between the ages of 40 and 60, but women can show signs as early as age 30. Interestingly, RA affects all races equally, unlike some autoimmune diseases which tend to affect minority populations more frequently.
Although the exact cause has not yet been determined, researchers believe that some combination of genetics, environmental factors and infections are to blame. What researchers are also finding is that there may be a link between heavy metal toxicity and rheumatoid arthritis. Studies show that prolonged exposure to certain heavy metals, such as cadmium, copper, iron, lead and mercury - all found in products used on a daily basis - can cause rheumatoid arthritis-like symptoms.
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Rheumatoid Arthritis and Autoimmune Disease
The most common symptoms of rheumatoid arthritis are pain, redness, stiffness and swelling at the joints. Over time, this inflammation can lead to deformity of the joints due to cartilage, bone and ligament damage, as well as the development of rheumatoid nodules or lumps of tissue under the skin in bony areas. Other symptoms include fatigue, loss of energy, low-grade fever and loss of appetite.
Rheumatoid arthritis causes the immune system to attack the body’s own tissue instead of focusing on foreign bodies such as bacteria and viruses. In the case of rheumatoid arthritis, the immune system specifically targets the synovium (the thin membrane that lines the joints). Once the synovium has been attacked, there is a build-up of fluid in the joints, resulting in inflammation, which can then spread to other tissues in the body.
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The Effect of Heavy Metal Exposure on the Immune System
In a healthy person, the lymphatic system releases white blood cells in the form of lymphocytes in response to any bacteria or virus that invades the body. These lymphocytes are divided into B cells and T cells. B cells are responsible for producing antibodies to fight bacteria and other foreign bodies, while T cells attack the body's own cells that have been affected by viruses, bacteria or cancer. Also, cytokines, which are proteins released by cells of the immune system to act as "mediators" between other cells, are discharged to help provide protection through inflammation to the injured area. In a patient with rheumatoid arthritis, the relationship between B cells and T cells behaves abnormally, resulting in the B and T cells attacking healthy tissue and an over-release of cytokines, causing inflammation.
Evidence from studies conducted on both human and animal populations show that chronic exposure to heavy metals, especially lead, cadmium and mercury, have a similar effect on the immune system. A study conducted in Poland showed that prolonged exposure to lead and cadmium caused an increase in cytokine production as well as a decreased number of existing B and T cells. Another study conducted in the United States on dental amalgams containing mercury produced similar results. This disruption in the normal functions of the B cells, T cells and cytokines results in the immune system attacking its own cells, which can lead to rheumatoid arthritis and other joint diseases.
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Cause or Contributing Factor?
Research shows that genetics appear to play a large role in who is affected with this disease. According to the Arthritis Foundation, people with the genetic markers for rheumatoid arthritis are 10 times more likely to develop the RA. Having the genetic marker does not guarantee the onset of the disease, nor do all people with RA have the genetic markers associated with it. Bacterial or viral infections, stress, smoking, and heavy metal exposure are all considered contributing factors in developing rheumatoid arthritis.
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Arthritis Foundation website, http://www.arthritis.org/rheumatoid-arthritis.php