It is clear from the health effects of toxic metals that there is significant overlap with symptoms associated with environmental illnesses. Toxic metals are neurotoxic, causing cognitive dysfunction and interfere with energy metabolism resulting in fatigue and weakness, all hallmarks of environmental illnesses. Toxic metals trigger the production of free radicals, leading to oxidative stress and depletion of glutathione (the body's master antioxidant)1 as well as influencing the metabolism of metallothioneins (small metal binding proteins high in sulphur).2 Toxic metals are also known to stimulate the production of inflammatory messengers known as cytokines in the immune system.3 These effects and more are known to be important in environmental illnesses.
Chronic Fatigue Syndrome & Fibromyalgia
The symptoms of chronic fatigue syndrome (ME/CFS) and fibromyalgia alone are suggestive of metal toxicity being a contributing factor in at least some patients. Symptoms such as fatigue, poor memory and concentration, and "brain fog", could all be caused or exacerbated by toxic metals.
Research has suggested that allergic hypersensitivity to mercury and nickel from amalgam fillings causes inflammation which may affect the hypothalamic-pituitary-adrenal (HPA) axis and trigger multi-symptom conditions such as ME/CFS, fibromyalgia, and other environmental illnesses.4 An increased susceptibility to allergies and HPA-axis dysfunction have long been thought to be central to ME/CFS and fibromyalgia.
The immune and nervous systems are closely linked and it has been suggested that exposure to environmental stressors such as toxic metals could upset the delicate balance between them and lead to diseases such as ME/CFS where neuroimmune dysfunction is present.5
Through increasing oxidative stress toxic metals can damage mitochondrial DNA and cause mitochondrial dysfunction which inevitably leads to fatigue and other symptoms associated with ME/CFS and fibromyalgia.6 Toxic metals not only increase oxidative stress but also deplete glutathione, and the amino acid cysteine vital for its production, thus lowering the body's defences against free radicals. Increased oxidative stress and and depleted glutathione stores have been noted in several studies in ME/CFS patients7 and nutritional treatment of ME/CFS often includes efforts to restore glutathione concentrations to normal.
The role that mercury may or may not play in autism has been a subject of much debate. The mercury-containing vaccine preservative thimerosal has been blamed for the rapid increase in the numbers of children with autism and this has led to thimerosal being removed from most childhood vaccines. An important study published in 2007 found that the form of mercury in thimerosal (ethylmercury) does not accumulate in the brain and is quickly excreted from the body - the same study finding no link between thimerosal-containing vaccinations in infancy and neuropsychological functioning or the immune system's production of antibodies at ages 7 and 10 (news article).8 A later analysis of much of the same data from the Center for Disease Control and Prevention's Vaccine Safety Datalink (VSD) found that children with the highest mercury exposure from vaccines were 2 to 4 times more likely to develop a neurodevelopmental disorders than children with the lowest exposure (news article).9
Regardless of whether thimerosal in vaccines is to blame for autism, this does not settle the debate on whether mercury as a whole plays a role. The National Research Council's 2000 report on the toxicological effects of methylmercury concluded that the population at highest risk of mercury toxicity are children of women who consume large amounts of fish and seafood and that more than 60,000 children born each year in the US are at risk for adverse neurodevelopmental effects due to exposure to methylmercury in the womb.10 In 2008 a review of the existing scientific literature on epidemiological studies published in The International Journal of Risk and Safety in Medicine found that the evidence for a causal relationship between mercury exposure and autism is compelling. The author states that "Exposure to mercury (via vaccines and maternal dental amalgam) in utero and during infant years is confirmed; mercury poisoning is known to cause symptoms consistent with autism; animal modeling supports the link and, critically, mercury levels are higher in both the urine and blood of autistic children than in non-autistic peers." 11
Finally, substantial evidence now exists that oxidative stress, glutathione deficiency, and resulting injury to the brain may be the result of exposure to toxic metals including mercury, lead, and cadmium.12
Gulf War Syndrome
Studies have mainly focused on a possible link between depleted uranium (DU), a radioactive heavy metal, and Gulf War syndrome (see our Gulf War Syndrome page). However, troops were also exposed to various other toxic metals such as lead since military specification paints used on vehicles and bunkers, for example, often contain this toxic metal. Other sources of toxic metal exposure sustained by troops include vaccinations (mercury) and medications.
Of interest to individuals suffering from any environmental illness is research demonstrating that Candida albicans is highly efficient at converting the less toxic elemental mercury found in dental amalgam fillings for example, to the highly potent toxin methylmercury.13 Intestinal overgrowth of Candida has been implicated in most environmental illnesses including ME/CFS14, autism15, and irritable bowel syndrome16 and could therefore amplify the toxicity of any mercury taken into the body in these people.
Useful Books - In association with Amazon