Heavy Metal Toxicity: An Overview

BY: DR. JULIE MILLER

Heavy metal toxicity refers to an excessive build-up of toxic metals in the body that can contribute to numerous chronic degenerative diseases, such as cardiovascular disease, Alzheimer’s disease, and multiple sclerosis. However, accumulation of toxic metals can also cause vague symptoms such as: chronic pain, chronic fatigue, brain fog, mood disturbance (mood swings, depression, and/or anxiety), headaches, dizziness, digestive disturbance, chronic infections, and neurological symptoms such as numbness, tingling, burning or paralysis. Such symptoms are often unexplained or misdiagnosed as other conditions.

The term “heavy metal” is used because the majority of these metals, such as lead, mercury, cadmium, and arsenic, are 5 times heavier than water. However there are other metals, such as aluminum, that are also toxic but aren’t classified as “heavy”.

In the modern world, our environment, food, and water regularly expose us to these toxic metals which, over time, accumulate in our bodies and negatively impact normal cellular function.  The disruptive effects of these metals are numerous including:

• Inflammation: toxic metals place tremendous stress on our anti-oxidant systems and contributes to the development of atherosclerosis and cardiovascular disease
• Nerve Damage: research out of the University of Calgary has shown a causative relationship between mercury exposure and nerve degeneration (for a video explanation please seehttp://www.iaomt.org/patients/video.asp?page=0&vid=1)
• Kidney Damage: the kidneys help to detoxify heavy metals from our body and are particularly susceptible to toxic metal-induced damage
• Immune Dysfunction: not only do toxic metals reduce our body’s abilty to fight infections and destroy cancer cells, but they can also contribute to autoimmune processes by making self-proteins targets for the immune system
• Mineral Disruption: heavy metals can bind onto essential minerals and prevent their proper function in the body. For example, 95% of lead in the body is stored in the bone, which displaces calcium and other minerals and can contribute to the development of osteoporosis.
• Endocrine Disruption: including hormonal imbalance, infertility, and hypothyroidism

When numerous metals are present in the body they exhibit synergistic toxicity meaning that the combined toxicity is much greater than the effect of each metal on its own.  For example, a research article published in 1978 by Shubert, Riley, and Tyler in the Journal of Toxicology and Environmental Health demonstrated that a dose of mercury sufficient to kill 1% of tested rats, when combined with a dose of lead sufficient to kill less than 1% of the rats, resulted in killing 100% of the rats tested.

Although many of these metals are found in the air, water, and soil, either naturally or as a result of industrial contamination, there are also specific sources that contribute to the majority of human exposure.

1. Mercury

• Silver amalgam dental fillings are composed of 50% elemental mercury. Chewing stimulates the release of mercury vapour from the fillings that is 1000 times higher than the level that Environmental Protection Agency (EPA) will allow for the air we breath.
• Many vaccines contain thimersol, a mercury containing preservative.
• Dietary sources include: large fish such as tuna, swordfish, and shark (seehttp://www.nrdc.org/health/effects/mercury/walletcard.pdf for a pocket guide to mercury content in fish), shellfish, and high fructose corn syrup. Over 95% of the mercury in fish (methymercury) is absorbed into the body.
• Occupational exposure including dentistry and certain industrial/manufacturing processes.

2. Lead

• Prior to the 1970s, lead was found in house paint, gasoline, and in water pipes (as lead pipes or lead solder).
• Other sources include: candle wicks, cosmetics including lipstick, car batteries, ceramic glazes, fishing weights
• Occupational exposure including: welding, ammunition manufacture and disposal, machining, and renovations/remodelling

3. Arsenic

• By product of smelting, mining and coal burning
• Other sources include: insecticides, rodent poison, fungicides, drinking water, seafood, and  pressure treated wood

4. Cadmium

• Commonly found in industrial workplaces, especially where ore is processed or smelted
• Cigarette smoke
• Other sources include: artist and automotive paint pigments, batteries (nickel-cadmium), and seafood

5. Aluminum

• Sources include: antacids, anti-perspirants, vaccines, baking powder, aluminum cookware and cans, cosmetics, as well as many industrial/manufacturing uses