Q Feeling under the weather recently, I underwent a series of tests for evidence of toxins to explain my poor health and persistent lack of energy. The results from my urine tests revealed high levels of lead, mercury, aluminium and, in particular, cadmium, which was 20 times above the acceptable level.
Am I just an alarmist, or do most people, in this modern age, have similarly high levels of toxic materials in their systems? I have been a potter for 30 years and this could account for the high levels of some of these metals as they do occur in small amounts in glazes; we also do use some metal oxides.
The doctor made several suggestions for reducing the level of mercury in my body, including taking a course of DMSA, removing 15 amalgam fillings from my teeth and undergoing chelation therapy after each dental visit. Will this regime work, and what should I do to lower the levels of the other metals? - Duffy Bocking, County Down, Ireland
A You are not alone. Heavy-metal poisoning is an increasingly prevalent medical condition worldwide. In the US, it is estimated that one in four suffers from some degree of poisoning due to toxic metals (Krapp K, Longe JL, eds. Gale Encyclopedia of Alternative Medicine. Detroit, MI: Gale Group, 2001). People such as yourself, whose exposure to these metals is higher of necessity because of your occupation, are particularly susceptible to such poisoning. Physicians, cosmetic workers, printers, welders, hairdressers, photographers, visual artists, painters and, of course, potters are just a fraction of the professions that entail high exposure to mercury alone (J Orthomolec Med, 1987; 2: 15-21).
Heavy metals can enter the system via food, water, air or through the skin. In general, they home in on vital organs such as the gut, liver, kidneys and skin, and clog up detoxification pathways, eventually leading to illness. They also disrupt immune system function and deplete energy, hence, your chronic lack of energy. The reproductive and hormonal systems are also known to fall victim to high-level exposure to toxic metals.
The nervous system is particularly vulnerable to lead and mercury poisoning. Long-term lead exposure can result in abnormal physical movement (Scand J Work Environ Health, 1985; 11 [Suppl 4]: 20-5), high blood pressure, anaemia (Nutrition, 2003; 19: 571-6) and brain damage, at least in rats (Hum Exp Toxicol, 2003; 22: 417-23).
Mercury in its organic form (such as the mercury vapours released from dental amalgam fillings may be particularly damaging to the nervous system. It is capable of crossing the blood-brain barrier and, thus, can affect parts of the brain and their associated functions. Symptoms of mercury-related brain damage include personality changes (mood swings, irritability, shyness, nervousness), tremors, changes in eyesight, deafness, lack of muscle coordination, and sensory and memory loss. In its inorganic form, mercury can cause damage to the kidneys, stomach and intestines.
Considering your very high levels of cadmium, your greatest concern is probably cadmium poisoning. In general, cadmium emission levels in the environment have soared in the last century (Br Med Bull, 2003; 68: 167-82). This is because products containing cadmium are rarely recycled, but often disposed of together with household waste. In your case, as you've already pointed out, the cadmium in your system is most likely due to having to work with cadmium-containing glazes.
Cadmium accumulates mostly in the liver and kidneys, and there's a substantial body of evidence showing that long-term cadmium exposure can cause kidney disease and bone loss (Scand J Work Environ Health, 1998; 24 [suppl 1]: 1-51). Breathing in high levels of cadmium severely damages the lungs, and animals given cadmium-laced food or water have developed high blood pressure, iron deficiency, liver disease and nerve or brain damage, according to the US Agency for Toxic Substances and Disease Registry report Toxicological Profile for Cadmium (Atlanta, GA: US Department of Health and Human Services, 1992). A recent study in rats found that cadmium's oestrogen-mimicking effects resulted in changes to the animals' reproductive system (Nat Med, 2003; 9: 1081-4).
Chelation therapy is now the main port of call for heavy-metal detox. Since being first developed to treat accidental toxic metal poisoning 50 years ago, chelation has proved to be an efficient way to remove toxic substances from the body (J Adv Med, 1993; 6: 139-60). The process involves the use of a chelating amino acid that binds to metal ions in the blood and tissues - thus changing their chemical composition and limiting their toxicity - and removing them from the body.
In the early days, a major hitch with the chelating chemical ethylenediaminetetraacetic acid (EDTA) was that it removed not only toxic metals, but also essential ones like zinc, calcium and iron. It has since been succeeded by DMSA (dimercaptosuccinic acid), which is lead- and mercury-specific.
DMPS (dimercapto-1-propanesulphonate) is another new-generation chelating agent, but studies suggest that it may not be as good as DMSA in removing lead (Chem Res Toxicol, 1994; 7: 585-9) or cadmium (J Toxicol Environ Health, 1996; 47: 173-82).
However, despite the advantages, chelation is a costly treatment of limited availability. Nevertheless, there are more natural courses of action for detoxification of heavy metals, which can be broadly classed under avoidance and nutrition:
* Avoid or limit environmental exposure to these toxins. To speed up your body's repair, it is essential to remove and minimise contact with the source of these noxious agents.
* Remove any dental amalgam fillings, as already suggested by your doctor.
* Keep your workplace well ventilated. A study looking at ceramists working with cadmium- and lead-containing glazes showed that those whose studios were keep well-aired had significantly lower levels of these toxic metals in their hair (J Toxicol Environ Health, 1991; 34: 423-31).
* If you're a smoker, quit. Cigarette-smoking is a major source of cadmium exposure (Br Med Bull, 2003; 68: 167-82).
* Avoid or limit certain high-risk foods that are a potential sources of lead, mercury and cadmium: shellfish, coastal and inland freshwater fish, and deepsea fish such as tuna, swordfish and shark; intensively farmed meat and offal, especially liver and kidneys; vegetables and fruit sprayed with pesticides; processed foods, alcohol and caffeine.
* Eat a well-balanced diet. There's a raft of evidence underscoring a connection between a poor diet and an increased uptake of toxic metals. Cadmium, for example, is absorbed more readily in the digestive tract when there is a low dietary intake of calcium, amino acids, zinc, iron and copper (J Environ Qual, 1988; 17: 175-80).
* Stick to a low-fat, high-fibre diet containing plenty of free-radical-busting phytochemicals such as glucosinolate-rich vegetables (such as onions, garlic, broccoli, brussels sprouts, cabbage, cauliflower and kale).
* Drink plenty of mineral water every day to help flush out toxins.
* Help support your liver with nutritional supplements that aid detoxification:
vitamins A, B-complex and C, selenium, magnesium and zinc make a good detox foundation
extracts of grapeseed, milk thistle, turmeric root and/or globe artichoke leaves can all increase the production of glutathione transferase, an amino acid that chelates toxic compounds and flushes them out of the body
NAC (N-acetylcysteine), a form of the essential amino-acid L-cysteine, is converted into metabolites that also stimulate glutathione synthesis. NAC is also liver- and kidney-protective while enhancing heavy-metal elimination (Alt Med Rev, 1998; 3: 114-27)
MSM (methylsulphonylmethane), a naturally occurring sulphur compound, is used as the sulphur component required for chelation. An animal study found that cadmium was removed from the bloodstream of rats given two sulphur-containing amino acids, methionine and cysteine (Biol Trace Elem Res, 2000; 76: 19-30).
spirulina, a blue-green, freshwater algae, is frequently used to aid the elimination of heavy metals from the body.