Exposure to heavy metals has been linked to many chronic health conditions including autoimmunity, ME, cancer, neurological diseases and developmental problems in children.
What are heavy metals?
Heavy metals are, by definition, metals of high relative density or atomic weight. Some heavy metals are seen to be beneficial or harmless in appropriate doses, such as zinc, cobalt and iron, whereas others are highly toxic. These include mercury, lead, chromium (in its hexavalent form), cadmium and arsenic. Aluminium is often grouped into this category, where as it is in fact a light metal, although still toxic and capable of causing harm to health.
All of these heavy metals appear to have a strong affinity for sulphur and bind, via thiol groups, to create sulphur-metal bonds. These bonds can then inhibit the enzymes that control metabolic reactions, causing DNA damage and deterioration in human health with wide ranging symptoms and consequences throughout the body including the respiratory, digestion, immune and central nervous systems. Heavy metals are also found in the placenta during pregnancy, and in the mother’s breast milk, impacting the health of the baby during pregnancy and beyond.
How are we exposed to heavy metals?
• Lead – found in many places including exhaust fumes and paints (thankfully now banned), industrial waste, batteries and water supply from lead pipes. Exposure mainly occurs through inhalation of lead-contaminated dust particles, in crystal and ceramic containers, cosmetics – namely lipsticks, and ingesting lead-contaminated food and water.
• Mercury – mercury that has been released into the air from factories, as well from pesticides, has permeated our soils and waterways. Many fish are contaminated with mercury, with larger fish further up the food chain, such as tuna and swordfish, more saturated than smaller fish, such as sardines and anchovies. Many of us are also exposed to elemental mercury from amalgam fillings in our teeth. The vapour given off by the elemental mercury is highly lipophilic and absorbed through the lungs as well as tissues lining the mouth. Other sources include cosmetics and vaccines. It is essential that all people with amalgam filling have these out at some point soon in their life as Mercury is considered either the first or second most toxic element in existence and finds its way into the tissues.
• Cadmium – used in alloys, pigments and batteries, plus it has been found in toy jewellery. Exposure tends to come predominantly from cigarette smoke and through food such as vegetables, organ meats and shellfish, plus through emissions from contaminated industries such as mining and smelting. It is very difficult to remove from the body because it has a long half-life of 10-20 years.
• Arsenic – several arsenic-containing compounds have been used to manufacture pesticides and wood preservatives. Arsenic-based drugs are used to treat certain tropical diseases and in veterinary medicine to treat parasites. Recently, arsenic trioxide has been approved for use in the treatment of leukemia. Several million people are chronically exposed to arsenic in countries like Bangladesh, India, China, Mexico, and Taiwan, where the ground water is highly contaminated. Arsenic also finds its way into our diets through the intake of rice, and children under five are not recommended to consume rice milk for this reason.
• Chromium – hexavalent chromium is a toxic industrial pollutant that enters the air, water and soil from industries such as metal processing, chromate production and stainless steel welding.
Symptoms of heavy metal toxicity
Symptoms are varied and dependent on the level and duration of exposure, including…
Poor attention span
Numbness and tingling
Loss of peripheral vision
Skin rashes and dermatitis
Nausea, vomiting and diarrhoea
Gum and mouth inflammation
Testing for heavy metals
There are various ways of testing for heavy metals and we detail those below:
1. Provoked urine toxic metals test.
2. Melisa test for metal sensitivity which shows loss of immune tolerance and is useful for assessing compatible dental materials.
3. Toxicity Testing and Cyrex array 11 which tests for chemical immune reactivity.
4. Mercury Tri Test – this test uniquely measures body burden of mercury both organic and inorganic. It also measures the excretion/detox ability.
Detoxification of heavy metals from the body
When considering heavy metal detoxification, it is first important to mention glutathione, because it plays a crucial part in the body’s ability to detoxify harmful substances. Glutathione is an intra-mitochondrial antioxidant found inside every cell and in highest concentrations in the liver. Glutathione is used extensively in the body, mopping up free radicals and binding with toxins, such as heavy metals, for excretion via the liver and in urine. It can easily become depleted if demand exceeds supply, and if there is insufficient glutathione then the body will be less able to deal with heavy metal exposure, and harmful levels will accumulate. Depletion of glutathione is linked to neurodegenerative, immune, cardiovascular and liver disease, plus cystic fibrosis and accelerated ageing – all are indicative of glutathione depletion and suggest the need to increase levels.
So how do we get more glutathione? Or more importantly, how do we get more reduced glutathione, which is the form we need for cell protection? Reduced glutathione is made available to the body in 3 ways…
1. De novo glutathione synthesis – a process that converts the amino acid cysteine into glutathione. Availability of cysteine is therefore crucial.
2. Regeneration of oxidised (damaged) to reduced glutathione – oxidised glutathione naturally pairs with available glutathione in the cell, returning the oxidised glutathione back to reduced glutathione.
3. Recycling of cysteine from conjugated glutathione, ready for further glutathione synthesis.
To increase reduced glutathione in the body:
• Decrease depletion of glutathione through reduction or avoidance of stress, smoking, processed foods, pesticides, exhaust fumes and excessive exercise.
• Increase levels through direct administration, such as topical liposomal cream, s-acetyl glutathione supplements, and in serious cases, IV glutathione, nebulized glutathione and intranasal glutathione.
• Use supportive nutrients that raise glutathione levels such as milk thistle, N-acetyl cysteine (NAC), Alpha Lipoic Acid (ALA), selenium, cordyceps, gotu kola and L-glutamine.
• Pay attention to diet and lifestyle activities that increase glutathione levels such as eating cruciferous vegetables, antioxidant-rich foods, moderate aerobic and strength exercises, and meditation.
Alongside optimising glutathione protection, there are several other factors that both reduce our exposure to heavy metals, and help to remove them from the body.
• Eat plenty of fibre from vegetables, pulses, nuts and seeds to help to carry the toxins out of the body and promote regular bowel movements, which is essential for ensuring the heavy metals are being excreted rather than recirculating and settling in other tissues.
• Stay hydrated by drinking at least 8 glasses of purified water every day to help flush out toxins and support healthy bowel function.
• Eat organic foods to avoid pesticide exposure.
• Limit intake of large oily fish such as tuna, large salmon and swordfish that are higher in mercury.
• Eat coriander and parsley regularly; both are thought to help remove heavy metals from the body. Add them to green juices/smoothies daily.
• Citrus pectin – a type of fibre thought to be helpful for clearing toxins such as heavy metals from the body.
• Chlorella – recent research has shown that chlorella is helpful for cadmium and lead detoxification.
• NAC is thought to clear mercury and lead through the urine and it increases the production of glutathione. Used orally it is very safe except in those sensitive to sulphur, in which case S-adenosylmethionine (SAMe) may be a better choice.
• Curcumin – is supportive because it decreases the oxidative damage from toxins.
Chelating agents are used to bind heavy metals and pull them out of the body, such as DMSA, which is taken by mouth as a tablet, and EDTA, which is administered through an IV or rectal suppository. They must be used under the guidance of an expert, due to possible side effects. DMSA appears to have the best safety and tolerance records especially when used carefully and slowly, although those sensitive to sulphur may react. Other supportive agents, such as ALA, vitamins C and E, probiotics and fibre used alongside DMSA can reduce cellular damage and increase the rate of toxin excretion. Replenishment with beneficial minerals alongside chelation is key because chelation can bind these minerals too and remove them from the body.
• Saunas – regular use can increase the excretion of arsenic, cadmium, lead and mercury through sweat. It is thought sweat is the best way to remove cadmium from the body.
• Hydrotherapy – a study in the UK found hydrotherapy increased the urinary excretion of lead by 250%.
• Enemas – can be used safely at home to ensure toxins are being excreted from the bowel effectively.
Written by Emma Rushe and Oliver Barnett