Lead, Arsenic, Aluminium, Mercury, Nickel and Cadmium: we have always lived alongside these metals but we have no biological need for them and some are toxic to life in all but the tiniest amounts. Unlike the minerals calcium, magnesium copper and zinc, which we evolved using – functionally – within, and as part of our physiology.

Along with many pesticides and petrochemicals, heavy metals (HM) are becoming widely distributed in our industrialised world and – crucially – we are ingesting, inhaling and absorbing them, which means we are storing them too, especially if we have inadequate detoxifying capabilities.   This slow accumulation within organs and various tissues can, over decades, have potentially deleterious health consequences for our nervous, vascular, endocrine and immune systems, which have all been shown to be adversely affected by toxic heavy metals.

The build up and storage of toxic elements can occur in various organs, joints or fatty tissues, if our detoxification ability is impaired or sub-optimal, which can be a consequence of a nutrient depleted diet, which fails to provide the necessary nutrient cofactors for phase I & II liver function.  Most HMs are toxic to the body, especially the brain and the endocrine system (hormones), where they can be attracted to certain proteins, and bind irreversibly.  If that protein happens to be an enzyme it will alter its ability to function, or if a hormone – it will affect its ability to bind to receptor sites – an essential function of hormones.

Mercury is probably the most abundant HM that we are exposed to and it comes in various guises.  Some people have concerns about eating regular or frequent portions of oily fish like salmon and Skip-Jack Tuna, but in fact mercury levels in these smaller fish are negligible, however the long-lived, large predators, like the Blue-fin Tuna and Swordfish can make a significant contribution to mercury ingestion when eaten regularly.  However, if we have healthy, abundant levels of gut microflora, they will trap and excrete some of this ingested mercury.  Of course gut microflora can get depleted with antibiotics, which then reduces this natural barrier in the gut lining.  Mercury that then gets absorbed goes to the liver for processing, but without the tools to effectively excrete it, mercury gets shunted off to various tissue sites around the body, to be stored.

Another route of exposure is inhalation.  Mercury is ubiquitous in the environment, coal fired power means our air is polluted and inhaled mercury vapour is more toxic than the ingested particle. The inhaled mercury vapour that occurs during dental amalgam removal can also be significant, and because the lungs do not have the capacity to detoxify this HM, its absorption and accumulation in many tissues can lead to oxidative damage, mitochondrial dysfunction and cell death.  ‘Teeth-grinders’ or ‘chewing-gum users’, who happen to have lots of amalgams can also be at risk, as oral mucosal tissue absorbs mercury particles over time which get taken up by cranial nerves in the mouth, and travels via nerve axions to the brain where it is stored, with a half life of over 30 years.

Another exposure of HM comes via vaccines, where it can be used as an ‘adjuvant’, i.e. added to the vaccine to irritate the immune system into reacting, to what is a dead virus, which the immune system would otherwise ignore.  Again, the mode of delivery – injected direct to the bloodstream – makes a HM more toxic, bypassing the normal filters provided by the digestive system.  Tetanus and Hepatitis B injections still have mercury adjuvants, but many others now have aluminium.  The switch reflected the belief that aluminium was less toxic than mercury, though the research underpinning this theory is somewhat flawed, meaning that aluminium adjuvant is likely delivering similar and detrimental health consequences as its predecessor Mercury.

So what are the health consequences?

HMs have a multi-system effect on the body – this much is beyond doubt.  Peer-reviewed medical journals such as the New England Journal of Medicine and the Journal of the American Medical Association have multiple articles and papers showing heavy metals affecting the entire vascular system, leading to Stroke, hypertension, heart attack and renal failure.  Other journals show implications for macular degeneration, thyroid disease, and cognition.  HM toxicity can accumulate slowly over time but the patients that are most chronically sick have often had the highest exposure and carry the worst toxic burden.

Review of recent literature suggests that mercury from dental amalgam may lead to nephrotoxicity, neurobehavioural changes, autoimmunity, oxidative stress, autism, skin and mucosa alterations or non-specific symptoms and complaints. The development of Alzheimer’s disease or multiple sclerosis has also been linked to low-dose mercury exposure.  Safe removal of dental amalgam has been shown to lead to permanent improvement of various chronic complaints in a relevant number of patients in various trials.

1) Endocrine system

All hormones show sensitivity to HMs and the hormone precursor DHEA is no exception, with knock-on effects for many downstream hormones.  When DHEA is sulphated to its stable, ‘storage’ form, it requires enzymatic action from glutathione, to reverse it back to its available precursor form again.  Unfortunately, in the presence of heavy metal toxicity, glutathione will prioritise clearing HMs and once bound to them – irreversibly – will get excreted along with the HM, (permanently losing some glutathione to the body), which results in depleted glutathione availability for the sulphating conversion of stored DHEA to its active form.  Less available DHEA means less steroid hormones.

The balance of female sex hormones can be affected through HMs having an affinity with progesterone.  A HM binding irreversibly with progesterone receptors will cause a reduction in progesterone activity, thereby indirectly causing oestrogen dominance, with uterine consequences like fibroids and uterine hyperplasia.  Testing serum levels of progesterone will most likely show normal levels, as it’s progesterone’s binding ability at the cellular level – at receptor sites – that’s being inhibited, not the production of the hormone as reflected in serum levels.

Methyl mercury, cadmium and lead can also induce a reduction of luteinising hormone.  Normal oestrogen levels can actually protect against these effects, but menopausal women can be vulnerable and at higher risk when falling oestrogen levels cause bones to shrink.  Bones over a lifetime can act as a repository for heavy metals, so lead stores and other metals get released with age-related bone and mineral loss.

Women with hormonal conditions like fibroids and severe PMS have shown the highest excretion of Mercury recorded.  Amalgams are not inert and a person’s Mercury levels will often correlate with quantity of amalgams.   The removal of them – if done without due care and consideration for their toxicity – can temporarily increase a person’s exposure.  However, safe and successful removal can actually recover previously blocked enzyme functions and restore good hormone levels. Where fertility issues are being investigated, chelation therapy can be a useful adjunct.  Amalgams were actually banned in Sweden in 1987, starting with the most vulnerable, children and pregnant women.

Arsenic has similar toxic potential to mercury, and can affect hormonal, metabolic and immune systems.  Primary sources of exposure are water, food, polluted air and pesticides, making a toxic aggregate potential for some.

2) Autoimmunity

The risk of autoimmune conditions increases when there has been significant HM exposure.  Mercury in the bloodstream can bind to any tissue, but commonly, tissue in the brain, thyroid, liver, gallbladder and the joints.  In this situation, the immune system responds by mounting an attack – a far more fierce attack than the sort used to achieve normal cell turnover and repair – so high levels of antibodies attack the mercury but unfortunately kill off surrounding tissue as collateral damage, and faster than the body can regenerate.

Mary Ellen Chalmers (Functional Medicine Dentist) believes amalgam removal and chelation of mercury burden should be considered when autoimmune conditions co-exist.

3) Kidney damage

Autopsies in America reveal that arsenic is prevalent and has an affinity with kidney tissue – causing nephritis, but arsenic has a very short half life in the human body, so its prevalence must reflect continual exposure.  Contaminated water supplies are believed to be the culprit, and some farmers add arsenic to chicken feed as an anti-parasitic.

4) ADHD & Autism

These conditions did not exist a century ago, and whilst their association with the now prevalent use of organophosphate pesticides is being hotly debated, their ‘disproven’ association with vaccines may in fact be shown to have some association after all, through the adjuvant HMs that are often used in many vaccines.  Certain genetic predispositions may have a heightened sensitivity to the adjuvant aluminium which when delivered as a multiple dose, delivers sufficient aluminium to cross a toxicological threshold not yet adequately studied.  This metal is also leaching from cooking pans, foils, antacids, anti-depressants, as well as pesticides on cereal crops.

5) Gut Dysbiosis

Glyphosate is in the common pesticide Roundup and complicates the picture further. Aluminium molecules are naturally ‘charged’ particles, but they can easily bind to glyphosate, and in so doing, make a x3 molecule ‘uncharged’ particle.  This is significant because whereas ‘charged’ particles are more easily blocked in the gut, ‘uncharged’ ones pass more easily and get absorbed across the gut lining.  So in the presence of glyphosate, aluminium becomes more potent and more easily absorbed.  And glyphosate, the active chemical in Roundup used on many food crops, has been shown to disrupt beneficial gut flora, causing gut dysbiosis and leaving favourable conditions for pathogenic levels of yeasts to flourish.

Similarly, the glyphosate ‘run-off’ from agricultural land, passing through lead piping, will leach and bind lead particles, exposing us to this toxic load via our drinking water.  Glyphosate is a very effective binder – it even binds dietary magnesium, zinc, iron and calcium, causing nutrient deficiencies as well as disrupting enzyme catalysts.

6) Brain health & Cognitive function

Mercury primarily affects neurological tissue, resulting in numerous neurological symptoms.  A growing number of researchers are now crediting the increase in neurological disease and cancer to glutathione deficiency, and glutathione gets depleted with heavy metal toxicity.  When the glutathione content of the body is depleted, it can give rise to the possibility of increased retention of other environmental toxins, and less antioxidant protection of DNA.

Boosting Liver function to combat HM toxicity

Genetic testing can be useful as an individual’s liver detox pathways and their ability to synthesise glutathione is governed by their genetics.  An individual’s genetic variants – SNPs – will influence the degree of accumulation and therefore toxic effects of any heavy  metals (HM).  Most people have one SNP in the methylation pathway, the presence of two will mean a higher proportion of HM is likely being stored rather than eliminated.  An accumulation of HM over time can push one over a critical threshold and the combination effect of possibly 2 or more different metals – even if in tiny amounts – often equals disproportionately greater toxicity – they tend to have a synergistically greater toxicity when combined.

Glutathione – produced in the liver – is the body’s innate master antioxidant.  A compound of three simple amino acids, (cysteine, glycine and glutamine), glutathione regenerates itself in the liver and is critical for the immune system’s first line of defence and keeping all sorts of pathologies at bay.   It is also essential for our mitochondria, those little energy packs in every cell of the body.  The power of glutathione lies in its ability to grab and hold on to free radicals and toxins (like mercury) in the body, it’s the master detoxifier, and its levels are notably low in seriously ill patients.

The body synthesises Glutathione via cysteine in the homocysteine pathway, so if a person is lacking B vitamins (through stress, alcohol or poor diet), and cysteine is also deficient, good levels of glutathione will not be synthesised effectively.  Diet is an obvious area to investigate if poor detoxifying ability is suspected as a mitigating factor resulting in high levels of stored heavy metals.  Magnesium can effectively block absorption of a certain amount of lead, but the dietary cofactors for methylation – B vitamins, iron, Mg and zinc – are crucial for the liver’s detoxification pathways generally, and are also fundamental to the clearance of HMs.

Lipoic acid is another protein that gets bound by heavy metals.  Lipoic acid is a crucial component of the Kreb’s Cycle, so if bound by exposure to heavy metals, this has implications for energy production and may be implicated in cases of Chronic Fatigue.  The supplement Alpha Lipoic acid has been shown to boost blood levels of glutathione. N-acetyl cysteine can also be a useful supplement, being a natural precursor.

Certain foods usefully assist our liver to produce glutathione: Whey protein boosts cysteine levels, and sulphur-rich foods like garlic, leeks and onions boost glutathione production, as do cruciferous vegetables like broccoli, kale, cabbage, brussel sprouts, cauliflower, radishes, bok choy and watercress.  The ‘methylation ingredients’ that support that liver pathway and keep the production levels of glutathione up are beans, liver, spinach, asparagus, avocado, beets and broccoli.

Glutathione in supplemental form tends to get degraded in the intestines making it less useful to the liver, the exception being Liposomal glutathione.  Milk Thistle helps increase glutathione levels and also helps to cleanse and regenerate the liver.  Antioxidants like vitamins C and E as well as Selenium, (found in Brazil nuts, sardines, halibut, turkey and eggs), help to recyle glutathione, and exercise will boost the innate production of glutathione, both aerobic and strength exercises.

References

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Rzymski P et al., (2015) Impact of heavy metals on the female reproductive system. Ann Agric Environ Med. 22(2):259-64. https://www.ncbi.nlm.nih.gov/pubmed/26094520 

Kim R et al., (1996) A longitudinal study of low-level lead exposure and impairment of renal function. The Normative Aging Study. JAMA 275(15):1177-81 https://www.ncbi.nlm.nih.gov/pubmed/8609685 

Lustberg M & Silbergeld E (2002) Blood lead levels and mortality. Arch Intern Med. 162(21):2443-9. https://www.ncbi.nlm.nih.gov/pubmed/12437403 

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Paul B Tchounwou et al., (2012) Heavy Metals Toxicity and the Environment EXS 101: 133–164.

Garrido M et al., (2011) Glutathione depletion and overproduction both initiate degeneration of nigral dopaminergic neurons. Acta Neuropathol. 121(4):475-85