How mercury causes major hallmarks of Alzheimer’s Disease

There are a number of very serious neurological disorders for which the cause is mysterious. The clinical pictures of several of these are most interesting when considered in light of the documented neurotoxicity of mercury and the potential for neurotoxicity from mercury/silver fillings.

Despite the protests of the FDA and the ADA, the science confirms that these fillings emit significant levels of neurotoxic mercury, and mercury is injurious to human health. This mercury from fillings would certainly exacerbate and probably is the cause of Alzheimer’s, Multiple Sclerosis, Parkinson’s, autism and ALS (Lou Gehrig’s Disease).


Chris Shade P.h.D. explains synergistic toxicity

The synergistic effects of mercury[5] with many of the toxicants commonly found in our environment make the danger of mercury unpredictable and possibly quite severe, especially any mixture containing elemental mercury, organic mercury, and other heavy metal such as lead and aluminum.


Mercury has been linked to Alzheimer’s disease by a number of different studies that have accumulated over the last two decades.




Richard Deth P.h.D. testifies to the FDA
about exposure to mercury vapor causing
Alzheimer’s Disease

The most recent was published in the Journal for Alzheimer’s Disease. The study performed a meta-analysis of 106 case-control or comparative cohort studies to associate mercury as a causative factor in Alzheimer’s disease. Noting that the main source of mercury in the human body is dental amalgam (1 – 27 ug a day)


In 1986, Ehmann reported that samples of AD brain analyzed by neutron activation had significantly elevated amounts of Hg in every area analyzed. In some areas such as the cerebellar hemisphere Hg levels were ten-fold greater in AD than controls (table 4).[6] The elevated Hg imbalance in AD brain was confirmed in a follow up studies by Thompson and others (1998).[7] Through cell fractionation, Wenstrup was able to trace the accumulation of mercury into the cell organelle called the mitochondria (1990).[8] Mitochondria are tiny organelles contained within cells that produce protein. These papers were all published in high quality scientific journals that were expert in reviewing such analytical data.

Later a paper was published in the Journal of the American Dental Association (JADA) that supposedly refuted these findings (Saxe 1995).[9] It should be noted that this publication in the JADA is in a journal with no expertise in reviewing the analytical chemistry or the neurology involved and has been highly criticized for its unwarranted conclusions.

Please read our article, Flaws in the Saxe Alzheimer’s Study, which discusses the many flaws of the Saxe Alzheimer’s study.

However, even in this paper, the mercury levels in the brains of Catholic nuns showed many of the Sisters had levels of mercury that would have to be considered toxic by any scientific standard. Why some nuns living in the same quarters and eating the same food had such elevated levels of mercury shows that it is most likely the ability, or inability, to excrete mercury places an individual at danger for retaining high mercury levels in the brain.


Boyd Haley P.h.D. explains
mercury induced oxidative stress

Mercury(II) or Hg2+, is neurotoxic and is known to be the most potent causation of oxidative stress, a biochemical state that is widely known to exist in Alzheimer’s disease and other neurological illnesses.


When exposed to normal brain tissue homogenates or neurons in culture Hg2+ (a/k/a, mercury(II) or mercuric mercury) is capable of producing many of the same biochemical aberrancies found in Alzheimer’s diseased (AD) brain. Rats exposed to Hg° vapor show some of these same abnormalities in their brain tissue. Specifically, the rapid inactivation of the brain thiol-sensitive enzymes (tubulin, creatine kinase and glutamine synthetase) occurs after: (a) the addition of low micromolar levels of Hg2+ (b) exposure to Hg° or, (c) the addition of Thimerosal (ethylmercurythiosalicylate sodium salt). Moreover, these same enzymes are significantly inhibited in the AD brain.


Researchers at the University of Calgary demonstrate how mercury causes
synaptic neurodegeneration by destroying
neuron growth cones

Exposure of neurons in culture to nanomolar levels of Hg2+ has been shown to produce three of the widely accepted pathological diagnostic hallmarks of AD. These AD hallmarks are elevated amyloid protein, hyper-phosphorylation of Tau, and formation of neurofibrillary tangles (NFTs).[10]


In 2001, the University of Calgary researchers, Leong, et al. produced a short video visually showing the disruption of tubulin-neurofibril interaction that represents how mercury, and only mercury, can cause synaptic neurodegeneration by destroying neuron growth cones. The cultured neurons exposed to low levels of mercury degenerated in a manner indicative of lesions observed in Alzheimer’s brain.[11] [12] This paper was omitted from FDA’s consideration because it is an in vitro study, but it is an important paper because it confirms the hypotheses of other papers. Leong supports the earlier reported Hg2+ specific destruction of the viability of brain tubulin.[13] Professor Boyd Haley concluded in 2003 that mercury and other blood-brain permeable toxicants that have enhanced specificity for thiol-sensitive enzymes are the etiological source of AD. Included in this category are other heavy metals such as lead and cadmium that act synergistically to enhance to toxicity of mercury and organic-mercury compounds.@[14] The demonstrated toxic synergy of mercury with other heavy metals is a concept completely omitted from consideration in FDA’s Final Rule.


Boyd Haley P.h.D. explains how mercury causes
3 of the major hallmarks of Alzheimer’s Disease

Haley found that mercury is the only heavy metal and apparently the only toxin of any kind that can cause many the biochemical abnormalities found in AD brain. The demonstrated synergistic potentiating of mercury toxicity by other heavy metals (lead, cadmium, silver, etc.) explains why a direct correlation between mercury levels alone and severity of AD-like braindamage has not been demonstrated.


Studies done on about five hundred sets of identical twins from WW II veterans show that AD is definitely not a directly inherited disease, as it requires a toxic insult.[15] Certainly, all the information and scientific studies point to toxin(s) as the major cause of AD. Ely confirmed substantial release of mercury from in situ amalgams and estimated the AD population would grow from its 2001 level of 4 million soles to 14 million soles based upon population age alone.[16] This enormous increase will devastate any health care system as cost of providing for even the 4 million AD patients at present dwarfs the total cost of dental care.


Boyd Haley P.h.D. explains the link between
APOE4 and genetic susceptibility to mercury toxicity

Haley, et al., detailed why the apolipoprotein-4 (APOE-4) genotype represents a genetic susceptibility to mercury toxicity as a pathogenetic factor and a moderator of AD.[17]


Mutter also demonstrates that persons of African descent have a much higher level of the susceptible APO-E4 gene. This may explain why AD is more prevalent in those with an African heritage.

In 1997, APO-E4 was identified as a significant risk factor for early onset of Alzheimer’s with APO-E2 being identified as protective against AD.[18] Several subsequent papers failed to clarify the reason. APO-E has 299 amino acids with different ratios of cysteine and arginine at position 112 and 158. APO-E2 has 2 cysteines, apo-E3 one cysteine and one arginine, and APO-E4 two arginines.[19] As arginine, unlike cysteine, lacks the sulphydryl (SH) groups to potentially bind bivalent metals such as mercury, lead, copper or zinc, it would be logical to suspect the possibility of increased metal accumulation in those chronically exposed individuals who had not inherited APO-E2. Godfrey 2003 found there was a statistically significant increase in adverse effects in those patients having APO-E4/4 and APO-E 3/4 where those patients were chronically exposed mercury. Godrey went on to explain why this occurs:

According to Saunders, the underlying reason for the apo-E-associated differences in AD susceptibility remains a mystery. However, a logical biochemical explanation has been proposed by Pendergrass and Haley, based on the different amino-acid configurations of the three apo-E isomers and their potential relevance to mercury elimination. Only ε2 (with two cysteine -SH groups), and to a lesser extent ε3 (with one –SH group), are able to bind and remove mercury from the brain and cerebrospinal fluid. This would oppose accumulation of mercury which is reported to be causal for the unique brain lesions that typify the AD brain including neuro-fibrillary tangles.

Godfrey added:

Another aspect of AD pathology is the evidence that enhanced mitochondrial damage occurs in AD and ε4 genotype. Mercury is very destructive at the mitochondrial level where catalase can demethylate organic mercury species into highly reactive inorganic mercury. Inorganic mercury is also an extremely potentenzyme inactivator. Furthermore, chronic micro-mercurial toxicity specifically from dental amalgam has been documented and successfully treated by removal of amalgam and medical detoxification in 796 patients.

Still, not all research results agree with mercury’s causal role in AD. Elevated mercury was not found in seven different regions of AD brains compared to controls. However, the “controls” had possessed three amalgam surfaces whereas the AD subjects had six, likely obscuring any differences. Saxe et al. reporting on the mental health of 129 nuns, found no difference between those with amalgam and controls. However, 72% of the controls had no posterior teeth, and the remainder had a mean of only three teeth. All 129 could, therefore, have had a similar previous amalgam history and the half-life of mercury in the brain is measured in decades. This paper’s conclusions, published in a dental trade journal, are at variance with those of another paper in the same journal on risk factors affecting dentists’ health. The authors identified 3 factors with equally highs tatistical values (i.e. p< 0.001), namely, a mercury spill in the dental office,manual amalgamation, and the dentists’ own amalgam status.[20]

Wojcik’s research (2006) supported a correlation between a genetic inability to eliminatemercury when the APO-E4 allele has been inherited and an increased incidence of commonsymptoms and signs of chronic mercury toxicity.[21] Thus the increased likelihood of AD inAPO-E4 is almost certain to be because of exposure to mercury, already known to be a powerful neurotoxin. Wojcik 2006 stated:

Two very important brain nucleotide binding proteins, tubulin and creatine kinase(CK), showed greatly diminished activity and nucleotide binding ability in the ADbrain tissues versus age-matched control brain samples.[22] Both tubulin and CKare proteins that bind the nucleotides GTP (guanosine-5’-triphosphate) and ATP(adenosine-5’-triphosphate), respectively.

After testing numerous heavy metals, we observed that, in the presence of EDTA,or other natural organic acid chelators, only Hg2+ mimicked the biochemicalabnormalities observed for tubulin in the AD brain homogenates examined. This was first done by adding low amounts of Hg2+ and other toxic heavy metals to homogenates of normal brain tissue in the presence of various metal chelators. Theobservation was that Hg2+ at very low micromolar levels (≅ 1 micromolar) couldrapidly and selectively disrupt the GTP or [32P]8N3GTP binding active-

Additional articles link mercury to Alzheimer’s Disease.[23] [24] [25] [26] [27] [28] [29] [30][31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43]

With the weight of the evidence there can be little doubt that mercury more likely than not causes AD and certainly would exacerbate this disease. Certainly, FDA’s Final Rule completely fails to address, much less refute, the concerns raised by this existing research.


Boyd Haley P.h.D. explains how the NIH
stopped his funding after proving
mercury causes 3 of the major hallmarks
of Alzheimer’s Disease

NIH refuses to fund studies that may compromise its–and FDA’s–long-held (but scientifically unsupported and unsupportable) claims touting the safety of amalgams. Specifically, NIH has improvidently refused to consider mercury exposure as the cause of AD, This is done, in the opinion of many, to protect industrial interests in developing a drug to treat elevated beta-amyloid conditions.


Perhaps in the near future, with help from international researchers, Alzheimer’s disease will be renamed, “mercury induced dementia.”



[5] Schubert, et al., “Combined Effects in Toxicology—A Rapid Systematic Testing Procedure:Cadmium, Mercury & Lead.” J. of Toxicology & Environmental Health, 4:763 (1978).

[6] Ehmann, W.D. et al., Application of Neutron Activation analysis to the Study of Age RelatedNeurological Diseases, Biol Trace Elem Res. 13:19-33 (1987).

[7] Thompson, et al., Regional Brain Trace-element Studies in Alzheimer=s Disease,Neurotoxicology, 9(1):107 (Spring 1988); Vance, Trace Element Imbalances in Hair and Nailsof Alzheimer=s Disease Patients, Neurotoxicology, 9(2):197-208 (Summer 1988); Cornett, etal., Imbalances of Trace Elements Related to Oxidative Damage in Alzheimer=s Disease Brain,Neurotoxicology, 19(3):339-45 (June 1998).

[8] Wenstrup, et al., Trace Element Imbalances in Isolated Subcellular Fractions of Alzheimer=sDisease Brains, Brain Res, 12;533(1): 125-31 (Nov. 1990).

[9] Saxe SR, et al., Dental amalgam and cognitive function in older women: findings from thenun study. J Am Dent Assoc. 1995; 126:1495–1501.

[10] Haley, B.E., The relationship of the toxic effects of mercury to exacerbation of the medicalcondition classified as Alzheimer=s disease, Medical Veritas 4 (2007) 1510B1524.

[11] How Mercury Causes Brain Neuron Degeneration (video)

[12] Leong C.C.W., Syed N.I., Lorscheider F.L., Retrograde Degeneration of Neurite MembraneStructural Integrity of Nerve Growth Cones Following in vitro Exposure to Mercury NeuroReportVol. 12 #4, 2001.

[13] Pendergrass, J. C. et al, Mercury Vapor Inhalation Inhibits Binding of GTP to Tubulin in RatBrain: Similarity to a Molecular Lesion in Alzheimer=s Disease Brain. Neurotoxicology 18(2),315‑324 (1997).

[14] Haley, B., The Relationship of the Toxic Effects of Mercury to Exacerbation of the MedicalCondition Classified as Alzheimer=s Disease, The Nordic Journal of Biological Medicine (June-July 2003).

[15] Breitner, J.C.S., et al., Alzheimer’s disease in aging twin veterans. III. Archives of Neurology,52:763-771 (1995).

[16] Ely, J.T.A., Mercury Induced Alzheimer’s Disease: Accelerating Incidence?, Bull EnvironContam Toxicol (2001) 67(6):800-806.

[17] Mutter, Alzheimer Disease: Mercury as a Pathogenetic Factor and as a Moderator,Neuroendocrinol Lett. 2004; 25(5):275-283 (AInorganic mercury (found in dental amalgam) mayplay a major role [in the pathogenesis of Alzheimer=s Disease.@])

[18] Roses AD and Saunders AM. Apolipoprotein E genotyping as a diagnostic adjunct forAlzheimer’s disease. Int Psychogeriatr. 1997; 9 (Supp. 1):277–288 and 317–321.

[19] Brouwer DA., Clinical chemistry of common Apoprotein isoforms. J Chromatography BBiomed Applic. 1996; 678 (1):23–41.

[20] Godfrey ME, Wojcik DP, Krone CA., Apolipoprotein E genotyping as a potential biomarkerfor mercury neurotoxicity. J Alz Disease 2003; 5:189–195.

[21] Wojcik,et al., Mercury toxicity Presenting as chronic fatigue, memory impairment anddepression: Diagnosis, treatment, susceptibility, and outcomes in New Zealand generalpractice setting (1994-2006) Neuro Endocrinol Lett 2006;27 (4):415-423.

[22] Khatoon S, et al., Aberrant GTP β-tubulin interaction in Alzheimer’s Disease. Annals ofNeurology 1989;26:210–5. David S, Shoemaker M, Haley B. Abnormal properties of creatinekinase in Alzheimer’s Disease brain: correlation of reduced enzyme activity and active sitephotolabeling with aberrant cytosol-membrane partitioning. Molecular Brain Research1998;54:276–87. Duhr EF, Pendergrass JC, Slevin JT, Haley B. HgEDTA complex inhibits GTPinteractions with the E-Site of brain β-tubulin. Toxicology and Applied Pharmacology 1993Oct.;122(2):273–88.


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