This month let us explore the “dental connection to Alzheimer’s Disease.”

Two Hallmark Signs

Alzheimer ‘s disease (AD) is a devastating affliction which has profound impact not only on the individual affected but also on the entire family. As our population ages, more and more people are being diagnosed with AD. The cost to our country, in terms of stress and money, are extremely high. Wouldn’t it be wonderful if it could be prevented in a large number of those predicted to come down with the disease? This thought does seem difficult given the fact that AD can now only be definitively diagnosed upon autopsy.

However, the two hallmark signs upon autopsy that confirm the clinical diagnosis of AD, the presence of neurofibrillary tangles and amyloid plaques, have allowed scientists to find what may cause these anomalies.

Mercury Vapor and Effect on Microtubules

A nerve cell has a scaffolding type of skeletal structure composed of microtubules which is formed from tubulin. This skeletal structure is like a railroad bed that then allows the “tracks” or nerve fibers to be laid down. If you take away the tubulin, the nerve fiber is left unsupported resulting in the neurofibrillary tangles. In other words, destroy the tubulin and the nerve can no longer function. In a study done at the University of Calgary and published in March of 2001, in a peer reviewed medical journal, the researchers demonstrated on a snail neuron that mercury vapor in very minute concentrations destroys the microtubules. They also tested lead, aluminum, cadmium and manganese, but only mercury caused this hallmark sign of AD. However, this study is only one in a long line of research that implicates mercury in AD. Let us look at just a few of these important bodies of work.

Dr. Boyd Haley and his research on heavy metals

Much research has been done by Dr. Boyd Haley, former head of chemistry at the University of Kentucky. Back in the early 90’s, his lab demonstrated that tubulin had diminished biological activity in the postmortem AD brain – and only in the AD brain. Searching for a possible cause, they tested numerous heavy metals and found that only mercury could cause the tangles and amyloid plaques. Soon after this, Dr. Haley became aware that mercury composed half of all “silver fillings”. He was astounded that dentists were placing a substance as toxic as mercury in the mouths of their patients.

Dr. Haley then set out to see if mercury vapor, the form that escapes from dental fillings, could cause the same type of effect. To test this, he exposed rats to mercury vapor. The results showed the same detrimental effect on tubulin that is consistent with the changes in an AD brain. What is interesting to note, is that at first Dr. Haley gave the rats mercury laden drinking water for several months but found no change in the brain specimens. He then exposed the rats to mercury vapor in an amount that would for a rat, be equivalent to a human with several fillings. In a very short time, the rats had their tubulin destroyed.

Other heavy metals act to potentiate the effect of mercury.

Remember, the research has shown that only mercury affects the tubulin, not other heavy metals. Recent research in Dr. Haley’s lab has shown that other metals do have an effect – they potentiate the toxicity of mercury. Non-toxic levels of zinc and cadmium decrease the amount of mercury needed to interfere with tubulin. This would be more representative of a real-world situation – after all, one has exposure to many metals.

Amyloid Plaques

As stated earlier, another hallmark sign of AD is the presence of amyloid plaques. Research exploring this aspect of AD has shown that a minute amount of mercury exposed to nerve cells causes them to increase their secretion of amyloid protein. It is amyloid protein that makes up the amyloid plaque.

As a result of his findings, and the other research done around the world, Dr. Haley believes that it is reasonable to assume that mercury must be considered a major risk factor for AD, if not causal. So why haven’t we all been warned about this latest research in the fight against Alzheimer’s disease? Surely the ADA and other dental authorities have research to back up their claim that mercury from fillings has no relation to AD. However, it is interesting to note that these studies have not been published in any medical or scientific journals, but rather in the dental trade journals, General Dentistry and the Journal of the American Dental Association.

Mercury Vapor Coming Off Tooth Video
Smoking Teeth = Poison Gas. Video from

Remember it is scientific fact, that:

  • “Silver” fillings are approximately 40-50% mercury.
  • Mercury continuously comes out of the fillings in the lethal vapor form
  • Any stimulation to the fillings, i.e., chewing, grinding, drinking hot liquids, etc. increases the amount of vapor coming from the fillings.
  • Mercury from the fillings enters the body and builds up over time.
  • According to the World Health Organization, the major source of mercury burden in the body is from fillings, not food or the environment.
  • Mercury passes the placental barrier and accumulates in the fetus.
  • Mercury passes to the newborn via nursing.
  • The amount of mercury in the brain will directly relate to the number of fillings in the mouth.
  • There is no safe level of mercury in the human body.

With all that is known, how can dentists be allowed to keep implanting mercury in the mouths of their patients?

Not everyone with fillings will get Alzheimer’s disease – Gene Proteins

It is important to note, however, that not everyone with fillings will get Alzheimer’s disease. An important explanation for this may be found in research that deals with a gene protein called APO-E. It has been shown that there are four types of APO-E proteins. Those who have APO-E4 have a higher incidence of AD and early onset. Interestingly, those with APO-E2 and APO-E3 have much less likelihood of getting AD than those who have inherited the APO-E4 gene. What is the difference in these proteins? APO-E2 has two sulfur groups. APO-E3 has one sulfur group and APO-E4 has none. Remember, mercury loves sulfur (see my book, Whole-Body Dentistry, for more on this). There is a strong affinity between the two. The function of the APO-E is to transport unwanted materials out of brain cells; APO-E protein leaves the brain cells and goes into the Cerebral Spinal Fluid, crosses the blood brain barrier, then goes to the blood. The body then disposes the unwanted material.

Dr. Haley hypothesizes that APO-E 2 & 3 (with their sulfur) bind mercury as they leave the brain. APO-E4, not having any sulfur is not capable of doing this. Testing of these proteins may be a good idea for those worried if they are at risk for AD.


Read more: Dentistry and Alzheimer’s Disease – Part 1 we began our discussion of Alzheimer’s disease.

© 2004, Mark A. Breiner, DDS

The information presented is for educational purposes only. You should consult a qualified health practitioner for diagnosis and treatment.

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