Mercury Damage Revealed by Brain Test

For several years I have been doing simple daily tests to measure my brain function. I got the idea when I noticed that a few capsules of flaxseed oil improved my balance. Flaxseed oil also improved other measures of brain function, such as digit span. I wasn’t surprised I could do better; what was surprising was how easy it was. It revealed a big gap in our understanding of nutrition. I do the daily tests not only to improve brain function but also to improve the rest of my body. I think the brain is like a canary in a coal mine — especially sensitive to bad environments. Learning what environment was best for the brain would suggest what environment is best for the rest of the body. When I started taking an optimal amount of flaxseed oil, my gums turned from red (inflamed) to pink (not inflamed), supporting this assumption.

I tried six or seven mental tests and eventually settled on a test of arithmetic (how fast I could do simple problems such as 5-3). I hoped that now and then my score would change (in either direction, faster or slower) and that these changes would point to new things that control brain function. No one had/has done such a thing. I had no idea if unexpected changes would show up or, if they did, how often. I didn’t know what the score changes would look like (their size and shape) nor, of course, what would cause them. Would all of them involve diet? Would all of them make sense in terms of what we already know? (Flaxseed oil makes sense because the brain contains lots of omega-3.)

The first two surprises were these: 1. My score suddenly improved a few days after switching from Chinese flaxseed oil to American flaxseed oil. This made sense: It is easy to destroy omega-3 if flaxseed oil is kept at room temperature. 2. My score suddenly improved when I switched from pig fat to butter. This was counter-intuitive: pig fat is more paleo than butter.

Last fall, there was another surprise: My score greatly improved since the summer. I was much faster than ever before. At first I thought the improvement was due to moving to Beijing. I had moved from Berkeley to Beijing in early September.  My Beijing life differed in a thousand ways from my Berkeley life. I had three ideas about which differences might matter. 1. Walnuts. Perhaps I ate more walnuts in Beijing. Walnuts are supposed to be good for brain function. 2. Heat. It was much hotter in Beijing than Berkeley. Maybe that improved brain function. 3. Vitamins. I took less vitamin supplements in Beijing. Maybe they harmed brain function.

I tested these possibilities. 1. I stopped eating walnuts. My arithmetic score did not clearly change. 2. Winter came, it got much colder. The improvement did not go away. 3. I took the same amount of vitamins I’d taken in Berkeley. My arithmetic score didn’t change. So all of these ideas were wrong.

Because they were wrong, I considered a fourth possibility: The improvement was due to removal of two mercury amalgam fillings on July 28, 2010. They were replaced with non-amalgam fillings. I’d had them removed for precautionary reasons. I wasn’t suffering from any signs of mercury poisoning. Hair tests had repeatedly shown mildly high amounts of mercury in my hair (75th percentile of an unspecified sample). Measurements of the mercury in my breath had come out higher than usual but it was hard to be sure the machine was working correctly.

I looked again at my data. It showed something I hadn’t noticed: the improvement started before I went to Beijing. It started very close to July 28. That was good evidence that the mercury explanation was correct. Now the evidence is even stronger. I’ve returned to Berkeley and thereby made my life quite similar to the situation when my scores were much higher than now. The improvement has remained.

The evidence for causality — removal of mercury amalgam fillings improved my arithmetic score — rests on three things: 1. Four other explanations made incorrect predictions. 2. The improvement, which lasted months, started within a few days of the removal. Long-term improvements (not due to practice) are rare — this is the only one I’ve noticed. 3. Mercury is known to harm neural function (“mad as a hatter”). As far as I’m concerned, that’s plenty.

A long Wikipedia article describes evidence on both sides of the question of whether mercury amalgam fillings cause damage. In 2009, the American Dental Association stated in a press release “the overwhelming weight of scientific evidence supports the safety and efficacy of dental [mercury-containing] amalgam.”  As recently as 1991, Consumer Reports told readers “if a dentist wants to remove your fillings because they contain mercury, watch your wallet.” (Dental insurance will pay most of the cost of removing my remaining amalgam fillings.) In an essay last revised in 2006, Stephen “Quackwatch” Barrett explained at length why mercury toxicity is a “scam”. According to Barrett, “there is overwhelming evidence that amalgam fillings are safe.”

Ask your dentist some pointed questions.










21 Replies to “Mercury Damage Revealed by Brain Test”

  1. After reading some studies of Jarmila Prochazkova (notably pubmed 16804512, 15349088 and 12743535), I decided to have my 11 amalgams removed. Where I live (Brazil) there are no dentits specialized in safe amalgam removal.

    Before the extraction, my thyroid antibodies (anti TPO) were decreasing while following a gluten free paleo diet. But somewhat stabilized around 400 UI/ml. Fifteen days after extraction, my tpo jumped to 454, then peaked 505 after 3 months, and then started to decrease. Only after 6 months, it returned to 400. During all this time, I was supplementing with chrorella, cilantro, vitamin c, high dose iodine and selenium.

    Unfortunatly, I started to eat fish (cod) twice a week, and that rised, again, my antibodies. Now, amalgam and fish free, I can say that I’m in the right track to overcome my autoimmune condition.

  2. Hey Seth, did you take any precautionary supplements or steps before or after the removals?

    The info on how and if to remove amalgams seems way to convoluted, It would be nice to find more successful detailed stories. There just doesn’t appear to be any referenced and creditable resources of science plus testimonials. Any thoughts?

    Thanks for all you do!

    1. I didn’t take any precautionary supplements or steps before or after the removals.

      Re the absence of “referenced and credible resources of science plus testimonials”. There is credible evidence amalgam fillings are dangerous; that is why they have been banned in several countries. You seem to be focusing on what is missing (“more successful detailed stories”) but I suggest you pay more attention to what is present — the evidence implying amalgams are dangerous.

  3. I had read about this a long time ago, but did not want to get my fillings removed because I had read that this could be dangerous too, by releasing more Hg during the removal. And I did not know of a dentist who would remove them anyway.

    So I was pleasntly surprised a couple of years ago when my dentist told me I needed a filling replaced and he was going to use some kind of space age plastic resin. I asked why, and he said that he thought the Hg amalgam might be unhealthy, and there was finally something that was sturdy enough to use instead.

  4. Seth, sorry if this is off-topic, but have you checked whether fish oil has the same positive effects for you (or other people) as the flaxseed oil? I’m wondering whether omega-3 oils are somewhat interchangeable, or whether there’s something special about flaxseed oil. Thanks.

    1. Jonathan, I tried fish oil once. It gave me a headache, so I’ve stuck with flaxseed oil. However, other people report the same effects (as I get with flaxseed oil) with fish oil.

  5. Seth – Have you considered another confounding factor that is living in the new city (Beijing) with the worst air quality – bar none?
    Additionally, your score is expected to improve over time from repeated cognitive exercise.

  6. As I understand it, mercury is very persistent in the body. So removing amalgam fillings can’t be expected to have an effect on your mercury levels for a long time. Hence, it seems very implausible that removing your fillings had any effect on brain function a few days later.

  7. Hi Seth,

    I’ve been wanting to remove my amalgam fillings for quite some time now.

    But I haven’t found a dentist who had something that I trusted as a safe replacement. Most composites contain either bisphenol A or nanoparticles. And polymerisation of the composites is never 100%, so there could be stuff leaking into your body, if I’ve understood well.

    I’m interested in any info on fillings that seem safe to you!

  8. Most likely he used a composite that includes bisphenol A – supposedly the levels that leech from it are minimal and safe, but then that’s what they say about mercury amalgams too. On the other hand, maybe bisphenol A is improving your brain function – it’s the other thing that changed at the same time as the removal of mercury.

  9. If it’s really mercury, then there should also be a measureable effect in individuals with mercury filings who just eat a lot of coriander/cilantro as that’s supposed to chelate the metals out of the body and into the urine..

  10. Seth,

    Is your dentist a ‘regular’ dentist or a ‘holistic’ dentist? Many anti-amalgamists claim there is special training required to safely remove amalgams.

    How much does it cost to have amalgams replaced? I’m trying to find out if the holistic folks charge significantly more than a regular dentist would, but Google isn’t turning up much, because most folks don’t like to list costs online.

    1. My dentist, Sandor Hites, is a holistic dentist. I recently had 3 fillings replaced. Two of them cost $260 each; the third cost $339. I don’t know why the price varied. My dental insurance paid 70%.

  11. Also, have you repeated the Doctor’s Data hair test before and after the amalgam removal on your new hair growth to compare mercury pre- and post?


  12. I had a mouthful of amalgams (12+) removed last fall at the insistence of my functional medicine doctor, and my autoimmune (Hashimoto’s) symptoms are finally improving. My endocrinologist has been fiddling with my medicine for years, but they never helped. I’m a believer.

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