Normal concentrations of heavy metals in autistic spectrum disorders.

27 Feb

A recent study once again looks for metals in autistic children. Once again fails to find significant differences between lead, mercury, cadmium and aluminum levels in autistic and non-autistic children. The study is relatively small (17 autistic children, 20 non-autistic). This group tested hair, blood and urine.

Here is the abstract:

Normal concentrations of heavy metals in autistic spectrum disorders.
Albizzati A, Morè L, Di Candia D, Saccani M, Lenti C.
Source
Operative Unit Child Neuropsychiatry A.O. San Paolo Hospital, University of Milan, Milan, Italy – carlo.lenti@unimi.it.
Abstract
AIM:
Autism is a neurological-psychiatric disease. In the last 20 years we witnessed a strong increase of autism diagnoses. To explain this increase, some scientists put forward the hypothesis that heavy metal intoxication may be one of the causes of autism. The origin of such an intoxication was hypothesised to be vaccines containing thimerosal as antimicrobic preservative. This preservative is mainly made up of mercury. The aim of our research was to investigate the correlation between autism and high biological concentrations of heavy metals.
METHODS:
Seventeen autistic patients, between 6 and 16 years old (average: 11.52 DS: 3.20) (15 males and 2 females), were investigated, as well as 20 non autistic subjects from neuropsychiatric service between 6 and 16 years (average: 10.41 DS: 3.20) (15 males and 2 females). In both groups blood, urine and hair samples were analysed trough means of a semiquantitative analysis of heavy metal dosing. The metals analysed were Lead, mercury, cadmium and aluminium, since their build-up may give both neurological and psychiatric symptoms.
RESULTS:
The comparison of the mean values of the concentrations between the groups, performed with ANOVA test, has shown no statistically relevant differences.
CONCLUSION:
There wasn’t correlation between autism and heavy metal concentration.

This follows on the heels of a recent study published in the Public Library of Science, A Comparison of Urinary Mercury between Children with Autism., which found no differences in urine concentrations of mercury. This study was discussed here at Left Brain/Right Brain.

Looking back, what other studies have there been?

Heavy Metal in Children’s Tooth Enamel: Related to Autism and Disruptive Behaviors?

The current findings challenge the notion that perinatal heavy metal exposure is a major contributor to the development of ASDs and HDB [highly disruptive behaviors]

Lack of Correlation Between Metallic Elements Analyzed in Hair by ICP-MS and Autism.

A cross-sectional case-control study was carried out to evaluate the concentrations of metallic elements in the hair of 44 children with diagnosis of autism and 61 age-balanced controls. Unadjusted comparisons showed higher concentrations of molybdenum, lithium and selenium in autistic children. Logistic regression analysis confirmed the role of risk factor for male gender and showed a slight association with molybdenum concentrations. Unconventional chelation and vitamin-mineral supplementation were ineffective on elemental hair concentrations. A meta-analysis including the present and previous similar studies excluded any association of autism with hair concentrations of mercury, cadmium, selenium, lithium and copper. A slight association was found for lead only, but it was very weak, as strictly dependent on the worst data from one study.

Blood mercury concentrations in CHARGE Study children with and without autism.

After accounting for dietary and other differences in Hg exposures, total Hg in blood was neither elevated nor reduced in CHARGE Study preschoolers with AU/ASD compared with unaffected controls, and resembled those of nationally representative samples.

IMFAR (unpublished) abstracts:

Prenatal and Neonatal Peripheral Blood Mercury Levels and Autism Spectrum Disorders

Conclusions: Levels of total mercury in serum collected from mothers during mid-pregnancy and in blood collected from infants at birth were not associated with risk of ASD.

The Tooth Fairy Project: Heavy Metal Concentrations in the “Baby Teeth” of Children with Autism Spectrum Disorders (ASD)

Results: Initial analyses do not indicate higher concentrations of lead, manganese, or mercury in either prenatal or postnatal regions of the teeth among children with ASD as compared to matched controls. The presentation will include final analyses and interpretations on the full sample and on other elements.
Conclusions: Based on preliminary results, concentrations of heavy metals do not seem to be higher in children with ASD. The type of biomarker used may be important, and it is also possible that prenatal and early postnatal exposure to heavy metals contributes to the development of ASD in some children, but not others.

PS1.65 MERCURY LEVELS IN CHILDREN WITH PDDS AND THEIR MOTHERS: A CASE-CONTROL STUDY

Conclusion: There is no evidence that children with PDD have elevated levels of mercury or that they have deficiencies in mercury excretion. The findings do not support the use of chelation therapies as a treatment of autism.

PS3.36 A STUDY OF MERCURY LEVELS IN YOUNG CHILDREN WITH AUTISM USING LABORATORY ANALYSIS OF HAIR SAMPLES

Analysis of hair sample data by t-tests for equality of means and equal variance yielded no significant difference in mercury levels for the two groups. Despite the small sample size, results raise questions about the usefulness of evaluation for mercury exposure using hair samples, and about claims of mercury toxicity in children with autism.

PS6.4 NO AUTISM AMONGST INUITS FROM NORTHERN QUEBEC?

Conclusion: Autism appears to not exist amongst Inuits from Northern Quebec. If confirmed, it would have significant implications for the genetic understanding of autism. In addition, as Inuits are exposed through their fish-eating practices to high pre- and post-natal levels of mercury, it would also suggest that high mercury exposure in itself does not increase the risk of autism.

24-hour provoked urine excretion test for heavy metals in children with autism and typically developing controls, a pilot study.

RESULTS:

Fifteen autistic children and four typically developing children completed the study. Three autistic subjects excreted one metal in greater quantity during the provoked excretion than baseline. Two of these were very close to the limit of detection. In the third case, the provoked excretion of mercury was between the upper limit of normal and lower limit of the potentially toxic reference range. Fish was removed from this child’s diet for greater than one month, and the provoked excretion test repeated. The repeat excretion of mercury was within the normal range.
CONCLUSION:

In the absence a proven novel mode of heavy metal toxicity, the proportion of autistic participants in this study whose DMSA provoked excretion results demonstrate an excess chelatable body burden of As, Cd, Pb, or Hg is zero. The confidence interval for this proportion is 0-22%.

Yes, you can find papers claiming there are differences in hair, blood or urine concentrations of mercury. Many by father-son team Mark and David Geier. I won’t take the time to go into the lengthy discussion of why I don’t trust anything they do without corroboration. There is the old Amy Holmes “baby haircut” study that was taken apart at the autism omnibus proceeding (amongst other places). Plus a couple papers by James Adams. Yes, and a poorly done reanalysis of an existing dataset. Just not a strong body of evidence to support the idea that “autism is a novel form of mercury poisoning”.

In the end all of this evidence comes in a far second to the fact that multiple studies have shown no increased risk for mercury exposure from vaccines. For example:

[Lack of association between thimerosal-containing vaccines and autism].

Our study revealed no evidence of an association between TCVs and autism.

So much time spent. So much money spent. And it is still going on. It’s long past time to move on. The vast majority of the research community already has. Most parents have.

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19 Responses to “Normal concentrations of heavy metals in autistic spectrum disorders.”

  1. MikeMa February 27, 2012 at 20:32 #

    I see folks with shovels coming to dig up and move the goalposts. Any chance of replicating this work on a larger scale to settle it more definitively?

  2. Oh come on February 29, 2012 at 00:17 #

    What does that metaphor even mean? They tested for correlation and no correlation between autism and heavy metals were found. Seems like someone is using flowery wording to escape admitting to a delusion.

  3. Science Mom February 29, 2012 at 01:09 #

    What does that metaphor even mean? They tested for correlation and no correlation between autism and heavy metals were found.

    What metaphor are you referring to? I don’t understand your complaint.

  4. MikeMa February 29, 2012 at 01:45 #

    @Oh come on,
    If the metaphor you are referring to is my goalposts one, I am anticipating the heavy metal fans on the anti-vax sites looking for reasons to ignore or ridicule the study. One way would be to point out that it was, as Sullivan said, rather small. Another might be the Pharma conspiracy gambit where the loons will discount the results because big pharma paid for some or all of it.
    Otherwise I am as confused as Science Mom.

  5. RAJ February 29, 2012 at 01:54 #

    I have for decades managed the logical design of complex IT systems and when I look at these studies I shake my head. They are all based on the false assumption that all humans have the same response to any environmental pathogen. Comparing affected to unaffected group on the level of exposure cannot control for GxE or epigenetic effects.

    I’ll give this example, for many years AIDS researchers wondered why some individuals get infected after one exposure to HIV-1 and other individuals appear to be resistant to infections even after dozens of HIV-1 exposures.
    A meta-analysis demonstrated how common genetic variants in the CCL3L1 (17q11-12) gene has both risk and protective effects with respect to HIV/AIDS susceptibility. Compared to population norms, lower copy numbers in the CCL3L1 gene substantially increases risk for infection after exposure. However, higher copy number variations in the CCL3L1 gene confers resistance to infection after exposure to HIV-1 (Lui et al 2010 ).

    http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0015778

    Here’s another study. Stanley et al published the first study to show that fever after smallpox vaccination is associated with specific gene clusters in the interleukin-1 (IL-1) gene complex on chromosome 2 and the interleukin-18 gene on chromosome 11.

    As was the case with was AIDS research, gentic variations were associated with reduced risk, no risk and and increased risk dependant on the specific gene variation.

    http://jid.oxfordjournals.org/content/196/2/212.long

    So what can one make of these studies. They can’t prove or disprove that exposures to environmental pathogens are associated with or not associated with risk based on the false assumption that all humans have the same risk for any disease depending solely on equal exposure in affected and unaffected individuals.

    • Sullivan February 29, 2012 at 01:59 #

      RAJ,

      don’t pull credentials around here. Your track record should (and does) speak for itself when it comes to your powers of deduction.

    • Sullivan February 29, 2012 at 03:01 #

      “They are all based on the false assumption that all humans have the same response to any environmental pathogen.”

      You should check your logic and assumptions. The studies are not based on that assumption. If they claimed, “this shows autism is not caused by mercury” you would be accurate. But they don’t. They say that the results don’t support such a link. Conclusion for the main study above? “There wasn’t correlation between autism and heavy metal concentration.” How, exactly, does that assume that all humans have the same response to heavy metals?

      I’d be interested if you can you point me to your comments, say, five years ago where you made the same claims about how studies of mercury concentrations in blood, urine, hair, nails, etc, are not valid indicators? Say after the Holmes baby haircut study or after the DeSoto reanalysis of the Ip data?

      The fact is that the claims were made that autistics have different amounts of heavy metals (usually mercury) in their hair, blood, urine, etc.. Studies such as the ones above show that the “evidence” that was mounted to make the claim that autism is caused by mercury are false claims.

      Consider the legs of the “autism is caused by mercury poisoning” argument.

      “there’s an epidemic of autism which correlates with the increased exposure to mercury from vaccines”
      The increase in autism rates was not due to mercury in vaccines.

      “Autistics are poor extreters of mercury as shown by hair/blood/urine/etc. concentrations of metals”
      Autistics do not show signs of being “poor excreters of mercury”

      “Autism is a novel form of mercury poisoning”
      Autism and mercury poisoning do not share the same symptoms

      “Chelate your kid for 2 years and you “get him/her back” ”
      Chelating autistics does not “reverse” autism.

      What other legs does the hypothesis have to stand on? Well, there’s the porphyrin tests (which rely upon comparing to “normal” controls, something you just said isn’t accurate)

    • Sullivan February 29, 2012 at 03:55 #

      Sorry for the repeated responses:

      “…the false assumption that all humans have the same risk for any disease depending solely on equal exposure in affected and unaffected individuals.”

      You don’t appear to understand the meaning of risk in this context. Risk is an ensemble risk, not an individual risk. A person, on average, would have a risk of a certain outcome is not the same thing as saying that the average person has exactly that risk ratio.

      You bring in the example of HIV. Had epidemiologists said, “everyone has the same risk of contracting HIV/AIDS” back in the 1980s, we wouldn’t have learned the methods of transmission. People didn’t just stumble upon the reasons for reduced risk that you cite, either. There were reason they studied these sub populations.

      After all this time, do you really believe that there is a assumption (false or not) that “that all humans have the same risk for any disease depending solely on equal exposure in affected and unaffected individuals.”? It is such a seriously flawed statement as to make me wonder why you would put it forth. Clearly you have the ability to see that for the false statement it is.

  6. MikeMa February 29, 2012 at 02:04 #

    @RAJ,
    Isn’t that the reason for wanting significantly larger studies so that those differences can be accounted for accurately or dwarfed?

  7. Cindy March 1, 2012 at 10:55 #

    Can these afore mentioned metals/toxins also be a cause for ADHD? (E.g. found in the following articles: https://www.grin.com/login/#documents/184126/text and http://blog.adhs-ernaehrung.com/2011/05/30/blei-verursacht-adhs/)

  8. RAJ March 1, 2012 at 11:48 #

    Sullivan;
    I thought you would get all wee-weed up at any suggestion that there is a strong environmental component in autism. You are on the wrong side of history with your continued love affair with the behavioral geneticists and genetic determinists who have followed an autism model as a heritable genetic disorder.
    Sir Michael Rutter is widely known as the father of modern child and adolescent psychiatry and served as the European editor of the Journal of Autism and Developmental disorders before retiring. He has now described the behavioral geneticists you admire so much as rapidly becoming extinct and the behavioral geneticists reject the environmental component as an ‘irritant to be ignored’ and as a group refuse to accept the reality of GxE.
    This is rapidly changing. The SFARI Autism group is now increasingly reporting on the environmental component in autism. The SFARI Autism group was originally founded on the concept that autism is a genetic inherited condition.

    Here:

    http://sfari.org/news-and-opinion/news/2012/sequencing-identifies-source-of-mitochondrial-disorders

    Here:

    http://sfari.org/news-and-opinion/in-brief/2012/clinical-research-autism-genes-linked-to-autoimmune-disease

    Here:

    http://sfari.org/news-and-opinion/autism-in-the-arts/2012/book-review-autisms-twisted-immune-links-untangled

    Here:

    http://sfari.org/news-and-opinion/in-brief/2012/cognition-and-behavior-contaminant-acts-with-autism-gene

    A recent article published by SFARI Autism discussed the new finding that advanced paternal was seen in girls with autism and de novo gene mutations.

    You can view the article and comments section that discuss the reasons and causes of the association here:

    http://sfari.org/news-and-opinion/news/2012/effect-of-paternal-age-seen-in-girls-with-autism

    • Sullivan March 1, 2012 at 22:25 #

      I thought you would get all wee-weed up at any suggestion that there is a strong environmental component in autism

      I realize that you would think such a thing. I just don’t understand why. I know you have skipped many posts I have written (as evidenced by your comments where you clearly hadn’t read the research discussed). But I don’t think mere ignorance of my position is at play here.

      One of the great ironies is that I am portrayed (not just by you, but by others who clearly don’t read/understand what I write) as being opposed to the idea that autism can have environmental causes. The irony comes in the fact that I accurately report the fact that environmental causation research has increased dramatically. Environmental causation and gene-environment interactions make up 60% of the IACC proposed budget as far back as 2009. The myth that the IACC doesn’t support environmental causation research. Those who supposedly support environmental causation often still perpetuate the myth that genetic research is the vast bulk of causation funding.

      You will notice that I don’t write, “Why are they funding environmental causation so much!!!”.

      I also reported on the Bearman twin study (the one you missed), which I considered to be one of the major papers of that year. From Social Demographic Change and Autism: part 2

      This study has the possibility to have a major impact on autism causation research. I would not be surprised at all if this ends up as one of the papers highlighted by the IACC for the year. I’m certain that this paper will be brought up in online discussions for some time to come, what with the very different estimate of twin concordance than previously quoted.

      These are just a few examples. You can also read my discussion of Patricia Rodier’s testimony to the Omnibus Autism Proceeding where she spelled out many likely environmental causes of autism.

      As to SFARI, it is one of my favorite blogs. I write about it fairly regularly here. Are these pieces supposed to be news to me?

      If you want to beat on the straw-man Sullivan, I can recommend some blogs where the authors have opinions like yours. They aren’t based in fact, but neither is your opinion.

    • Sullivan March 1, 2012 at 22:30 #

      RAJ,

      here’s another link I meant to include. My 2008 article on Patricia Rodier’s discussion of environmental causation.

      But I am fairly sure we have been around this discussion before. You seem to prefer your stereotype of me rather than the facts before you. You are welcome to do so, just don’t expect me to agree with you.

  9. Science Mom March 1, 2012 at 14:07 #

    @ Cindy, your first link looks like a student thesis, the second gives a 404 error. But more importantly, my German is so stale that it would take me a long time to slog through the thesis so you may want to provide an English text.

  10. Lawrence March 1, 2012 at 15:13 #

    But aren’t symptoms of heavy metal poisoning, particularly mercury, completely different than the way autism presents itself?

    • Sullivan March 1, 2012 at 22:28 #

      But aren’t symptoms of heavy metal poisoning, particularly mercury, completely different than the way autism presents itself?

      Absolutely. Patricia Rodier went into great detail on this account in her testimony for the Omnibus Autism Proceeding.

  11. Catherina March 1, 2012 at 18:11 #

    SM, the first text is a third semester psychology student’s home work and the pertinent chapter is not free online. I would not really consider this a “source”. The second is a link to a blog (it works if you remove the ) at the end of the link and it discusses very shortly this paper:

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2810427/?tool=pubmed

    which reads borderline relevant to me.

  12. David N. Andrews M. Ed., C. P. S. E. March 3, 2012 at 02:49 #

    Lawrence: “But aren’t symptoms of heavy metal poisoning, particularly mercury, completely different than the way autism presents itself?”

    Some years ago, I did a very detailed comparison somewhere on this very issue.

    Yes, they are very different indeed.

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