Saturday, July 24, 2010

Trace and Toxic Elements Related to Severity of Autism

Photo via Wikimedia Commons
Is there a relationship between certain trace and toxic elements and autism?

 I know this is one of those areas that gets everyone all riled up, but I ran across the a study earlier this month and thought the results were interesting and worth pointing out. Just a quick note before I start, if you are one of the people who see the M word used in an article about autism and get all bent out of shape, I would ask that you ignore that part of it and consider the other the other findings. So, without further ado..

The study in question looked for and found a possible relationship between the levels of trace and toxic elements and the severity of autism in children. The trace elements in question are copper, zinc, magnesium, and selenium while the toxic elements are lead and mercury.

The researchers looked at hair and nail samples from a total of 95 children. These children were divided into four groups - a typical (control) group with 50 children, and a low functioning group (LFA) with 15 children, a medium function group (MFA) with 15 children, and high function group (HFA) that also had 15 children. The children were placed in their groups by their score on the Childhood Autism Rating Scale (CARS) test, a older but still valid test for autism. Children in the HFA group had a score on the CARS of 15-30, MFA was 30-45, and LFA was 45-60.  The children lived in India and were between the ages of 4 and 12. The groups were matched on age as well as gender.

The researchers analyzed the samples and found that there were significant relationships between the severity of autism and the measured level of these elements. In general, children with more severe autism had higher levels of copper, lead, and mercury and lower levels of selenium and magnesium. Zinc was the exception as there wasn't a significant relationship between severity and the level measured. However, children in the LFA group did show a significant decrease in zinc when compared to the control group.

Since these relationships are easier to visualize rather than read, I am including some graphs below that show the mean values for each group for each sample type (hair and nail). Most of the values below reached the threshold for significance ( p < 0.01 or p < 0.001) but not all of them did (Zinc in hair and nails for MFA and LFA as well as lead in nails for MFA and HFA did not).

There are two caveats to keep in mind as you look at the charts.

First, these data points do not "prove" that autism is caused by any specific thing. They only show a relationship between the level measured and a severity of autism. Or to put it a different way, the relationship here is between the level measured in hair or nails and the score on the CARS test.  Although on the flip side, CARS is a decent test and can distinguish between autism and pdd-nos, so it should be an acceptable way of determining severity.

Second, there is no data about why the numbers look the way they do. All of the children were from the same general area but that does not mean that they all come from the social or economic background. It is also entirely possibly that these differences could be caused by differences in diet between the groups

However, it is my feeling that these results do reflect the reality of what can happen in certain children with autism. As a case in point, all of my own children show an elevated (almost toxic) level of copper, a low level of zinc (2 of 3 were zinc deficient), and low levels of selenium.


Lakshmi Priya, M. D., & Geetha, A. (2010). Level of Trace Elements (Copper, Zinc, Magnesium and Selenium) and Toxic Elements (Lead and Mercury) in the Hair and Nail of Children with Autism. Biological trace element research. doi: 10.1007/s12011-010-8766-2.


  1. Hi MJ -

    Very nice post. The copper / zinc ratio you describe is extremely common in our children, and very difficult to 'fix'. It was reported officially here:

    Though I had the same profile observed in my son years previously.

    My thoughts are that it likley that something about having autism, perhaps oxidative stress, is causing the children to hold onto specific metals, as opposed to the other way around. That being said, I also believe that restoring those balances, to the extent that it is possible, is likely benificial to many.

    - pD

  2. Well I don't know. It's not my prime interest but I doubt this would overthrow my(i) particular thery of emergent properties and chaos mathematics, in fact it might even re-inforce it so there you go.

    (i) that is a rather disengenous claim on my part I did not originate the idea.

  3. Hi pD,

    Thanks, I am glad you liked the post. It is nice to know that somebody other than me finds this stuff interesting.

    My kids, especially the twins, had zinc/copper ratios way out of whack. Before we started doing anything, their zinc/copper was about 0.25 - which was about half of the mean cited by the study that you mentioned (which was itself very low). We have managed to increase their zinc level and lower their copper level and now they are at about 0.6 today. Still low, but much better than they were.

    I don't know if it was hard to get them to this point, it just took giving them a good amount of extra zinc every day for the past several years...

    As to which comes first, the deficiencies or the autism, I don't really know. There are so many things out of whack biologically in children like mine (and presumably yours) that it is hard to separate out cause and effect. Did the autism cause them all or was the autism caused by so many things being out of sorts, or is a combination of both?

    Hopefully one day we will get a good answer to that question, but until then I agree that correcting these imbalanaces as best we can is a good idea.

  4. Author, I am not quite sure what you are trying to say, perhaps you could explain?

  5. I've tried explaining it to SBC too and I am not sure he understands either :(

  6. I understand what the words mean and I have a somewhat decent grasp of the basics of chaos theory, but I am not sure how they would apply to trace elements and autism?

    Are you trying to say that you think that autism is somehow altering the underlying biological systems so these results are not abnormal for someone who has autism?

  7. What I said has nothing to do with trace elements as such, it is just that I do not dismiss the interaction of environmental factors with genetics out of hand as being catalytic in chaotic events in brain development.

  8. Hi MJ
    Very interesting to me, too :)
    Now, we are 3! :(
    My son also show abnormal results in aminoacids in urine/ blood.
    Unfortunately, there has not been a profound analysisis of the published literature in such a way a group expert in metabolism/toxicology made a coherent hypothesis. With the abnormal management of proteins/aminoacids metabolism many subgroups of autistic children have- related to the glutathion circuit and metabolism of xenobiotics- AND the abnormal management of toxic and essential elements,some important areas remain unstudied. For example
    What is the role of aminoacids/proteins abnormal management in the proposed bioaccumulation of toxic elements and loss of essential ones, in different subgroups of children with autism?
    what is the impact of a GFCFSF diet on the parameters of aminoacids and metals during time on diet- especially if other fungal and bacterial problems are treated together- without Se and aminoacids supplementation?
    Se and certain aminoacdis are key in the metabolism of glutathion...
    The work of Dr James is very interesting but the need of further research on the topic is so high
    Dr Zalups group is very active in for example mercury and there are very recent published literature on lead

  9. Environ Res. 2010 Jul;110(5):476-83.

    Environmental exposure to lead, but not other neurotoxic metals, relates to core elements of ADHD in Romanian children: performance and questionnaire data.
    Nicolescu R, Petcu C, Cordeanu A, Fabritius K, Schlumpf M, Krebs R, Krämer U, Winneke G.

    Institutul de Sanatate Publica, Str. Dr. Leonte 1-3, 050463 Bucuresti, Romania.

    Neurobehavioral measures of attention, and clinical features of the attention-deficit hyperactivity disorder (ADHD) have been studied in pediatric environmental lead research. However rarely, if ever, have performance measures of attention or executive functions and questionnaire-based quantitative ADHD-observations been studied in the same subjects. We examined associations between pediatric blood lead concentrations (PbB), as well as those of mercury (Hg), and aluminum (Al), and performance in four different attention tasks, as well as behavioral ratings from an ICD-10 (hyperactivity) and DSM-IV-coded (attention deficit) German questionnaire (FBB-ADHS). Asymptomatic, 8-12 year old children from two Romanian cities were studied, namely Bucharest and Pantelimon, a city near a metal-processing plant. Blood was analyzed for Pb, Al, and Hg. Data from 83 children were available for final analysis. We assessed attention performance by means of four tasks of the computer-based ADHD-taylored German KITAP-battery. We also received questionnaire ratings from parents and teachers covering three ADHD-dimensions. Multiple linear regression analysis was used to estimate associations between the three neurotoxic trace metals in blood and the different ADHD features. After adjusting for eleven potentially confounding variables we found consistent borderline to significant associations between Pb, but not other metals, in blood and various performance- and questionnaire data. False alarm responses (FAR) in the KITAP subtests rather than response latencies exhibited positive associations with PbB. Questionnaire ratings for ADHD dimensions also revealed PbB-related adversity. With any two-fold increase of PbB outcome changed markedly, namely up to 35%. Restriction to children with PbBs<10mug/dl had only a marginal influence on outcome.The converging evidence from performance- and questionnaire data confirms that core elements of ADHD are adversely affected by low environmental PbB even below 10mug/dl, but not by other neurotoxic trace metals. Observed effect-sizes are considerably larger than those typically found for lead-related IQ-deficit, thus suggesting that attention deficit could be the more basic adverse effect of lead in children. This is the first study from Central and Eastern Europe dealing with links between environmental exposure of children to neurotoxic metals and ADHD.
    J Toxicol Environ Health B Crit Rev. 2010;13(5):385-410.

    Transport of inorganic mercury and methylmercury in target tissues and organs.
    Bridges CC, Zalups RK.
    Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, Georgia 31207, USA.
    Owing to the prevalence of mercury in the environment, the risk of human exposure to this toxic metal continues to increase. Following exposure to mercury, this metal accumulates in numerous organs, including brain, intestine, kidneys, liver, and placenta. Although a number of mechanisms for the transport of mercuric ions into target organs were proposed in recent years, these mechanisms have not been characterized completely. This review summarizes the current literature related to the transport of inorganic and organic forms of mercury in various tissues and organs. This review identifies known mechanisms of mercury transport and provides information on additional mechanisms that may potentially play a role in the transport of mercuric ions into target cells.

  10. sorry MJ, please erase the additional posts thanks

  11. Thanks Maria, I haven't seen either of those before, I will have to add them to my reading list.

    I think I got all of the duplicate comments, feel free to repost if I deleted the wrong ones. Blogger seems to be having some sporadic commenting issues.