The Role of Zinc and Copper in Autism Spectrum Disorders

Acta Neurobiol Exp 2013 2Children with Autism spectrum disorders (ASDs) appear to be at risk for zinc (Zn) deficiency, copper (Cu) toxicity, have often low Zn/Cu ratio, and often disturbed metallothionein (MT) system functioning. The evidence presented in this paper suggests that providing Zn to autistic children may be an important component of a treatment protocol, especially in children with Zn deficiency. It is important to monitor and follow the values for both Cu and Zn together during Zn therapy, because these two trace elements are both antagonists in function, and essential for living cells. 

The review article by Geir Bjørklund is published in Acta Neurobiologiae Experimentalis (2013; 73 (2): 225–236). This peer-reviewed journal is published by Nencki Institute of Experimental Biology in Warsaw, Poland.

 

Geir Bjørklund

The role of zinc and copper in autism spectrum disorders

Acta Neurobiol Exp (Wars) 2013; 73 (2): 225-236 

 

ABSTRACT

Autism spectrum disorders (ASDs) are a group of developmental disabilities that can cause significant social, communication and behavioral challenges. Several studies have suggested a disturbance in the copper (Cu) and zinc (Zn) metabolism in ASDs. Zinc deficiency, excess Cu levels, and low Zn/Cu ratio are common in children diagnosed with an ASD. The literature also suggests that mercury accumulation may occur as a cause or consequence of metallothionein (MT) dysfunction in children diagnosed with an ASD, which may be one of the causes of Zn deficiency. MTs are proteins with important functions in metal metabolism and protection. Zinc and Cu bind to and participate in the control of the synthesis of MT proteins. Studies indicate that the GABAergic system may be involved in ASDs, and that Zn and Cu may play a role in this system.

 

Mercury Dental Fillings Infographic

mercury dental filling

Discover more about mercury and how you can get this toxic, bioaccumulative substance from your dentist through our infographic “Mercury Dental Fillings: By the Numbers.” Use the embed code to share it on your website.

<img src="http://media.mercola.com/assets/images/infographic/dental-fillings.jpg" alt="mercury dental filling" border="0" style="max-width:100%; min-width:300px; margin: 0 auto 20px auto; display:block;">

Discover more about mercury and how you can get this toxic, bioaccumulative substance from your dentist through our infographic “Mercury Dental Fillings: By the Numbers.” Use the embed code to share it on your website.

Counting the cost of mercury pollution

MercuryCleaning up mercury pollution and reducing prenatal exposure to the neurotoxin methylmercury (MeHg) could save the European Union EUR 10,000 million per year, finds a new study published in BioMed Central’s open access journal Environmental Health. New estimates suggest that between 1.5 and 2 million children in the EU are born each year with MeHg exposures above the safe limit of 0.58µg/g and 200,000 above the WHO recommended maximum of 2.5µg/g.

While some mercury occurs naturally in the environment for example from volcanic eruptions or forest fires, most is generated by burning fossil fuels. Marine and fresh water species bioconcentrate MeHg; consequently the main source of exposure for humans is from eating fish.

A team of researchers from across Europe used the DEMOCOPHES study of exposure to environmental chemicals to assess the impact of MeHg on humans. Hair samples of child-mother pairs, collected from 17 European countries, demonstrated that, as a lower estimate, 1,866,000 children are born in Europe exposed to toxic levels of MeHg. 232,000 of these are exposed to hazardous levels, five times higher. But not every child in Europe is equally at risk. When analysed per country, children born in Portugal and Spain were the most exposed to MeHg, and Hungary the least.

Exposure to MeHg in humans affects brain development, resulting in a lower IQ, and consequently a lower earning potential. The long term cost to society can be calculated as lifetime earning loss per person, although this estimate does not take into account other aspects of brain toxicity or risks of cardiovascular disease in adults.

Prof Philippe Grandjean explained, “If we convert the effects of MeHg on developing brains into IQ points then the benefits of controlling MeHg pollution equates to 700,000 IQ points per year and monetary benefits of EUR 8,000 to EUR 9,000 million per year for the whole of the EU. Exposure abatement would mainly benefit southern Europe .”

Once MeHg is formed, it cycles though the environment for thousands of years, exposing humans and other species to potentially toxic levels for generations. Commenting on the research Dr Elsie Sunderland said, “Mitigating the harm caused by methylmercury requires global-scale cooperation on policies and source reductions. Negotiations by the United Nations Environment Program are currently underway to address mercury emission levels.”

 

References

Bellanger M, Pichery C, Aerts D, Berglund M, Castano A, Cejchanová M, Crettaz P, Davidson F, Esteban M, Exley K, Fischer ME, Gurzau AE, Halzlova K, Katsonouri A, Knudsen LE, Kolossa-Gehring M, Koppen G, Ligocka D, Miklavcic A, Reis MF, Rudnai P, Tratnik JS, Weihe P, Budtz-Jørgensen E, Grandjean P. Economic benefits of methylmercury exposure control in Europe: Monetary value of neurotoxicity prevention. Environmental Health 2013, 12:3 doi:10.1186/1476-069X-12-3.

Mercury Rising

The Arctic is one of the regions of the world to which mercury is transported and accumulates in the food chain. The substance continues to be a threat to people and wildlife in the Arctic. A special issue is related to the increasing content of mercury in Arctic species such as polar bears, toothed whales and birds despite a reduction in anthropogenic emissions from Europe and North America.

 

The World’s First Global Mercury Ban

More than 140 nations adopt treaty to cut mercury – www’s column on NewsvineGENEVA – A new and legally binding international treaty to reduce harmful emissions of mercury was adopted Saturday by more than 140 nations, capping four years of difficult negotiations but stopping short of some of the tougher measures that proponents had envisioned.

Embedly Powered

After a week of intense negotiations, the world’s first global mercury ban is clear. While no dental amalgam phase out date has been set,  during the negotiations that led to the new treaty on mercury, article 6 on products in Annex C  Part  II, requires countries to take steps to phase down dental mercury globally. “This is the beginning of the end of dental amalgam globally,” said Michael T. Bender, MPP director. “We applaud the leadership role the US played in jump-starting support for a phase down in 2011 along with the concrete steps in Nordic countries, Switzerland and Japan in phasing out amalgam.”

 

Read More

UN treaty on mercury expected to phase down amalgam globally

Summary of The Fifth Session of The Iintergovernmental Negotiating Committee to Prepare A Global Legally Binding Iinstrument on Mercury: 13-19 January 2013. Earth Negotiations Bulletin 2013; 28, No. 22: 1-25.

 

UN treaty on mercury expected to phase down amalgam globally

Draws praise from consumer, dental and environmental groups:

Dental AmalgamsWhile no dental amalgam phase out date has been set, UN mercury treaty talks are expected to result in the phase down of dental mercury globally, says representatives of consumer and environmental groups attending the negotiations.  Amalgam phase down text incorporated in Annex C of Article 6 on products is expected to shortly be transmitted to the Intergovernmental Negotiation Committee plenary for its approval. [1]

“This is the beginning of the end of dental amalgam globally,” said Michael T. Bender, director of the Mercury Policy Project, a US-based NGO, who is attending the mercury treaty talks. “We applaud the leadership role the US played in jump-starting support for a phase down in 2011 along with the concrete steps of the Nordic countries, Switzerland and Japan in phasing out amalgam.”

“Countries that have phased out amalgam recognize that mercury-free dental fillings are readily available, affordable and effective,” said Charles G. Brown, Esq., World Alliance for Mercury-Free Dentistry, a global coalition of NGOs, dentists and consumers from over 25 countries. “This pushes the reset button on dentistry. Now the rest of the world can benefit from the experience of those countries.”

The draft treat text outlines a variety measures countries can take to phase down amalgam, but shall include at least two of the several listed. These include setting national objectives minimizing dental amalgam use; promoting mercury-free alternatives for dental restoration; and discouraging insurance policies and programs that favor dental amalgam over mercuryfree alternative dental restorations.

Other measures are targeted at reducing global dental mercury pollution and involve restricting amalgam use to its encapsulated form and promoting best environmental practices in dental facilities. It also encourages dental schools to train dentists on using mercury-free alternatives and best management practice.

Many countries have already been considering similar measures, due to the significant use and release of dental mercury pollution globally. A 2012 report for the European Commission (EC) recommended phasing out amalgam in five years. [2]

The EC BIOS report also noted that mercury-free fillings appear more expensive than amalgam because of the negative external costs. Amalgam’s negative environmental effects are known and ultimately, society pays for the uncontrolled release of dental mercury, as explained in our 2012 report. [3]

According to the United Nations Environment Programme (UNEP), the use of mercury in tooth fillings represents some 10% of global mercury consumption, thus being among the largest consumer uses of mercury in the world. UNEP estimates global use of dental mercury at between 300 – 400 metric tonnes per year. [4]

 

Endnotes:
[1] The Negotiating Process
[2] European Commission report by BIOS
[3] Real Cost of Dental Mercury Pollution, by Concorde
[4] MAP/UNEP 2008.  Source: Mercury Policy Project

 

Dental Mercury’s Toxic Journey Into The Environment

Dental Toxic“Dental Mercury’s Toxic Journey Into The Environment” was narrated by Robert Lamarck and produced as a collaborative effort between The International Academy of Oral Medicine and Toxicology, the website Mercury Exposure and the film You Put What In My Mouth? a documentary about the devastating effects of dental mercury on patients, staff and the environment.

The IAOMT has sent a distinguished panel of experts to attend the International Negotiating Committee (INC5) meeting being held in Geneva by the United Nations Environmental Programme. The INC5 is writing a Globally Binding Treaty that will eliminate the use and trade of mercury and mercury containing products. Dental Mercury accounts for 10% of the annual global emissions and therefore is considered a significant contributor. The IAOMT group of experts will represent our position that mercury amalgam is a risk to the environment, dental workers and the general public, and whose use should be discontinued as there are many suitable alternatives available.

Chemical Brain Drain (Lecture)

Brain development can be damaged by mercury and other environmental chemicals.

This is a lecture by Professor Philippe Grandjean who works at the University of Southern Denmark and Harvard School of Public Health in the United States. He tells in the presentation that there are 201 environmental chemicals currently identified as harmful for the brain. These toxic substances can cause the so-called brain drain, which means that the population’s skills decrease with more mental health problems and fewer highly intelligent people.

Grandjean also shows the magnetic resonance scanning of the brain when children make different finger movements. In children with high mercury levels are both right and left brain active instead of just one in children with low mercury load. This shows that the nerve impulses in mercury affected brains are not functioning optimally.

Mad Child Disease (Lecture)

Is the autism epidemic a “mad child disease” linked to mercury? This lecture was presented by Boyd Haley, Ph.D. at the 22nd Annual Meeting of the Doctors for Disaster Preparedness held in San Diego, California; June 2004.

Prenatal Mercury Exposure May be Associated with Risk of ADHD-related Behaviors

Fish consumption may be associated with lower risk

GravidCHICAGO – A study of children in the New Bedford, Mass., area suggests that low-level prenatal mercury exposure may be associated with a greater risk of attention-deficit/hyperactivity disorder (ADHD)-related behaviors and that fish consumption during pregnancy may be associated with a lower risk of these behaviors, according to a report published Online First by Archives of Pediatrics & Adolescent Medicine, a JAMA Network publication.

ADHD is one of the most common neurodevelopmental disorders of childhood and affects 8 percent to 12 percent of children worldwide, although its cause is not well understood. The developmental neurotoxicity of mercury is known, but the findings from epidemiological studies are inconsistent with some studies showing associations between mercury exposure and ADHD-related behaviors and others reporting null associations, according to the study background.

Nonoccupational methylmercury exposure comes primarily from eating fish, and the U.S. Environmental Protection Agency and the U.S. Food and Drug Administration have recommended pregnant women limit their total fish intake to no more than two, six-ounce servings per week. However, fish is also a source of nutrients, such as omega-3 fatty acids, which have been shown to benefit brain development, potentially confounding mercury-related risk estimates, the study background also indicates.

Sharon K. Sagiv

Sharon K. Sagiv, Ph.D., M.P.H., of the Boston University School of Public Health, and colleagues analyzed data from the New Bedford birth cohort, a group of infants born between 1993 and 1998, to investigate the association of peripartum maternal hair mercury levels (n=421) and prenatal fish intake (n=515) with ADHD-related behaviors at age 8 years.

“In this population-based prospective cohort study, hair mercury levels were consistently associated with ADHD-related behaviors, including inattention and hyperactivity/impulsivity. We also found that higher prenatal fish consumption was protective for these behaviors,” the authors comment.

Statistical analysis indicates mercury exposure appeared to be associated with inattention and impulsivity/hyperactivity and some outcomes had an apparent threshold with associations at 1 μg/g (microgram/per gram) or greater of mercury. For example, at 1 μg/g or greater, the adjusted risk ratios for mild/markedly atypical inattentive and impulsive/hyperactive behaviors were 1.4 and 1.7 respectively, according to the study results.

There also appeared to be a “protective” (lower risk) association for fish consumption of greater than two servings per week with ADHD-related behaviors, particularly impulsive/hyperactive behaviors (relative risk = 0.4), the study results show.

“In summary, these results suggest that prenatal mercury exposure is associated with a higher risk of ADHD-related behaviors, and fish consumption during pregnancy is associated with a lower risk of these behaviors,” the authors conclude. “Although a single estimate combining these beneficial vs. detrimental effects vis-à-vis fish intake is not possible with these data, these findings are consistent with a growing literature showing risk of mercury exposure and benefits of maternal consumption of fish on fetal brain development and are important for informing dietary recommendations for pregnant women.”

 

Attention-Deficit/Hyperactivity Disorder a Preventable Epidemic?

Bruce P. Lanphear

In an editorial, Bruce P. Lanphear, M.D., M.P.H., of Simon Fraser University, Vancouver, British Columbia, Canada, writes: “The study by Sagiv et al, which tested whether prenatal exposure to methyl mercury was associated with the development of ADHD-related behaviors, is an important and rigorously conducted prospective birth cohort study.”

“What are the implications of the Sagiv et al study and other research on environmental contaminants and ADHD? First, we can take some comfort in recent legislation to reduce mercury contamination, at least from domestic sources. Second, these studies should spur our efforts to enhance the collection of data needed to calculate national estimates and trends in ADHD,” Lanphear continues.

“Third, it is time to convene a national scientific advisory panel to evaluate environmental influences of ADHD and make recommendations about what can be done to prevent it. Fourth, this study and a flurry of new evidence linking environmental contaminants with ADHD reinforce the urgency of revising the regulatory framework for environmental contaminants and toxicants,” Lanphear concludes.

 

References

Sagiv SK, Thurston SW, Bellinger DV, Amarasiriwardena C, Korrick SA. Prenatal Exposure to Mercury and Fish Consumption During Pregnancy and Attention-Deficit/Hyperactivity Disorder–Related Behavior in Children. Arch Pediatr Adolesc Med. 2012;():1-9. doi:10.1001/archpediatrics.2012.1286.

Lanphear BP. Attention-Deficit/Hyperactivity Disorder A Preventable Epidemic? Arch Pediatr Adolesc Med. 2012;():1-3. doi:10.1001/archpediatrics.2012.1900.