Source : www.naturalnews.com
by David Gutierrez, staff writer
(NaturalNews) New evidence suggests that heavy metal exposure may be a cause of autism, in a study conducted by researchers from Arizona State University and published in the journal Biological Trace Element Research.
The researchers found that autistic children had significantly higher levels of numerous toxic metals in their blood than non-autistic children.
Autism is a neurological disorder that causes repetitive or restricted behavior and trouble with communication and social interaction. According to theCenters for Disease Control and Prevention (CDC), it affects one in every 252 girls and one in every 54 boys in the United States. Although mainstream medicine long considered autism to be a hereditary disorder, increasing evidence is emerging that link the condition to various environmental factors, such as toxic exposure.
“Studies such as this improve our understanding,” said Caroline Hattersley of the UK-based National Autism Society. Further studies should be performed to back up this research, she said.
The researchers tested blood and urinary levels of various toxic heavy metals in 99 children between the ages of five and 15. 55 of the children had autism, while 44 did not. The groups were similar in age and gender distributions.
The researchers found that autistic children had 41 percent higher levels of lead in their blood and 74 percent higher levels in their urine than non-autistic children. Their urinary levels of tungsten were 44 percent higher, thallium levels were 77 percent higher and tin levels were 115 percent higher.
All four of these metals have previously been linked with impaired brain function and development, the researchers noted, and can be toxic to other organ systems as well.
Based on three separate scales of autism severity, the researchers also found that higher blood levels of toxic metals were associated with more severe cases of autism. In fact, between 38 and 47 percent of all variation in autism severity could be explained by varying heavy metal levels, particularly cadmium and mercury. This made toxic metal burden the single “strongest factor” predicting severity, the researchers said.
On one level, the findings come as no surprise, given the well-established neurotoxic effects of heavy metal exposure.
“We knew that exposure to lead makes people lose IQ points, and clearly it can induce autism,” lead researcher James Adams said. “The study also showed that people with the highest levels are least able to excrete them.”
The findings may have real-world implications for both preventing and treating autism, however.
“We hypothesize that reducing early exposure to toxic metals may help ameliorate symptoms of autism, and treatment to remove toxic metals may reduce symptoms of autism,” the researchers wrote. “These hypotheses need further exploration, as there is a growing body of research to support it.”
Adams has previously conducted research into the effectiveness of DMSA, a drug designed to remove toxic metals from the body. The study concluded that DMSA did indeed remove some metals successfully, and also reduced some symptoms of autism. Autistic children with the highest urine levels of metals benefited from the treatment the most.
DMSA Challenge Test for Heavy Metal Poisoning*
* Warning: The DMSA test must be administered under the supervision of a physician
and requires a physician prescription for DMSA (Chemet). Severe serious side-effects
may occur with DMSA usage.
Dimercaptosuccinic acid (DMSA) is a drug (CHEMET) approved for use in the treatment of
lead poisoning. It is a chelating agent that binds to heavy metals such as lead and mercury,
which are then eliminated in the urine as the DMSA is excreted. A significant benefit is that it
does not remove substantial amounts of other beneficial metals such as iron, calcium,
magnesium and zinc. In addition to the therapeutic use of DMSA, a brief administration of
DMSA followed by measurement of heavy metals in the urine is used as an indicator of the
body burden of heavy metals. The greater the body burden of toxic metals, the greater the
amount excreted after DMSA.
The approach to this test is that any increase in heavy metals after DMSA challenge is
considered significant. The patient is then treated with DMSA treatment until the toxic metals
in the urine are within the normal range after a DMSA challenge. An additional complication
for children is that even a six-hour urine collection may be difficult. Therefore, a single urine
sample collection after DMSA may sometimes be used.
DMSA Dosing Chart for challenge test:
Body Weight (lbs) Dose (mg) No. Capsules
18-35 100 1
36-55 200 2
56-75 300 3
76-100 400 4
>100 500 5
1. Immediately after awaking, empty the bladder completely. Do not eat any food for one
hour except for small amount of food needed to take the DMSA.
2. Obtain DMSA capsules in the proper dosage from the chart above by filling a prescription from
your doctor. Take the DMSA capsule with an 8-ounce glass of water or other fluid immediately
after the bladder is emptied. The capsules may be opened up and added to the food for children
or adults who have difficulty in swallowing capsules.
3. Collect all urine in the plastic collection jug for six hours after taking the DMSA capsule.
• You may eat breakfast one hour or more after taking the DMSA capsule.
• Drink only a moderate amount of fluid during the 6-hour collection period.
4. At the end of the 6-hours, empty the bladder of all urine into the collection jug one last time.
5. If you know from experience that you cannot collect the urine for six hours or you try to collect
six hours of urine but are unsuccessful, mark the requisition with the number hours you were
able to collect.
6. Follow the regular instructions for shipping urine samples.
Side effects of DMSA
The Physicians Desk Reference lists a number of side effects associated with DMSA usage. The side
effects affect between 1-20% of the individuals affected. It might be expected that a single dose of
DMSA would cause fewer side effects than a long-term treatment with DMSA.Side effects of DMSA (continued)
Gastrointestinal side effects include nausea, vomiting, stomach pain, and abdominal pain and diarrhea.
Hematological (blood) side effects include neutropenia, eosinophilia, and increased platelets.
Other side effects include elevated liver enzymes, drowsiness, dizziness, sleepiness, rash, decreased
urination, cardiac arrhythmia, leg and knee pain, and flu-like symptoms.
Treatment if challenge test is abnormal
If the challenge test is abnormal, then a treatment plan needs to be implemented. The most important
aspect of the treatment plan is the removal of any current source of heavy metal poisoning. If the child’s
house is contaminated with lead-based paint, the parents may have to move or have the lead removed
from the house. If the child is chewing on pajamas containing antimony-containing flame-retardant, they
may have to be replaced. If the child has significant mercury from vaccines containing the mercury
compound thimerosal, non-mercury vaccines should be used in the future. Excessive fish intake may
also cause mercury toxicity.
The next step is the use of agents to remove toxic metals. The most commonly used agent is DMSA.
Despite some side-effects DMSA is considered the safest prescription agent. It is fairly expensive with
a treatment cost that may range from $12 -$25 per day with an average treatment course of 19 days
and may need to be repeated if a significant heavy metal burden remains after treatment.
Certain nutritional supplements may also be used to remove heavy metals. In addition,
supplementation with beneficial metals such as calcium, magnesium, and zinc may also be helpful
since these metals may compete with toxic metals and reduce heavy metal toxicity.
The vitamin lipoic acid has two sulfhydryl groups that readily bind to mercury and result in its
elimination. This vitamin has no toxicity at doses used as a vitamin supplement and is sometimes used
as an adjunct to DMSA therapy. Lipoic acid is available in any health food store.
Peptidyl clathrating agent (PCA) is a dietary supplement and not a drug. According to John Wilson,
M.D. who has extensive experience in the removal of heavy metals, PCA is an extract of marine algae
and barley grass, cell wall components of olive leaf, colloidal silica, minerals, and components from
certain bacteria. Lipoic acid is high in this product and it is possible that the major active agent in this
product is its lipoic acid. A number of different mechanisms of action are claimed for this product.
Animal studies as well as clinical experience with humans seem to indicate that this agent is more
effective and less toxic than pharmaceutical chelating agents such as DMSA and DMPS. Furthermore,
PCA like DMSA does not remove beneficial elements. PCA is available from Timothy Ray OMD in Los
Angeles at 310 473-1813.
1. Aposhian V. DMSA and DMPS – Water-soluble antidotes for heavy metal poisoning. Ann Rev Pharmacol
Toxicol 1983; 23: 193-215.
2. Miller A. Dimercaptosuccinic acid (DMSA), a non-toxic, water-soluble treatment for heavy metal toxicity.
Altern Med Rev 1998; 3:199-207.
3. Graziano JH, et al. Controlled study of meso-2, 3-dimercaptosuccinic acid for the management of childhood
lead intoxication. J Pediatr 1992; 120:133-9.
4. Graziano JH, et al. Dose-response study of oral 2,3-dimercaptosuccinic acid in children with elevated blood
lead concentrations. J Pediatr 1988; 113:751-7.
5. Graziano JH, et al. Role of 2,3-dimercaptosuccinic acid in the treatment of heavy metal poisoning. Med
Toxicol 1986; 1:155-62.
6. John Wilson M.D. Update on Mercury Mobilization, The Great Lakes College of Clinical Medicine
International Conference, February 25-27,2000, Atlanta, GA.