Although the causes of autism have not been clearly identified, research has suggested that chronic biochemical imbalance plays a role.

Studies have shown that levels of the major intracellular antioxidant glutathione are typically about 50 percent lower in children with autism. Glutathione, which is produced by every cell in the body, is responsible for a number of functions including removing or neutralizing dangerous substances that people are exposed to on a daily basis, including toxic metals, according to scientists at the University of Southwestern Medical Center in Dallas.

"Some children with autism are poor detoxifiers relative to normally developing children, and in particular, have trouble excreting toxic metals," said Dr. Janet Kern, a professor of psychiatry.

"Toxic metals that are not eliminated may build up in the brain. Plasma glutathione has been found to be lower in children with autism, particularly, in children with autism who have regressed. We want to clearly establish that raising glutathione levels in these children will improve their ability to detoxify these substances and in that way improve some of their symptoms."