NEW YORK (Reuters Health) - Removing heavy metals from the body through a process traditionally used to treat mercury and lead poisoning doesn't help relieve autism symptoms, a new analysis suggests.
During chelation therapy, patients are given injections of a chemical that binds to heavy metals, lowering their concentration in the blood and ultimately allowing the metals to be excreted through urine.
Chelation gained traction as an alternative treatment for autism due to a theory that mercury poisoning might play a role in the developmental disorder. However, evidence hasn't supported that idea and it's been essentially discarded in the scientific community, researchers said.
The procedure also carries safety concerns, including risks of kidney damage and gastrointestinal problems.
Lead researcher Tonya Davis from Baylor University in Waco, Texas, said the study team's goal was not to tell parents which treatments they should or shouldn't seek for their children.
"I see that they want to try everything, and they are well intentioned," she told Reuters Health.
"But there are risks involved with any treatment choice, and some of those risks are very serious. So far science does not support (chelation) as being an effective treatment, and that's a big risk to take when you have limited resources and limited time."
The Centers for Disease Control and Prevention estimates that one in 88 kids in the U.S. has an autism spectrum disorder.
Davis and her colleagues found five studies that tested the effects of chelation in kids with autism. Those studies each had between one and 41 children, from age three to 14.
Researchers had given the kids chelation therapy - sometimes along with vitamin supplements or other treatments - between one and 12 times a week for up to seven months. They used tests and questionnaires or anecdotal reports from parents to see how symptoms changed over time.