Researchers reported that children with autism had higher levels of toxic metals in their blood and urine vs. healthy children. The levels of those toxic metals were associated with the severity of the disorder.
“These significant associations may offer clues to the etiology of autism,” the researchers wrote. “For example, there has been extensive speculation that toxic metals may contribute to the severity of autism, in part because of low glutathione which is needed to remove some toxic metals.”
The study included 55 children with autism aged 5 to 16 years and 44 neurotypical children of similar age and gender. Three valid measures were used to assess the severity and symptoms of autism. The researchers screened for toxic metals in participants’ whole blood, red blood cells and urine. They found that the children with autism had significantly higher levels of lead in their red blood cells (41%; P=.002) and significantly higher urinary levels of lead (74%; P=.02), thallium (77%; P=.0001), tin (115%; P=.01) and tungsten (44%; P=.00005).
However, children with autism had slightly lower levels of cadmium in whole-blood samples (–19%; P=.003).
Additional analyses indicated a strong association between the levels of toxic metals with the severity of autism (P<.0003).
The researchers said the reason for the higher burden of toxic metals among children with autism may stem from increased exposure to the toxic metals, increased absorptions as a result of intestinal permeability or decreased ability to excrete the toxic metals.
“We hypothesize that reducing early exposure to toxic metals may help prevent or ameliorate autism, and treatment to remove toxic metals may reduce symptoms of autism,” they wrote.
Disclosure: The researchers report no relevant financial disclosures.