Mercury Levels Same in Normal and Autistic Children
In a rigorous study, no significant difference in mercury levels in the bloodstream has been found comparing normal and autistic children. The findings come from UC Davis MIND Institute scientists looked at mercury levels in the bloodstream of children who have autism and children who do not, finding that levels are the same.
The researchers are cautious in saying the study does not examine whether mercury plays a role in the development of autism. "The bottom line is that blood-mercury levels in both populations were essentially the same. However, this analysis did not address a causal role, because we measured mercury after the diagnosis was made”, said lead study author Irva Hertz-Picciotto, an internationally known MIND Institute researcher and professor of environmental and occupational health.
The findings that mercury levels are similar in normal and autistic children come from the Northern California-based Childhood Autism Risks from Genetics and the Environment (CHARGE) Study, led by Hertz-Picciotto. The study included clues to its origins children between 24 and 60 months diagnosed with autism, children with developmental disorders normally developing children.
The researchers found when looking for all sources of mercury in the bloodstream of children, including vaccines, personal care products, dental fillings, and fish consumption, that fish was by far the biggest source of mercury in the body. Though a few children had recently been vaccinated, their mercury levels were not elevated.
The study included 452 children – of those 249 had autism, 60 had delays in development, and 143 were developing typically. At first, lower levels of mercury were found in the children with autism, but after adjusting for diet, mercury levels were the same in normal and autistic children.
A study published January 2009, showed no link between vaccines and autism, a concern of parents pondering the benefits versus risks of immunizing their children against childhood diseases.
The authors say that autism is so complex, a multi-faceted approach to discovering the cause is needed. According to Hertz-Picciotto, “It's time to abandon the idea that a single 'smoking gun' will emerge to explain why so many children are developing autism." The findings that mercury levels were found to be similar in normal and autistic children should mandate more research.