Thursday, August 27, 2009

Clinic Notes: Mercury and Autism

Many parents who bring their children with autism to my clinic tell me that their child was developing normally and they thought everything was fine, and then, sometime between the age of 2 and 3 their child began to loose words and regress. The only thing the parents can recall that was different was that the regression happened after the vaccinations that are normally given at that time the regression occurred. Mercury is a heavy metal that is toxic and many people think, that this must be the cause of autism. But if this is true why don't all children get autism? Ok maybe some children are able to metabolize the mercury and other children cannot. But then why did the rates of autism not fall when the mercury was taken out of the vaccine? Furthermore, why are the autism rates the same in vaccinated and non-vaccinated children in countries that do not require vaccinations?
Now at this point I am not ready to clear mercury as a potential cause of autism. A recent study involving more than 6000 women found blood mercury levels rising in American women. This is not surprising. Mercury is increasing in our environment. The number of coal plants that produce electricity are increasing, and a recent survey found that a quarter of the fish found in US streams and lakes have unsafe levels of mercury. (This at a time when health experts are touting fish as a brain food and telling us to increase our consumption of fish.) I also hear that mercury pollution from Chinese coal plants ends up in California soil and is re-released into the air during the fire season. Mercury levels in women accumulate as they age and could affect the fetus. Older mothers are more likely to have a child with autism.) At this point, more research on mercury in the environment and its relation to autism needs to be done.