Unequivocally, There is Strong Evidence Linking Thimerosal to Autism
Open Letter to Gov. Linda Lingle
By Richard C. Deth, PhD, 7/3/2006 11:45:51 AM

I am a neuropharmacologist and Full Professor at Northeastern University in Boston who has been investigating the molecular origins of neurodevelopmental and neuropsychiatric disorders. For the past few years much of my lab's work has focused on autism, including an evaluation of the possible contribution of thimerosal, the ethylmercury-containing vaccine preservative. Based upon my expertise in this area I have testified to Congress on several occasions, appeared on NBC Nightly News and in several documentaries and presented our findings at numerous scientific conferences.

I understand that you are currently evaluating legislation to removal thimerosal from vaccines used in Hawaii. Let me state unequivocally that there is strong scientific evidence linking thimerosal to autism, so taking steps to remove it from vaccines is a true "no-brainer". Moreover, it is vital that states indicate their expectation of thimerosal-free vaccines in order to shift the pharmaceutical industry to this safer form. Public confidence in the vaccination program will be greatly increased when mercury is removed, allowing the full public health benefits without the unnecessary mercury burden.

Our research has shown that very low concentrations of thimerosal, typical of those found in the blood following vaccination, cause strong inhibition of metabolic processes that are crucial to neuronal cell well-being and survival. The most sensitive of these processes involves sulfur metabolism, including the anti-oxidant defense mechanism that is critical to all cells. The effect of thimerosal is to significantly lower levels of glutathione, the primary cellular antioxidant. Studies of autistic children clearly show that they are suffering from oxidative stress and their glutathione levels are reduced by 40-50%. Thus the toxic metabolic actions of thimerosal are paralleled in clinical studies of autistic children.

In further studies we showed that thimerosal inhibits a key cellular process called "methylation", in which various activities, including gene expression, are controlled by the transfer of a single carbon atom. Methylation is closely linked to oxidative stress, and when thimerosal induces oxidative stress, it also causes impaired methylation. Again, blood tests in autistic children show that they have impaired methylation. Furthermore, metabolic therapies that help restore methylation have been able to improve the clinical symptoms of many autistic children, strongly indicating that this metabolic dysfunction plays a central role. Genetic studies have also revealed a higher frequency of risk-inducing polymorphisms and mutations affecting methylation and sulfur metabolism. Our most recent research indicates that the brain has a particularly higher vulnerability to oxidative stress, which helps explain why neurological problems occur with low doses of thimerosal.

The point of all this scientific background is to reinforce the common sense logic of reducing mercury exposure by all possible routes, including vaccine-related. It is illogical to inject mercury into anyone, at any age, and you will be doing a service to all Hawaiians by helping to restrict their exposure by signing SB2133 part II.

If I can help provide any further background, please feel to contact me. I am eager to assist.

Richard C. Deth, PhD is a Professor of Pharmacology for Northeastern University in Boston, Massachusetts