NJ Think Tank "The Center for Modeling Optimal Outcomes, LLC", a primarily business-oriented group of smart guys, claims to have stumbled upon a link between a glycine-based stabilizer used in the US version of the MMR vaccine and autism spectrum disorders. Their shortened press release is so carefully worded it's like a goddamn journalistic minefield; they never actually commit to a link, and are careful to insist that this is explained in lay terms and is actually very very complicated (try me - I bet I'd understand!). The longer .pdf linked on their site explains more clearly that the proposed link is only there because someone's pulling a lot of correlations together; no research has been done that wasn't published by someone else, and some of it was shaky to begin with. I quote:
"Based on Wakefield’s* hypothesis involving the MMR vaccine as a possible factor in the cause of today’s iteration of autism (but not all of the disorders with ASD), [the company founder] decided to look carefully at the MMR vaccine as well as others.
...Since 1979 the MMR vaccine has contained hydrolyzed gelatin as a stabilizer. This fact may seem unrelated to the problem of autism unless the process of hydrolyzation is understood (i.e. concentration) and the fact that gelatin is a substance high in levels of glycine (approximately 21%).
In lay terms, the glycine is concentrated in this form of the gelatin, so presumably other kinds of gelatin have lower concentrations. Glycine seems to be related to glutamic acid (monosodium glutamate), which is a common food additive. I'm not sure exactly why the chemical makeup of glycine is thought to cause more problems than glutamate, because I'm not a biochemist; I think we can safely assume that since they are in the same family, it would make sense to investigate all of them.
Is the addition of gelatin to the MMR vaccine in 1979 (US patent 4,147,722 of April 3, 1979) merely coincidental with the increase in the rate of autism soon thereafter? Has the addition of hydrolyzed gelatin to some chicken pox vaccines compounded the problem? The challenges for the medical research community are now clear! Do certain classes of cells absorb substances? If so, the entire science of toxicology will change. If the homeostasis of certain classes of cells associated with bodily functions are disrupted, could the outcome be autism[?]; i.e. the inability of some cells to absorb the critical substances necessary for the brain and
body to function normally? Can a substantial imbalance between glutamate - gelatin/glycine cause autism by slowing or stopping the ability of certain cells to absorb substances in the brain and elsewhere in the body?"
Note the bold - they're not even sure that disrupted homeostasis causes autism (or if it's even correlated, if I'm reading that right). This is yet another unfounded leap. I'm not bashing unfounded leaps - they got us things like the chicken pox vaccine and penicillin, and an uninformed outside observer sees things the educated among us may miss. Still, it's a leap of faith to trust this connection at this point - it'd be like claiming faith in the single steel wire they use to run a suspension bridge cable, before the cable or decking have been put in place. It might hold weight, but it's not well supported.
In fact, nowhere does the release state that The Center is sure of this connection or that it is a single cause of autism:
"Applying The Center’s model for homeostasis of the body’s substances uncovered a few startling facts. First, several imbalances/disruptions in bodily processes appeared to be variables that contribute to autism. It became obvious that these variables have to occur concurrently for a “perfect storm” to cause the disorder. Simply, there was no one cause behind autism."
Simply, the fact that there is no one cause means that even if the hydrolized gelatin in the MMR vaccine turns out to be one single trigger, we may spend decades searching for the next half-dozen links which cause this "perfect storm", and in the meantime, someone is going to be blowing the single link we have out of proportion. One blogger for Autism awareness has already taken it and run with the title "Vaccines Cause Autism!". Seriously? This kind of sensationalism is damaging to the community and especially to already-scared parents who are looking to blame anyone and anything they can on the sudden disappearance of the child they thought they had. Let it go, dude. Vaccines cause immunity. Some unknown inability to process the outside world and/or respond to it in reliable ways causes autism, and denying your child an immunity to a trio of very serious and very real diseases because of some shady circuitous reasoning is stupid at best and possibly inhumane.
*Wakefield's hypothesis has been relatively well trounced since it came out, and is unpopular among many autism caregivers and doctors because it has caused a hole in immunity to MMR, which opens a lot of innocent kids up to serious health risks - these diseases are not gone, folks. They're only rare in developed countries because we vaccinate. See the Wiki entry's "Recent Studies" list for more information.