It seems to me that a genuine hunt for whatever contributes to autism could do worse than sneaking a peak at artificial methionine.*
Methionine is one of the amino acids, a building block of tissue. Ever since the 1940s, it's been synthesised from such ingredients as propane to make a cheap supplement. However it wasn't in wide supply until the 1970s, when it suddenly became an increasingly widespread (and today practically ubiquitous) element of poultry feed. Notably, the use of chicken meat as a protein source has skyrocketed since the 1970s, as has autism.
Unfortunately artificial methionine is subtly different from the type naturally used for animal tissue -- that is, the artificial substance occurs in a mirror image of left and right handed molecules (or 'racemes'). The only form of methionine that can be used to make animal tissue is the left handed (or 'L') version. Thus an animal must convert the 50% that is right handed to L-methionine. This conversion is about 90% in chickens and from my reading approximately 30% in humans (that is, leaving a percentage unconverted).
It's unknown to my research if some of the right handed methionine stays in a chicken carcass and enters the human diet, but reasonable to presume it would. Given the low human conversion rate, this would surely produce elevated blood methionine.
Now here's the alarming part: elevated blood methionine is associated with dementia. The question is whether, by similar processes, it may be related to autism?
Most interestingly, methionine seems to connect (at least to my reading) with every area found to be faulty in autism. Ordinarily, methionine is used to make tissue-building amino acids and also important sulphur compounds (such as those involved in heavy metals detoxing). Methionine requires vitamin B-12 to be converted into other compounds, and an excess of methionine can lead to B-12 shortage. Autistic children appear to have a problem detoxing heavy metals, have a B-12 shortage (or at least, like dementia, can be improved by high B-12 doses), and usually have improper sulphur levels. I haven't read whether autistic children have elevated methionine, but it would be very interesting indeed to find out.
Are these enough reasons to call for an examination of our most popular meat, and the feeding practices that have developed in the quest for cheap food?
Or is commercial science looking after us perfectly well, and it's just our genes that aren't behaving properly?
I know one thing: my genes have been around for thousands of years, while artificial methionine has been around for about as long as autism.
*For this post, all my citations will be on my other blog: see http://naturalchicken.blogspot.com/ and look to the post titled 'artificial methionine: is it safe?', usually sitting among the 'most popular' to the right.