This is part of a huge comment I made at Autism Diva, which resulted in my actually starting to blog on the subject:
Anecdotal: I realized I had a gluten intolerance long before I ever heard of Asperger's. My son and I have not been officially diagnosed, but we meet a good proportion of the criteria for a diagnosis of Asperger's Syndrome. He also has a gluten intolerance. We're also both part Irish. My gluten intolerance did not show up until I was twelve, my son's until he was ten.We don't seem to have any problems with dairy.My family physician and his pediatrician have approached the problem this way: if cutting the item out of the diet ends the unpleasant symptoms, then you're probably allergic or intolerant. Doing a biopsy may make it official, but it's a dangerous procedure just to make a definitive diagnosis when the problem will be treated in the same way after the diagnosis as it was before.
There's an incredibly high rate of gluten intolerance and celiac disease among the Irish. Why? It's probably related to the low levels of wheat in the diet of the Irish. Even when Ireland was basically a wheat factory for England, nearly all the crop was exported by the English landholders. That's why the Irish became so dependent on the potato. It's quite possible that a higher level of wheat in the diet would either have resulted in a better adaptation, or simply killed off the segment of the population that could not digest the gluten.
Is there a higher level of ASD among the Irish? I don't know. They seem to have a higher rate of eccentricity, insanity, genius and misery. Autism? Asperger's? Maybe.
Or maybe it just happens that the gluten intolerance makes us a little bit off mentally.
What I have found is that nearly any type of vegetable protein causes problems for me. This includes MSG, that lovely soy protein derivative. This also means I won't be a vegetarian unless it's forced on me, as gluten and soy are huge parts of many vegetarian diets.
Maybe this way I can avoid being a real autistic (as determined by David Kirby) by not having diarrhea pouring down my legs. Wow. I didn't know it was so simple.