The radical organization whose supposed mission is to protect animal welfare now says that cow milk not only worsens autistic symptoms but can actually cause autism too. PETA’s campaign to stop people from using animal products latched on to obscure studies of dietary influences on autistic symptoms. A PETA blog post refers to two studies that found a link between autistic children’s behavior and consumption of cow milk (or proteins found in cow milk), and jumps to conclude that "dairy foods may worsen or even cause autism.”
One of the cited studies followed two groups of children, one of which had the kids on a gluten- and casein-free diet. The experimenters quantified poorly-defined things such as "whether the child at times could be aloof (1), was easily distracted (2), needed routines and rituals (3), and how the child responded to teaching.” The results section poetically describes how these traits were defined:
"Aloofness is a characteristic symptom in the behaviour of many people with autistic syndromes, reﬂected in the expression 'the child in the glass bulb'. The child is physically close, but yet impossible to reach. All the participants showed this trait prior to the experimental period"
Unnecessary literary attempts aside, this (and other) studies that found links between autism and diet were poorly designed. Anyone who’s ever given a kid a bag of M&M’s can tell you that diet can affect behavior, but there is no reason at all to believe that milk (or vaccines…) causes autism. Obviously parents should be wary of what their children eat. A bigger threat than milk proteins might be hormones that cows and chickens are fed, or pesticides that conventional fruits and vegetables are sprayed with. Trumping all these concerns might be Congress’s dubious ideas that tomato sauce or french fries count as servings of vegetables in school lunches; or the ever soaring numbers of prescriptions for drugs like Ritalin and Adderall, which act in the brain could have long-term developmental effects.