Milk Doesn’t Aggravate Autism: How PETA and Jenny McCarthy Became Unwitting Bedfellows

Autism pseudoscience is back in the news, and this time ice cream is the scapegoat. According to the animal rights group PETA, childhood autism may be diminished with a dairy-free diet. While this is not a new campaign (it appears to have debuted in 2008), PETA recently made headlines as scientists and others pointed out there is no established correlation between dairy and autism. In fact, any such correlation has been roundly debunked.

The Gluten-Free-and-Casein-Free-Diet (GFCF Diet for short) originated in the early 90s, and became popular among families living with autism after the 1998 publication of Special Diets for Special Kids, a book about using dietary restrictions to treat developmental disabilities. It waas this book that made notorious “anti-vaccination” spokesperson^[1] Jenny McCarthy suspect inoculations caused her son’s developmental disability.

“What I got from the book was Evan was born with a weaker immune system; getting vaccinated wreaked havoc in his body, and mercury caused damage to the gut (the gut being the home base for your immune system), which caused his inability to process certain proteins, and one could see the result of this damage when he consumed wheat or dairy. Through removing wheat and dairy, this book proposed, some of these behaviors [Evan’s symptoms] could dissipate or disappear.” - Jenny McCarthy, Louder than Words

PETA and others pushing a vegan diet to cure autism may not realize their position is inextricably linked to anti-vaccine activism, which has been responsible for dramatic upsurges in deadly and preventable diseases in recent years. The CDC recently blamed anti-vaccination activism in part for the highest measles rates in twenty years. Suggesting that dairy makes autism symptoms worse sends new parents down a rabbit hole of dangerous claims, from the relatively innocuous “go easy on the gluten” to the quasi-homicidal “beware of vaccines.”

But all of that might be justifiable if dairy did, in fact, cause autism or even worsen it. It doesn’t. When pressed for evidence, PETA and others trot out a few anecdotes and the same couple of small-scale studies claiming to show that autistic kids who went on a GFCF diet showed significantly reduced symptoms. However, these studies are incredibly old (one is almost two decades old) and have major flaws. The first was only single-blinded. The parents who were responsible for reporting whether their child improved knew whether the kid received treatment or not. And the second didn’t actually find a direct correlation between milk intake and autism symptoms. When the studies were repeated and these flaws fixed, the positive effect went away completely or was so weak as to be a non-starter. The American Academy of Pediatrics states that, at best, they can’t recommend a GFCF diet to treat autism. And this should matter to PETA, since they seem to take the AAP as experts on PETA’s own website, noting that the organization warns not to give cow’s milk to infants.

Since the recent press attention, social media has been aflutter with users asking PETA why they would still make this (at best) outdated autism claim. Most who tweeted at the organization received a response like this:

The link leads to a site where PETA summarizes their evidence, citing the two ancient studies but paying more attention to the stories parents have told: “The Internet contains numerous heart-wrenching stories from parents of kids who had suffered the worst effects of autism for years before dairy foods were eliminated from their children’s diets.” Presumably, the organization would not accept Internet comments as sources if the parents had said it was pork that cured their child’s autism.

In Louder than Words, McCarthy describes her heartbreaking tale of trying to understand her son’s disability, starting with seemingly endless seizures at age two. After a harrowing hospital experience makes her lose faith in doctors, and after being forced to wait months for the proper behavioral treatments, McCarthy turns to several spiritual healers, including two Mormon missionaries who predict her son will be better “in a year’s time,” and submerses herself in internet research. “It was time to dig and get my doctorate from the University of Google,” she says. In the end, she subjects her child to chelation therapy, hyperbaric oxygen chambers, and a barrage of other alternative treatments. McCarthy’s science education has clearly failed her (and by extension, her son). Likewise, the evidence provided on PETA’s site indicates that science isn’t their strong suit either, however much good they do otherwise.

I stopped buying dairy products eleven years ago for animal welfare reasons. I also don’t buy meat or eggs. My diet is, for the most part, vegan. There are plenty of good reasons people choose to avoid animal products, from animal protection to reduced risk of cardiovascular disease and obesity ^[2] to curbing climate change.^[3] But these bonus issues have the benefit of being evidence-based. Dairy, on the other hand, doesn’t cause or aggravate autism, and claiming that it does indirectly supports the same deadly pseudoscience that has created massive outbreaks of horrifying diseases. PETA would do well to retract their claim and apologize to the parents of autistic children. And maybe send some coupons for soy ice cream.