Granpeesheh said she understands PETA's intentions of the possible benefits of the casein-free diet and pointing to milk, but she said the presentation is walking the line with how the information is perceived. "I think it's really brave of PETA, but I don't think you could say that there has been a link between cow's milk and autism."
But some parents, including Shelley Reynolds, president of Unlocking Autism, swear by the gluten-free, casein-free diet. Reynolds said she has seen a significant improvement in her child's language and motor skills after removing dairy products from her child's diet.
"Our point with the billboard is to let the parents of autistic children know that they very well may see an improvement in their child's symptoms if they remove dairy," responded Bruce Friedrich, vice president for PETA.
Freidrich claimed the benefits of limiting the consumption of milk for people with autism significantly improves their quality of life.
"It's kind of funny to imagine how anybody in the autistic support community could take issue with a campaign that educates people to help autism," Freidrich said.
Reynolds agreed, saying PETA's billboard is purely an awareness campaign of the stomach pain, diarrhea and behavioral reactions when some children with autism drink milk.
"There are not a lot of things you cannot control in autism, but you can control your child's diet," Reynolds said. "We don't hold parallel views with PETA, but I think that anything that sheds light on the autism crisis is awesome."
Michelle Guppy, who leads Texas Autism Advocacy in Houston, also agreed.
"If [the billboard] alerts parents to potential issues that are valid, then I don't much care who is putting the ad on," Guppy said.
The messenger does matter, Rubin said. He warned against trusting an animal rights group to make a collective recommendation for all individuals, including those without sensitivities to milk.
"I think this has more to do with 'milk is wrong' than getting it right with autism," Rubin said. "This latest billboard is the latest tangential attack, and I'm suspicious about what their ulterior motive is."