by Brita Belli

Parents of autistic children are encouraged when they witness improvements after eliminating gluten (wheat) and casein (dairy) from their kids’ diets. Now a parental study supports the correlation—for some kids on the autism spectrum, the gluten- and casein-free (GFCF) diet appears to be connected with remarkable changes.

Laura Cousino Klein, associate professor of biobehavioral health and human development at the Penn State College of Medicine, helped lead research that surveyed 387 parents or caregivers with affected children. For those diagnosed with combinations of autism and gastrointestinal issues or food sensitivities, the GFCF diet brought marked improvements in their autism spectrum disorder (ASD) behaviors—reducing hyperactivity and tantrums; minimizing constipation and seizures; and improving social behaviors.

Klein says scientists are still working to understand the interaction between the brain, gut and behaviors, but recent findings suggest that significant links exist. “One hypothesis is that by eliminating dietary triggers in the presence of food allergies or gastrointestinal distress, you’re reducing inflammation or irritability of the immune system, and that’s affecting the way the brain is functioning,” she says.

Dietary Turnaround One Racine, Wisconsin, mom, Cindy Schultz, a tireless advocate for her autistic son, says, “As an infant, he either had constipation or diarrhea. There was never a happy medium.” The GFCF diet has improved his health and his ability to communicate.

Shauna Layton, in Clinton, Indiana, says her son experienced similar bowel problems and she also saw a remarkable turnaround in his language abilities and social interactions as they adhered to a GFCF diet and eliminated sugar and yeast. Other parents from her online support group, Together in Autism, report similar success. “Some children have never talked, and now they are saying ‘Mom,’ ‘Dad,’ or ‘I love you,’ for the first time,” Layton says.

A definitive gut-brain link with autism has yet to be identified. Some scientists suggest that kids with autism are more likely to have leaky gut syndrome (intestinal permeability), which allows peptides from gluten and casein to escape from the digestive tract, cross the intestinal membranes, enter the bloodstream and go to the brain, causing the neurobehavioral symptoms known as ASDs, according to the American Academy of Pediatrics. While the AAP knows of no scientific proof that a GFCF diet will bring benefits, they note that it’s possible, especially in people suffering from celiac disease.

Parents have also observed that food dyes can exacerbate hyperactivity in children, a connection unconfirmed by the federal government. In 2011, the U.S. Food and Drug Administration Food Advisory Committee suggested further testing, while voting against additional food labeling requirements for potentially problematic dyes.

Meanwhile, some parents affirm that eliminating such dyes has helped them better manage their children’s attention deficit hyperactivity disorder (ADHD). A 2011 study taking into account 35 years of research found that many ADHD children showed significant improvement after eliminating dyes from their diets; it also registered that greater than 70 percent were positively influenced by various dietary changes. The results were promising enough for researchers to conclude, “A trial elimination diet is appropriate for children that have not responded satisfactorily to conventional treatment.”

The Role of Vitamin D A 2012 study in the Journal of Neuroinflammation found that autistic children had significantly lower levels of vitamin D than control subjects. Vitamin D, the study notes, regulates immune function and thus autoimmunity; when the immune system is disrupted and the body attacks itself, it may play a role in the development of autism.

Dr. John Cannell, founder of the nonprofit Vitamin D Council, remarks that fear of sun overexposure has led to the deficiencies. “Vitamin D is not a vitamin,” Cannell clarifies. “It’s a steroid hormone system that begins in the skin. If children aren’t getting any photons of UVB light, they’re not making any vitamin D.”

He notes that the rise in autism rates during the last 25 years tracks with increases in 50-plus SPF sunscreen use, more time spent indoors and a rise in breastfeeding. Because breast milk contains low amounts of vitamin D, since 2003 the AAP has emphasized the importance of parents giving vitamin D supplement drops to breastfed infants.

The same vitamin D study showed that the severity of autism correlated strongly with deficiencies of this vitamin and that the higher the level, the less severe the symptoms. Cannell has witnessed this phenomenon via a clinic hosted by the Vitamin D Council, recommending increases in vitamin D levels for autistic children to “high normal levels” and reducing vitamin A, which blocks the action of vitamin D.

“We have children on 5,000 to 10,000 units of vitamin D a day,” Cannell reports. “We see improvements in terms of sleep, meltdowns, eye contact, cognitive capacity, fine motor skills, language and reading—across the spectrum.”

Brita Belli is the author of The Autism Puzzle: Connecting the Dots Between Environmental Toxins and Rising Autism Rates.