May 19, 2010 -- A popular diet intended to curb the effects of autism received yet another blow today in the form of a new study that found that autistic children who adhered to a gluten-free, casein-free diet showed no improvement in their symptoms.
Dr. Susan Hyman, lead author of the study, said she knows that some families would be surprised by the team's findings, especially given the reports of dramatic clinical improvement observed by many families using the diet.
"It would have been wonderful for children with autism and their families if we found that the GFCF [gluten-free, casein-free] diet could really help, but this small study didn't show significant benefits," Hyman, an associate professor of pediatrics at Golisano Children's Hospital at the University of Rochester Medical Center, said in a statement. But she did say it was possible that children with significant gastrointestinal disease would reap some benefits from the diet.
Still, Tracey McCollum, the mother of one of the children in the study, said the results were personally disheartening.
"We were hoping to show that the diet made a difference, give a lot of parents some hopes that, 'Here's a magic bullet; here is something that I can do proactively that will help my child," she said. "As a parent you want to do everything you can to help your child do the best he can in life."
The study will be presented May 22 at the International Meeting for Autism Research in Philadelphia.
The researchers undertook a randomized, double-blinded (meaning neither the participants nor the researchers knew which treatment anyone received), placebo-controlled study.
Fourteen children who were put on the diet for at least four weeks were then given snacks containing gluten, casein, both or neither. The researchers evaluated the children for changes in attention, sleep, stool patterns and characteristic autistic behavior. The study did not show significant changes in any of these symptoms for any of the groups.
Dr. Leonard Rappaport, chief of the Division of Developmental Medicine at Children's Hospital in Boston, called the findings "disappointing."
"Even though I did not believe it really made a difference, I was hoping I was wrong," Rappaport said.
Gluten-Free, Casein-Free Diet May Offer Little Help Against Autism
Dr. Ari Brown, a pediatrician and author of the books "Expecting 411," "Baby 411" and "Toddler 411," said that though she believes the study is "far from definitive," the results were not unanticipated.
"I have had many families who have tried GFCF diets and have not found a real difference in their children's behaviors," she said. "I do have a few who claim it does help, but those children also are involved in some behavioral therapy, so it is hard to tease out which treatment has been beneficial."
But David Amaral, president of the International Society for Autism Research and professor at the University of California at Davis, said that the findings may not necessarily be cause for dismay among parents of autistic children.
"Actually, I don't think that many parents will be disappointed," Amaral said. "On the contrary, it is very difficult to maintain children on the [GFCF] diet. Some parents who may have failed in maintaining the diet may feel relieved to hear that it might not be a benefit to their child even if they had persisted."
Gluten-Free Diets, Alternative Therapies, Commonly Tried for Autism
Many parents of autistic children look to alternative therapies, including special diets. According to Dr. Daniel Coury, medical director of the Autism Treatment Network, about 20 percent of parents within the the network use complementary methods to treat their autistic children, and more than half of them rely to some extent on diets.
In particular, parents of autistic children often report improvements with the popular but scientifically unproven gluten-free, casein-free diet.
This diet has been promoted by celebrities such as Jenny McCarthy, whose best-selling book, "Louder Than Words," detailed her use of diets as one way of treating her autistic son. Many autism communities have also touted the purported benefits of specialized diets for their children.
While many parents of children with autism report gastrointestinal pain in their children, the question remains whether the association between autism and bowel disease exists.
Some Parents Report No Success With Autism Diet
Not all parents have had success with the diets. Diane Marshall, 42, of Montclair, N.J., put her son David, 13, on a gluten-free, casein-free diet for a year when he was 4 years old. Marshall said she'd read success stories from some mothers who tried the diet for their autistic children. At the time, David had severe eczema and runny bowel movements, she said.
"We definitely thought the diet would help the autism," said Marshall.
Although the gastrointestinal issues subsided, Marshall said she did not attribute the end of her son's stomach problems to the diet. And she said the diet did not help her son overcome autism.
"There are a lot of things out there that are based on evidence, like teaching methods, that will help our kids a lot, but not diets," said Marshall.
"There has not been any research to substantiate the GFCF diet for children with autism who do not have celiac disease or wheat/milk allergies," said Dr. Stefani Hines, a development-behavioral pediatrician at William Beaumont children's hospital in Royal Oak, Mich.
But this does not mean that parents are necessarily empty-handed when it comes to scientific approaches to improving autism symptoms, Hines said.
"So far the research that has been the most promising has been aimed at applied behavioral analysis," she said. "We still have much to learn regarding best treatment practices for children with autism."
Study author Hyman said more research needs to be done in this area with similar rigor but with larger numbers, so that subtle effects can be detected. It's important, she said, for families to get the best information they can in deciding which interventions to pursue.
She also said families who elect to make dietary changes need to pay careful attention to general nutrition. "When you eliminate dairy as an entire category, you need to pay attention to vitamin D, calcium and protein," she said.
Guiding Parents Through Autism Options Important, Doctors Say
Rappaport agreed. "I hope that parents will go into these diets with their eyes open -- using a nutritionist to guide them -- and even if there seems to be anecdotal improvement, that they try the child off this restrictive diet after a while to see if it actually makes a difference."
In the meantime, Hines said doctors should not be surprised if parents continue to use the diet to try to improve autism symptoms in their children, despite the weight of the research.
"Autism is a chronic, lifelong condition with no known cure," Hines said. "Parents will continue to try everything out there to make sure they aren't missing anything that could possibly help their child.
"Our job as care providers is to help them along in this process and to try to wade through all the data with them to make the best-informed decisions. "