Autism and diet: Many questions to digest
Last week, the British medical journal the Lancet, which had originally published a controversial 1998 study by British researcher Andrew Wakefield that implied a link between autism and the vaccine for measles, mumps and rubella, formally retracted that study. In the wake of this, one of the tantalizing areas to be explored is the role diet might play in the lives of children with autism.
Research published in October showed that 1 in 91 children has a disorder somewhere along the autism spectrum, with degrees of severity ranging from mild to major. (Federal figures released in December put that number at 1 in 110.) For now, the only treatment known to help kids with autism -- the most common of the conditions that make up what is known as autism spectrum disorder (ASD) -- is placement in an education program that's appropriate to their specific needs, providing speech and language therapy to boost their ability to communicate, and helping them develop social skills, according to Susan Levy, director of the Regional Autism Center at the Children's Hospital of Philadelphia and a member of the American Academy of Pediatrics' autism subcommittee.
But legions of worried and desperate parents and even some physicians have put stock in other remedies, many of them food-related. Some have believed there's a connection between autism and gastrointestinal problems, which was first suggested in the discredited 1998 paper. "The presumed mechanism of action was that people with autism have a leaky gut, which led to abnormal absorption of some of the breakdown products of gluten and casein," Levy explains. That abnormality, in the leaky-gut theory, would allow those byproducts to be absorbed into the bloodstream and somehow cross into the brain.
Research published in January found no evidence of a gastrointestinal syndrome specific to autism. Still, Levy notes that special diets are one of the most common treatments used by parents. Those decisions, she says, often are influenced by media reports touting the diets' effectiveness. However, she says, "we don't know the true prevalence of gastrointestinal symptoms in kids with autism."
Many parents and other advocates maintain that removing gluten (found in wheat, barley and rye) and casein (found in dairy products) alleviates autism symptoms. Some, such as actress Jenny McCarthy, an activist and parent of an autistic child, have claimed to remedy the condition through diet and avoidance of vaccination. For kids with ASD who are also sensitive to gluten or casein, Levy says, removing those triggers from the diet "calms them down, removes some symptoms and makes them able to function better," which might prompt hopeful parents to believe the new diet has had a direct effect on the autism.
Whether diet plays a role in causing or managing autism, it's essential for parents to make sure their children get adequate nutrition, as being generally well-nourished can help relieve stress and other underlying factors that might make symptoms of the disorder seem worse.
That can be tricky, as children with autism, like any children, can be picky eaters, some preferring to stick to a few favorite foods to the exclusion of others. A child with ASD, Levy says, might have some sensory hypersensitivity that causes him or her to prefer certain foods and shun others; such a "picky" eater might become constipated, which in turn can make a child inclined to avoid eating.
"It can be a vicious cycle," Levy says, "and we don't know whether the picky eating is the cause or the effect." Complicating matters, kids with autism often have difficulty communicating.
Megan Hart hopes her new book, "The Everything Guide to Cooking for Children With Autism," strikes the right balance between providing nutritional guidance and endorsing a restrictive diet. Hart, a pediatric nutritionist, says, "I really had to think long and hard" when she and co-author Kim Lutz were asked to write the book. "The science is still developing," she says. "But I also know that for many parents of children with autism, this is something they want to try because of things they've read in the media, seen on the Internet or heard from other parents."
Hart's aim was to provide for families that want to attempt a gluten-free, casein-free diet "a resource to do it safely, with good, kid-friendly recipes to try." She advises that children be monitored by a physician as they try such a diet and that the diet be just one component of an overall treatment plan. "It's a very difficult diet to do successfully," Hart says. And, she adds, "People either respond to this diet or they don't. It helps some people, but not everybody."
Much research is underway with regard to special diets' effects on autism, Levy says. "Hopefully we'll know more in a year or so," she says. In the meantime, she's not convinced that we've seen the last of the vaccine-autism connection. "Those kinds of things don't really die," she says. "They go underwater and resurface sometime later."