Evidence lacking for special diets in autism

CHICAGO — An expert panel says there's no rigorous evidence that digestive problems are more common in children with autism compared to other children, or that special diets work, contrary to claims by celebrities and vaccine naysayers.

The report's lead author, Dr. Timothy Buie of Harvard Medical School, said pain or discomfort because of bloating or stomach cramps can set off problem behavior, further complicating diagnosis, especially if the child has trouble communicating — as is the case for children with autism.

Autism is a spectrum of disorders affecting a person's ability to communicate and interact with others. Children with autism may make poor eye contact or exhibit repetitive movements such as rocking or hand-flapping.

About 1 in 110 U.S. children has autism, according to a recent government estimate.

More than 25 experts met in Boston in 2008 to write the consensus report after reviewing medical research. The Autism Society and other autism groups funded the effort but gave no input.

The report refutes the idea there's a digestive problem specific to autism called "leaky gut" or "autistic enterocolitis." The hypothesis was first mentioned in 1998 in a now-discredited study by Great Britain's Dr. Andrew Wakefield. His paper tied a particular type of autism and bowel disease to the measles vaccine.

The new report says the existence of autistic enterocolitis "has not been established."

It calls for more rigorous research into the prevalence of digestive problems and whether special diets might help some children.

For now, the report states, available information doesn't support special diets for autism.

Diets have been promoted by actress Jenny McCarthy, whose best-seller "Louder Than Words" detailed her search for treatments for her autistic son.

Nearly 1 in 5 of children with autism is on a special diet, according to a project that tracks what treatments parents are trying. Most of them were on diets that eliminate gluten, found in many grains, or casein, a protein in milk, or both, according to the Interactive Autism Network at the Kennedy Krieger Institute in Baltimore, Md.

The new report advises doctors to watch for nutritional deficiencies in patients with autism. It recommends a nutritionist get involved if a patient is on a special diet or eats only certain foods.

Lee Grossman, president of the Autism Society, a funder, said many doctors have written off autistic children's digestive problems as untreatable.

"I think we still have a lot to learn about the gut and how it contributes to behavioral symptoms," Grossman said. "We have a lot to learn about how to treat this."

Buie said his clinic has various techniques for treating children with problem behavior. They schedule early-morning appointments so children aren't delayed in the waiting room or blow bubbles during a blood draw as a distraction. As a last resort, they use anesthesia.

"If a child is going to be asleep because of a dental evaluation or an MRI study, we will do our endoscopy, our blood work, spinal tap, haircuts or teeth cleaning at the same time," Buie said. "Our nurses do beautiful haircuts."