The double-blind clinical study, which is being carried out by researchers at the University of Texas Medical School in Houston, is part of a number of trials looking to shed light on the true impacts that some foods may have on the neurobehavioral disorder.
According to specialist UK-based charity, the National Autistic Society (NAS), many parents of children with the disorder have considered turning to diets free from either gluten or dairy produce, with reports of varying levels of success.
With the dairy industry increasingly keen to play up the health and nutrition benefits of their products, the research could have major impacts on current nutritional advice for consuming such goods and has been welcomed by some of its members.
“Most of the studies conducted to date in this area have not been well controlled and have not provided the strength of evidence needed to justify removing two nutrient rich food groups important in children’s growth and development,” stated Judith Bryans of the UK-based Dairy Council.
“The recommendation to remove dairy and gluten from the diets of autistic children has not been approved by the medical community who to date do not believe that there is enough evidence to show overall that elimination diets are an effective treatment for autism.”
According to the researchers, previous studies have found differences in the central nervous systems of those diagnosed with the disorder to those without the condition. However, the cause of autism remains unknown and is suspected to be the result of a mixture of genetics and environment some studies have said.
Lead researcher Fernando Navarro said that a better understanding of the causes of the disorder, which has been linked in some cases to negatively affecting brain development, was vital.
Navarro said that an estimated six in every thousand children were currently affected by autism.
“There’s a lot of misinformation, so that’s why this study is so important,” he stated. “Hundreds and hundreds of parents think this works, but we need serious evidence.”
Katherine Loveland, co-researcher on the project and a professor of psychiatry and behavioural sciences, said that links have been previously made between children with autism and gastrointestinal problems like constipation and diarrhoea.
Loveland added that the full impact of these problems on brain development was uncertain particularly in terms of being detrimental or beneficial to behaviour.
“There are neurotransmitters and neuroreceptors in the gut that correspond with those in the brain,” she stated. “There are some scientific reasons to think that some kids may benefit from this diet.”
The four week-long project, funded in part by the Department of Paediatrics, will draft 38 children diagnosed with autism between the ages of three and nine to test the impacts of both gluten and milk proteins on intestinal function.
Before testing is expected to commence, the subjects will be required to cut gluten and dairy products from their diets. Gluten, which is a protein in wheat, and casein and whey proteins in milk in the respective form of gliadomorphin and casomorphin peptides are thought to impact behaviour, the researchers claim.
To test this, intestinal permeability, also known as leaky gut, will be measured by urine collection, and behaviour responses will be recorded through psychometric testing.
News of the research has been welcomed by the NAS, which claims that there is currently insufficient evidence on the impact of diet on autism, which has led to uncertainty over causes of the disorder.
The organisation’s director of communications said that there had been cases where concerns over children’s bowel problems were being dismissed as hysteria or an untreatable result of autism.
“It is vital that any suspected gut or bowel problems are investigated thoroughly and promptly, and where necessary referred on for specialist advice and treatment,” stated Benet Middleton.
Middleton added that when it came to dietary intervention, people with autism responded in unique and varied ways and research could not be generalised.
In a previous year-long trial into the impact of casein and gluten free diets on people with autism, it was suggested that there was a link between consumption and urinary peptide abnormalities.
These abnormalities, according to the same research, could be linked to behaviour in cases of diagnosed autism. However, the researchers claimed that further research was needed to find what types of people may actually benefit, if at all, from such diets.