Stanford, CA—A new study shows that an antioxidant supplement may be useful in addressing certain aspects of autism. The data, published in Biological Psychiatry, were collected by a team from Stanford University School of Medicine and Lucile Packard Children’s Hospital.

According to the National Autism Association, autism is a “neurodevelopmental disorder characterized by social impairments, cognitive impairments, communication difficulties and repetitive behaviors.” Males are four times more likely to have it than females, and it can range from very mild to very severe. Irritability, aggression and mood swings are all characteristics of autism and are treated with antipsychotics, which do not address certain symptoms like repetitive behavior.

The researchers focused on N-acetylcysteine (NAC) as a dietary supplement. The study included children with autism ranging from ages three to 12 years old. All participants were physically healthy and not planning to change anything about their treatments during the trial. The study had a double-blind design, and had the children receive either NAC or a placebo for 12 weeks. Participants were evaluated before and after the trial and every four weeks during it. They were tested using several standardized surveys that measured problem behaviors, autistic preoccupations, social behaviors and side effects of the drug itself.

Overall, researchers found that NAC decreased irritability scores from 13.1 to 7.2 on the Aberrant Behavior Checklist. Irritability affects 60–70% of children with autism, and describes actions such as throwing, kicking, hitting and yelling. In addition, NAC decreased the repetitive and stereotyped behaviors.

How did it work? Researchers hypothesized two possible mechanisms. NAC may protect neurons by raising levels of glutathione, a protective antioxidant metabolite. Past studies suggest glutathione is lacking in autistic children. Other research has found that autism is related to an imbalance in excitatory and inhibitory neurotransmitters in the brain. NAC changes the glutamatergic family of excitatory neurotransmitters, which can be useful in autism care. NAC still needs to be confirmed by a larger trial before it can be recommended for children with autism.

Antonio Hardan, M.D., study lead author, associate professor at Stanford and director of the Autism and Developmental Disabilities Clinic at Packard Children’s Hospital, notes there are differences between NAC supplements sold at retail and that used in the study. The NAC used in the study were individually packaged doses, while the over-the-counter is packaged in a bottle. Once the bottle is opened, the pills are exposed to air and sunlight, causing oxidation, which could make them less effective.


Published in WholeFoods Magazine, August 2012 (online 6/29/12)