N-acetylcysteine (NAC) is an inexpensive antioxidant supplement that was recently examined for its ability to improve some aspects of autism. Significant improvements on some behaviors were observed with the use of NAC.
Dr. Hardan of the Department of Psychiatry and Behavioral Sciences at Stanford University in Stanford, California performed a randomized, placebo-controlled study of NAC in children with autism.
The children were divided into two groups, and one group received NAC, and the other received a placebo for 12 weeks. Patients who received NAC were administered 900 mg per day for four weeks, then 900 mg twice a day for four weeks, and then 900 mg three times per day for four weeks.
NAC treated patients had significant improvements in irritability compared to those on placebo. A decrease in repetitive/stereotyped behaviors was also observed, but reached statistical significance only on some subscales. Gastrointestinal side effects were observed, but NAC was generally well tolerated. The results were published in the journal Biological Psychiatry.
Autism may have several causes, and some of them include increased levels of the neurotransmitter glutamate, which is excitatory, and high oxidative stress. Researchers of the above study highlight one of the causes of the disease is disequilibrium between antioxidants and oxidants. This causes an increase in reactive oxygen species (ROS), and this causes damage to several cells and organs. Synthesis of glutathione, the body’s main antioxidant, is also perturbed.
NAC may work because it increases glutathione and beneficially modulates the release of glutamate. Whey protein can also raise glutathione levels, and other researchers have also previously found that NAC can raise glutathione.
A systematic review of research findings was carried out by Dr. Frustaci at the Unit of Clinical and Molecular Epidemiology at the Scientific Institute of Recovery and Treatment San Raffaele Pisana, Rome , which specializes in neurologic rehabilitation. Her key results recently published in the journal Free Radical Biology and Medicine shows that patients with autism have low blood levels of glutathione.
Other researchers also recently reported in the journal Current Medicinal Chemistrythat glutathione levels are reduced in autism patients, and antioxidant enzymes are decreased. They stated that glutathione can protect against the inflammation and oxidative stress in autism.
Thus, by increasing glutathione levels, NAC might improve some aspects of autism. Larger randomized studies are required to evaluate the effects of NAC on the disease.