Recent findings from a randomized clinical trial offer hope that a promising treatment may be on the threshold. A chemical derived from broccoli sprouts, called sulforaphane, was tested in a placebo-controlled clinical trial that entered 44 young men (aged 13-27) with Autism Spectrum Disorder (ASD) They were treated with sulforaphane (29 men) or placebo (15 m3n) for 18 weeks , then followed up for another 4 weeks.
The behavioral outcome measures included social responsiveness and aberrant behaviors associated with ASD.
Results: Participants who received the sulforaphane showed significantly greater improvements than those who received the placebo for the core ASD symptoms of stereotypy, hyperactivity, irritability, lethargy, and deficits in communication, motivation, and awareness.
These improvements were observed as early as 4 weeks after treatment, and throughout the trial, including at the end of the 18 week treatment, and when measured 4 weeks after the end of treatment.
The drug showed low toxicity. None of the blood laboratory results were outside the normal range throughout the trial. Adverse events were observed during the trial, but the frequency was not significantly different among those who received the sulforaphane or the placebo treatment. Seizure occurred in two of the 29 men who received sulforaphane, both of whom had a history of seizures. Thus, while suggesting the need for clinical monitoring, it is not clear that these events were consequences of sulforaphane.
Significance: Autism research has yet to identify treatments that successfully target the core clinical features (difficulties in social interaction and repetitive, stereotypical behavior) and the fundamental biochemical abnormalities of ASD. Existing treatments ameliorate troublesome associated features, but not the central diagnostic features of ASD. (These treatments include early behavioral intervention through Adaptive Behavioral Analysis and the medications risperidone and aripiprazole.)
Although the findings are promising, this sulforaphane trial is only one study and the sample size of 44 men is small. Much more research must be done to find out how the trial’s results will apply across the heterogeneous spectrum of persons with autism, and in females with ASD. Still, the observed clinical improvements in behaviors central to ASD offer leads for further investigations into the underlying pathophysiology of ASD and the discovery of new drugs for treating and possibly preventing ASD.
Read the full trial report in the Proceedings of the National Academy of Science (PNAS), October 13, 2014. Authors: K Singh, SL Connors, EA Macklin, KD Smith, JW Fahey, P Talalay & AW Zimmerman.