Autism – often referred to as autism spectrum disorder, or ASD – is a neurodevelopmental disorder characterized by impaired social interaction and communication, as well as restrictive, repetitive patterns of behavior. The disorder typically manifests in early childhood and is slightly more common among boys than girls. Roughly one in 54 people living in the United States has ASD. Findings from a recent clinical trial suggest that sulforaphane improves behavioral symptoms associated with autism.

Sulforaphane is a bioactive compound derived from precursors (glucoraphanin and myrosinase) in broccoli and broccoli sprouts. It exhibits antioxidant and anti-inflammatory properties and may be beneficial against a wide range of chronic and acute diseases, including cardiovascular disease, neurological disease, cancer, and others. Previous research has demonstrated that sulforaphane reduces behavioral symptoms of autism in young men. Sulforaphane exerts its therapeutic effects through a variety of mechanisms, the most notable of which is the activation of Nrf2, a cellular protein that regulates the expression of antioxidant and stress response proteins that provide protection against oxidative stress due to injury and inflammation. Sulforaphane is the most potent naturally occurring inducer of Nrf2.

The randomized, placebo-controlled trial, which involved 45 children (ages 3 to 12 years) with autism, occurred in three distinct phases. During the first phase, half of the children received a commercially available dietary supplement containing glucoraphanin and myrosinase (yielding approximately 15 micromoles of sulforaphane) every day for 15 weeks, while the other half received a placebo. During the second phase, which also lasted 15 weeks, all the children received the supplement. During the third phase, which lasted six weeks, none of the children received the supplement. Before and after the intervention, caregivers and investigators evaluated the participants' symptoms using standardized behavioral assessments. Investigators collected blood and urine samples from the participants to assess metabolic and biochemical changes.

They found that behavioral symptoms among the children who received the sulforaphane supplement improved during the first phase (compared to those on the placebo), but the differences between the two groups were not statistically significant. However, both groups' behavioral symptoms improved during the second phase, as did markers of oxidative stress, mitochondrial respiration, inflammation, and heat shock proteins. The supplement elicited no adverse effects and was well tolerated.

These findings suggest that sulforaphane improves behavioral symptoms associated with autism. However, the study investigators caution that further study is needed to fully elucidate the clinical effects and mechanisms of action associated with the compound’s effects on autism.

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• Learn more about the effects of sulforaphane on autism in this episode featuring Dr. Jed Fahey.