In a small placebo-controlled trial, sulforaphane supplements eased autism symptoms in nearly half of those treated
(Oct. 13, 2014) Results of a small clinical trial suggest that a supplement derived from broccoli sprouts can ease the core symptoms of autism in some people with the disorder. The chemical – sulforaphane – is best known from studies suggesting that it helps prevent certain cancers.
The report appears online in the Proceedings of the National Academy of Sciences.
The study involved 40 boys and young men, ages 13 to 27, with moderate to severe autism. Of these, 29 were randomly selected to receive the supplement (50 to 150 µmol depending on weight). The others received a look-alike placebo, or “dummy” capsule. Neither the researchers nor the participants and their families knew who received the actual treatment until after the trial concluded.
Before starting the trial, the participants’ parents and physicians filled out three standard behavioral assessments that measure sensory issues, ability to relate to others, communication skills, sociability and other behaviors related to autism. The researchers repeated these assessments at 4, 10 and 18 weeks of treatment, then once more four weeks after the treatment stopped. Of the 40 participants who began the trial, 37 remained through the final assessment.
Nearly half respond to treatment
The results of the 18-week assessment showed that:
* 46 percent of those who received the active treatment had significant improvements in social interaction.
* 42 percent had significant improvements in verbal communication.
* 54 percent had substantial decreases in abnormal behaviors.
Most of these individuals began showing improvements during the first four weeks and continued to improve during the rest of the treatment. This included improvements in irritability, lethargy, repetitive movements, unusual mannerisms, hyperactivity, awareness and communication.
Four weeks after the treatment stopped, evaluations showed autism symptoms returning to pre-treatment levels.
By contrast, the boys and men who received the dummy treatment showed little or no change at any point during the study.
“While this study is too small and preliminary to prove that sulforaphane helps treat autism, the findings are interesting and important,” comments Paul Wang, Autism Speaks senior vice president and head of medical research. (Dr. Wang was not involved in the study.) “We hope that the authors and other researchers will follow-up with larger studies that can address unanswered questions and potential safety issues.”
One potential safety issue emerged, Dr. Wang notes. Two of the individuals receiving the supplement had seizures during the trial. Both had a history of seizures. So this might have been coincidence. However, none of those receiving the placebo had seizures during the study.
"We are far from being able to declare a victory over autism, but this gives us important insights into what might help," says co-investigator Andrew Zimmerman, a pediatric neurologist at UMass Memorial Medical Center.
Parents noticed behavioral changes
Dr. Zimmerman adds that before they learned which subjects got sulforaphane, both researchers and parents noticed striking changes in 13 of the participants. These changes included looking others in the eye and shaking hands for the first time. At the end of the trial, it turned out that all 13 of these individuals had been taking sulforaphane.
Researchers speculate on chemical’s action
"We believe that this may be preliminary evidence for the first treatment for autism that improves symptoms by apparently correcting some underlying cellular problems," says co-author Paul Talalay.
Specifically the researchers speculate that sulforaphane may correct autism-related biochemical problems at the level of the brain cell. These problems may relate to the efficiency of mitochondria – tiny organelles that supply a cell with energy.
Dr. Talalay has been studying sulforaphane for decades. In 1992, his research group found evidence that the chemical bolsters the body's natural defenses against inflammation, DNA damage and oxidative stress. Studies have linked these problems to mitochondrial dysfunction.
Later, the team found evidence that sulforaphane likewise improves the body's heat-shock response. This chemical response protects cells from the stress caused by high temperatures, including fever.
Previous research on fever
In 2007, Dr. Zimmerman investigated the commonly reported anecdote that autism symptoms temporarily improve when some children have a fever. He found such reports to be true. However, the mechanism behind fever’s effect on autism symptoms has not yet been identified.
Because sulforaphane, like fevers, initiates the body's heat-shock response, Drs. Zimmerman and Talalay wondered if sulforaphane could produce the same temporary improvement in autism symptoms. Their current study was designed to test this idea.
In fact, 32 of the study’s participants had a history of fever-produced improvements in symptoms, as reported by their parents. Sulforaphane, like fever, may temporarily help brain cells to cope with their “handicaps," Dr. Talalay speculates.
Talalay cautions that broccoli sprouts and mature broccoli don’t contain the levels of sulforaphane present in the supplements used in the study. As such, it’s unlikely that eating large amounts of broccoli or other cruciferous vegetables would produce the same effect.
The authors also disclose that their institution has a licensing agreement with Brassica Protection Products, which makes a sulforaphane supplement. As part of this agreement, Johns Hopkins is entitled to royalty on the sale of products described in the study. The university also owns Brassica Protection Products stock. The university declares that it is managing these arrangements in accordance with its conflict of interest policies.
Also see, "Broccoli Sprouts for Autism? What You Need to Know" in the Got Questions? blog.
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