A chemical present in broccoli and some other vegetables, already touted as a cancer preventative, may reduce the behavioral symptoms of autism, findings of a clinical trial suggest.
In the trial involving 40 teenage boys and young men, improvements in their social interaction and verbal communication was seen after they were given daily doses of the chemical sulforaphane, researchers said.
Decreases were also seen in repetitive, ritualistic behaviors among the subjects, all of whom suffered with moderate to severe autism, the researchers from the Johns Hopkins University School of Medicine and Massachusetts General Hospital for Children reported in the Proceedings of the National Academy of Sciences.
"We believe that this may be preliminary evidence for the first treatment for autism that improves symptoms by apparently correcting some of the underlying cellular problems," says Paul Talalay, Johns Hopkins professor of molecular sciences and pharmacology.
Sulphoraphane, contained in cruciferous vegetables such as broccoli, cabbage and cauliflower, has been found in previous studies to inhibit some type of bacterial growth and has displayed the ability to slow growth in some cancers.
Researchers have been looking at the chemical's effect on the body's heat-shock response, the way it protects cells from stresses of high temperatures, such as when a person is suffering from a fever.
Many parents with autistic children have reported the autistic behaviors of their children decreased during fever, but returned when fever abated.
The researchers decided to test whether sulforaphane might improve the symptoms of autism by mimicking what occurs in the body during a fever.
"Stress is not all bad," co-investigator Dr. Andrew Zimmerman said, noting it can modify how some genes, possibly those involved in autism, are expressed.
Of those given the chemical in the trial, about two-thirds showed noticeable improvements in behavior, social interactions and level of calmness, they found.
"We could tell who was on it and parents could too," Zimmerman said. "There are several families who just can't stop praising it."
Compared to rapid changes in behaviors often seen with a fever, sulforaphane appears to result in more long-term, lasting effects on autism symptoms, the researchers said.
However, they acknowledged, once those in the trial were taken off the sulforaphane their autism symptoms slowly increased back to the level observed at the beginning of the study.
It would require larger and longer-lasting clinical trials to determine if sulforaphane could be utilized safely for long periods of time and whether there might be side effects, the researchers said.
"We are far from being able to declare a victory over autism, but this gives us important insights into what might help," Zimmerman said.
