Chemical in broccoli sprouts may treat autism

"We are far from being able to declare a victory over autism, but this gives us important insights into what might help," says Andrew Zimmerman. (Credit: Diarmuid/Flickr)

A chemical found in broccoli sprouts appears to improve some symptoms of autism.

The study involved 40 teenage boys and young men, ages 13 to 27. Those who took the chemical, called sulforaphane, showed improvements in social and verbal skills compared to people who took a placebo. Researchers also saw a decrease in repetitive, ritualistic behaviors.

“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, professor of pharmacology and molecular sciences at Johns Hopkins University, who has researched compounds like sulforaphane for 25 years.

“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, professor of pediatric neurology at University of Massachusetts Memorial Medical Center.

The root causes of ASD remain elusive, but progress has been made, Talalay says, in finding biochemical and molecular abnormalities that accompany autism, many related to the efficiency of energy generation in cells.

The fever effect

Studies show that the cells of those with ASD often have high levels of oxidative stress, the buildup of harmful byproducts from the use of oxygen. That stress can cause inflammation, damage DNA, and lead to cancer and other chronic diseases.

In 1992, researchers discovered that sulforaphane has some ability to bolster the body’s natural defenses against oxidative stress, inflammation, and DNA damage. In addition, the chemical later turned out to improve the body’s heat-shock response—a cascade of events used to protect cells from the stress caused by high temperatures, including those from fever.

Intriguingly, about half of parents report that children’s autistic behavior improves noticeably when they have a fever, then reverses when fever abates. In 2007, Zimmerman tested this anecdotal trend clinically and found it to be true, though no explanation was identified.

Because fevers, like sulforaphane, initiate the body’s heat-shock response, Zimmerman and Talalay wondered if sulforaphane could cause the same temporary improvement in autism that fevers do. The study, published in the Proceedings of the National Academy of Sciences, was designed to find out.

Improved in four weeks

Before the trial, the patients’ caregivers and physicians filled out three standard behavioral assessments that measure behaviors related to autism. Twenty-six subjects were randomly selected to receive, based on their weight, 9 to 27 milligrams of sulforaphane daily, and 14 received placebos.


Most of those who responded to sulforaphane showed significant improvements within four weeks and continued to improve during the rest of the treatment.

After 18 weeks, sulforaphane patient scores on two of the three assessments had decreased 34 and 17 percent, respectively, with improvements in bouts of irritability, lethargy, repetitive movements, hyperactivity, awareness, communication, motivation, and mannerisms.

On the third assessment, 46, 54, and 42 percent of sulforaphane recipients improved noticeably in social interaction, aberrant behaviors, and verbal communication, respectively.

The scores of sulforaphane patients reverted toward original values after they stopped taking the chemical.

“It seems like sulforaphane is temporarily helping cells to cope with their handicaps,” Talalay says.

It would be very difficult to achieve the levels of sulforaphane used in the study by eating large amounts of broccoli or other cruciferous vegetables, Talalay notes. The test subjects took sulforaphane-rich broccoli sprout extract administered in capsules.

Researchers from Harvard University Medical School were coauthors of the study. The Nancy Lurie Marks Family Foundation, the Hussman Foundation, the Lewis B. and Dorothy Cullman Foundation, the Agnes Gund Foundation, the N of One Foundation, and the Brassica Foundation for Chemoprotection Research provided funding.

Source: Johns Hopkins University