Cauliflower and cabbage contain sulforaphane, a chemical that can improve autism symptoms. Adults given sulforaphane showed improved behavior and communication within four weeks. Two-thirds of those with autism spectrum disorders were less irritable, more motivated, and had fewer repetitive behaviors after treatment. After 18 weeks, scores on assessments of irritability and social skills decreased by 34% and 17% respectively for those receiving sulforaphane, indicating overall improvement in symptoms.