Potent doses of broccoli sprout extract may help prevent cancer recurrence in survivors of head and neck cancer, giving credence to a new form of treatment known as “green chemoprevention,” a new study finds.

Head and neck cancer accounts for only 3 percent of cancer in the U.S., but about half of patients with it die within five years, a rate that has not changed in 50 years, statistics say.

Cruciferous vegetables, such as broccoli, cabbage and garden cress, have a high concentration of the naturally occurring molecular compound sulforaphane, which previously has been shown to protect people against environmental carcinogens, says Dr. Julie Bauman, one of the study’s lead researchers.

The findings come following tests on human head and neck cancer cells in the laboratory, which found that sulforaphane induced cells to turn on genes that promote detoxification of carcinogens, resulting in cancer protection, the researchers say.

Bauman was also involved in another study that found mice predisposed to develop this cancer but that were treated with this substance developed far fewer tumors than the animals that were untreated.

Also, in a small study, 10 healthy people drank or swished fruit juice mixed with broccoli sprout extract for several days. The volunteers had no significant problems tolerating the extract and the lining of their mouths showed that the same protective genetic pathway activated in the laboratory cell tests was activated in their mouths, meaning that the sulforaphane was absorbed and directed to at-risk tissue.

“With head and neck cancer, we often clear patients of cancer only to see it come back with deadly consequences a few years later," says Bauman. "Unfortunately, previous efforts to develop a preventative drug to reduce this risk have been inefficient, intolerable in patients and expensive. That led us to 'green chemoprevention'--the cost-effective development of treatments based upon whole plants or their extracts,” added Bauman of the study, which appears in Cancer Prevention Research.