This research was done in a laboratory using cells, but the results support some other research finding that eating cruciferous vegetables frequently may help prevent cancer. They found that compound levels that were anti-cancer (killed off cancer cells) in this study could be achieved through diet alone. Cruciferous vegetables are vegetables of the family Brassicaceae (also called Cruciferae) such as cauliflower, cabbage, garden cress, bok choy, broccoli, brussels sprouts, kale, and similar green leaf vegetables. From Science Daily:
A compound and an enzyme that occur naturally in cruciferous vegetables--cauliflower, cabbage, broccoli and Brussels sprouts--may help prevent recurrence and spread of some cancers, according to researchers. When they treated human cervical cancer stem cells with phenethyl isothiocyanate (PEITC) in a Petri dish, about 75 percent died within 24 hours using a 20-micromolar concentration of the compound.
The precursor compound and enzyme in cruciferous vegetables combine during the chewing process to produce PEITC within the body, Dey explained. Though PEITC is a good candidate to develop as a dietary supplement, studies have also shown that sufficient cancer-preventing levels of PEITC can be achieved through diet alone.
When cancer is treated with chemotherapy or radiation, the tumor disappears but the cancer stem cells live on. "These cells are frequently resistant to conventional therapies," Dey said. Though cancer stem cells make up less than 5 percent of a tumor, they can regenerate the original tumor and migrate through the blood vessels spreading cancer to secondary locations."These tiny cells are very difficult to detect in a tumor," Dey pointed, adding that for a long time scientists did not even know they existed.
Based on information from scientific literature, the concentrations of PEITC that Dey and her team typically use in their research -- 5 to 15 micromolars -- may be achieved through diets rich in certain types of cruciferous vegetables, particularly land cress and watercress.