How broccoli protects against cancer

SANTA BARBARA, Calif., Dec. 25 (UPI) -- U.S. researchers have discovered a cellular process that explains how cruciferous vegetables such as broccoli work to prevent breast cancer.

"Breast cancer can be protected against by eating cruciferous vegetables such as cabbage and near relatives of cabbage such as broccoli and cauliflower," first author Olga Azarenko of the University of California in Santa Barbara said in a statement. "These vegetables contain compounds called isothiocyanates which we believe to be responsible for the cancer-preventive and anti-carcinogenic activities in these vegetables."

Researchers at the University of California in Santa Barbara laboratories, led by Leslie Wilson and Mary Ann Jordan, said the isothiocyanate -- sulforaphane -- inhibits the proliferation of human tumor cells in a way similar to that in which anti-cancer drugs inhibit cell division during mitosis. Mitosis is the process in which the duplicated DNA in the form of chromosomes is accurately distributed to the two daughter cells when a cell divides.

While sulforaphane interferes with microtubule functioning during mitosis in a similar manner to anti-cancer drugs, it is much weaker than the drugs, and is therefore much less toxic.

"Sulforaphane may be an effective cancer preventive agent because it inhibits the proliferation and kills precancerous cells," Wilson said.