Cancer Health Center

Is There an Anticancer Diet?

Vegetables for Bladder Cancer Prevention

Raw cruciferous vegetables such as broccoli, broccoli sprouts, cabbage, and cauliflower seem to reduce bladder cancer risk by about 40%, researchers from Roswell Park Cancer Institute in Buffalo, N.Y., reported at the meeting. That's due to compounds they contain called isothiocyanates or ITCs, thought to be protective against bladder cancer.

"Raw cruciferous vegetables are better than the cooked vegetables because cooking time reduces the amount of isothiocyanates by 60% to 90%," says Li Tang, MD, PhD, a postdoctoral fellow at Roswell Park who led one of the studies.

Her team surveyed the eating habits of 275 people with a diagnosis of bladder cancer and 825 healthy people. They asked them about pre-diagnosis intakes of raw and cooked vegetables, their cigarette smoking habits, and other risk factors.

Nonsmokers who ate at least three servings a month were about 73% less likely to develop bladder cancer than those who smoked and ate less than three servings a month.

Broccoli sprouts may be even better to ward off bladder cancer, says Yuesheng Zhang, MD, PhD, professor of oncology at Roswell Park Cancer Institute, who studied the effect of broccoli sprouts in animals.  His team studied four groups of animals. One group drank a solution known to cause bladder cancer and ate freeze-dried extracts of broccoli sprouts; other groups just ate the broccoli extract or just drank the carcinogen. Another group did nothing, serving as the comparison group.

"Of those who took the carcinogen [only], 96% had a tumor" after 10 months, he says. Of those who drank the carcinogen and also ate the broccoli extract, only 37 developed cancer.

Again, it's the ITCs that are thought to be protective. Broccoli sprouts seem to work, he says, by activating two enzymes important in detoxifying carcinogens.