Cruciferous veggies may ward off bladder cancer

Substances found in cruciferous vegetables, like broccoli and cauliflower, may help protect people from bladder cancer, a new study shows.

People who consumed the most of these substances, called isothiocyanates (ITCs), had a 29-percent lower risk of the disease than those who consumed the least, Dr. Hua Zhao and colleagues from the University of Texas M.D. Anderson Cancer Center in Houston found.

Studies in animals have found ITCs prevent tumor growth, while epidemiological studies suggest they may lower lung and colon cancer risk, Zhao and his team note in the International Journal of Cancer. They point out that ITCs have detoxifying effects and can enhance the normal development of cells while promoting cell suicide in abnormal cells.
To investigate whether ITCs might protect against bladder cancer, the researchers compared ITC intake for 697 bladder cancer patients and 708 healthy controls. The average age of the subjects in both groups was 63 years old.

On average, the cancer patients consumed fewer ITCs than the healthy individuals. The average number of daily half-cup servings of cruciferous vegetables 1.76 for the healthy individuals and 1.41 for the cancer patients, a statistically significant difference.

High ITC intake reduced cancer risk by 29 percent. The patient factors with the strongest association with reduced risk included past smoking, current heavy smoking, older age and male sex.

The bladder may be particularly susceptible to the anti-cancer effects of ITCs, the researchers note, given that compounds produced by ITC metabolism are excreted through the urine.

"Our data provide strong evidence that consumption of ITCs from cruciferous vegetables protect against bladder cancer," the researchers conclude.

SOURCE: International Journal of Cancer, May 15, 2007.