Cancer
Broccoli sprouts may help prevent bladder cancer
By David Liu, Ph.D.
Feb 28, 2008 - 11:34:55 AM

THURSDAY FEB 28, 2008 (Foodconsumer.org) -- Eating broccoli sprouts often may dramatically reduce the risk for development of bladder cancer, according to a study published in the March 1 issue of Cancer Research.

The study showed rats were fed a concentrated extract of freeze dried broccoli sprouts cut the risk for balder cancer by more than half.

Eating cruciferous vegetables like broccoli has been linked with reduced risk fro bladder cancer, according to Yuesheng Zhang, MD, Ph. D., senior author of the study, at Rosewell Park Cancer Institute.

The protective activity of cruciferous vegetables may be due at least in part to isothyiocyanates (ITCs), a group of phytochemicals that have been known to have cancer preventive activities.

"Although this is an animal study, it provides potent evidence that eating vegetables is beneficial in bladder cancer prevention," Zhang said.

In the study, Zhang and colleagues tested the extract of broccoli sprouts in five groups of rats.  Three groups of rats were given drinking water with a chemical known as N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN), which induces bladder cancer.  One group received no extract while other two groups of the exposed rats were given the extract two weeks prior to exposure to the cancer-causing agent.  One group as controls did not receive carcinogen nor extract and the fifth group received only the extract to see the toxicity of the extract.

Two groups of rats that did not receive the carcinogen did not develop any cancer and no toxic effect was observed in the rats that received the extract of broccoli sprouts alone.

In the group receiving the carcinogen alone, 98 percent of the rats developed an average of tow tumors compared to 74 percent in the group receiving a low dose of the extract and 38 percent in the group given a high dose.
    
The broccoli sprouts extract will reduce the number of cancer.  Among the carcinogen-treated rats, those that did not receive the extract got 2 tumors per animal on average compared to 1.39 in those receiving the low dose of the extract and 0.46 in those receiving the high dose.

The extract of broccoli sprouts also reduced the size of tumors.

"The bladder is particularly responsive to this group of natural chemicals," Zhang said. "In our experiments, the broccoli sprout ITCs after oral administration were selectively delivered to the bladder tissues through urinary excretion."    

ITCs are found in mature broccoli, cabbage, kale, collard greens and other vegetables, but broccoli sprouts contains 30 times as much as mature broccoli. ITCs in the extract used in the study were 600 times as much as that found in mature broccoli. The researchers said humans may not need as much to have a protective effect.