April 5, 2006 (Washington) -- A chemical found in broccoli, cabbage, cauliflower, and other cruciferous vegetables can curb the growth of prostate tumors, new research in mice shows.
"Men with prostate cancer should listen to their mothers -- eat your veggies," says researcher Stanley W. Marynowski Jr., MS, of the University of Pittsburgh Cancer Institute.
The research focused on a substance found in cruciferous vegetables called phenethyl-ITC, or PEITC, that is formed when vegetables are either cut or chewed. In lab experiments, PEITC killed off cancer cells through a process known as apoptosis.
"Since we knew PEITC can kill cancer cells, we wanted to see what would happen to established tumors when mice were treated with this compound," Marynowski tells WebMD.
For the study, mice were grafted with human prostate tumors. Then they were fed small amounts of PEITC daily.
The compound slowed the growth of tumors, Marynowski reports. "After 31 days of treatment, the size of the tumors in the treated animals was about half that of the untreated animals."
The researchers now hope to do human studies testing PEITC for prostate cancer prevention in men.
Crunchy Veggies Also Fight Colon Cancer
Tim Oo Khor, PhD, a researcher at Rutgers University in Piscataway, N.J., who is also studying the role of cruciferous vegetables in cancer prevention, says the results are very promising.
"You can significantly decrease tumor volume and effects start to be seen as soon as 16 days after treatment," he tells WebMD.
Khor's study, also presented at the cancer meeting, focused on the role of an antioxidant called sulforaphane in colon cancer prevention. Like PEITC, sulforaphane is released when you chew on broccoli and certain other crunchy vegetables.
For the study, the researchers used mice engineered to be a model for an inherited colon polyp condition seen in people, called familial adenomatous polyposis. People with the condition develop polyps in the colon and are at high risk for the development of colon cancer; left untreated, there's almost a 100% chance cancer will develop.
The mice were fed a diet supplemented with sulforaphane for three weeks.
"The mice did not yet have polyps but would have been expected to develop them within a few weeks," Khor tells WebMD. "We wanted to see if we could interfere with that. And we did," he says.
Though the mice did develop some polyps, there were much fewer than expected -- about half as many, Khor says. Also, the polyps were much smaller than expected.
"The findings suggest sulforaphane may have an important role in the protection against cancer in patients with familial adenomatous polyposis," he says.