Oct. 28, 2003 -- You might already have some of the newest cancer-fighting drugs. But you'll find them in your kitchen, not in your medicine cabinet.
New studies show anticancer effects in ginger, tea made from a Chinese herb called barbed skullcap, and the more traditional green tea. The reports were presented this week's Frontiers in Cancer Prevention Research meeting, sponsored by the American Association for Cancer Research.
Ginger's intense flavor comes from its main ingredient -- a chemical called -gingerol. And that's not all this chemical does, says Ann Bode, PhD, assistant director of the Hormel Institute at the University of Minnesota, Minneapolis-St. Paul.
Bode gave a small dose of gingerol to 20 mice three times a week. The mice -- which lack an immune system -- ate the ginger ingredient before and after getting injections of human colon tumor cells.
"Mice that received gingerol had a very marked inhibition of human cancer growth," Bode said at a news conference.
How impressive are the results? Well, it's only mice. But the University of Minnesota has applied for a patent on the use of -gingerol as an anticancer agent. It has already licensed the technology to Pediatric Pharmaceuticals of Iselin, N.J.
Of course, all fresh ginger contains gingerol. How much would you have to eat to get an anticancer effect? Not much -- but it depends on the freshness of the ginger and the kind of ginger you get.
"The ginger component we used is a primary component of ginger root," Bode tells WebMD. "There can be a half gram of it per gram of ginger root, but this depends on how the ginger is processed and how it is grown. We really don't know how much ginger root you would have to eat to get the same effect we saw in mice. However, in the popular literature, people have consumed 2-8 grams twice a day with no toxic effect. I am not saying I recommend that, but depending on their culture a lot of people eat a lot of ginger."
Barbed skullcap is the Chinese medicinal herb ban zhi lian. Its scientific name is Scutellaria barbata. Tea made from the herb has been used for a variety of purposes -- including treatment of liver, lung, and rectal cancer.
Brian Wong, PhD, of Union College in Lincoln, Neb., tried giving it to a strain of mice bred to develop prostate cancer. Normally, these mice quickly develop fatal prostate tumors. Those who received barbed skullcap had much slower tumor growth.
"We hope to find the same benefits against prostate cancer in human models," Wong says in a news release.
The herb is brewed into a dark tea. It's very potent, Wong says, and only a small cupful provides a full dose. However, he warns against drinking lots of the tea in an effort to prevent cancer.
"I drink it because I know on the molecular level it is blocking carcinogens," Wong says. "But I don't drink it daily. We need to work out the liver toxicity of the extract. Too much is not good."
Several researchers presented new research into the anticancer effects of green tea.
Nurulain Zaveri, PhD, of SRI International in Menlo Park, Calif., reported on the green tea extract known as EGCG (epigallocatechin-3-gallate). Though this extract is thought to have anticancer properties, it's not easily absorbed by the body. One would have to drink seven or eight cups of green tea a day to get an effective dose of EGCG.
Zaveri's team developed a form of EGCG that's more easily absorbed. In the test tube, it inhibits a breast cancer growth factor.
Iman Hakim, MD, PhD, of the Arizona Cancer Center, led a study in which smokers drank four cups a day of green or black tea. Decaffeinated green tea -- but not black tea -- cut down on one kind of DNA damage seen in smokers.
Jia-Sheng Wang, MD, PhD, of Texas Tech University, led studies of the effects of a green tea extract on people at high risk of liver cancer. Study participants received green tea polyphenols for three months. At the end of the study, they had lower levels of a chemical marker for liver cancer risk.
SOURCES: Frontiers in Cancer Prevention Research conference, American Association for Cancer Research, Phoenix, Oct. 26-30, 2003. News release, AACR. News release, University of Minnesota. News conference, AACR.