GRAPES, WINE MAY INHIBIT CANCER, STUDY SAYS.

Byline: Jane E. Brody The New York Times

Grapes and red wine, already heralded for their potential to prevent heart disease, may also harbor a potent cancer inhibitor, according to a study being published today in the journal Science.

Researchers at the University of Illinois showed in preliminary laboratory and animal studies that the substance, resveratrol, which is prominent in the skin of grapes, may interfere with the development of cancer on several levels: by blocking the action of carcinogens, inhibiting the initiation and promotion of tumors, and causing precancerous cells to revert to normal.

But it is not yet known whether eating grapes or drinking red wine results in biologically useful levels of resveratrol in a person's blood. Researchers have not demonstrated that resveratrol, which is soluble in alcohol but not water, is absorbed by humans who consume it through foods or wine.

Resveratrol, a relatively simple chemical substance that could easily be made synthetically to produce a supplement, was found in previous laboratory studies to lower blood levels of cholesterol, block the formation of the kind of cholesterol that clogs arteries and reduce the tendency of the blood to form clots. But its usefulness as a protector of the human heart has not yet been established.

Although the skin of grapes is the leading known food source of resveratrol (pronounced rez-VER-a-trawl), it is also found in peanuts and in lilies and in some traditional Asian medicines made from roots.

The University of Illinois researchers originally isolated resveratrol from a crude extract of the roots of a Peruvian tree, one of thousands of plant extracts they are screening for cancer-fighting potential under a grant from the National Cancer Institute.

Dr. John Pezzuto, who oversees the research at the university's College of Pharmacy, said that resveratrol was a chemical defense agent that the plant produced in response to environmental stress, especially fungal infections.

Specialists in cancer prevention said the finding that resveratrol might inhibit cancer development suggested one more reason that eating lots of fruits and vegetables was associated with a reduced risk of cancer.

Dr. Peter Greenwald, director of the division of cancer prevention and control at the National Cancer Institute, said, ``More than 150 studies have clearly shown that groups of people who eat plenty of fruits and vegetables get less cancer at a number of cancer sites.''

In addition to vitamins, minerals and fiber, many substances have been found in all kinds of plant foods that are believed to be useful in preventing the development of cancer.

Among them are antioxidants that block gene damage, enzyme-inducing substances that detoxify carcinogens, sterols that stop the uncontrolled growth of cells and genistein, found in soy-based foods, which interferes with the blood supply to tumors.

In the Illinois studies, resveratrol was initially singled out because it was shown to have anti-inflammatory activity. Anti-inflammatory compounds like aspirin and indomethacin can inhibit tumor promotion and have been linked to a reduced risk of colorectal cancer in humans.

Further studies of resveratrol in cultures of laboratory cells showed that it could block the action of a known gene-damaging and cancer-causing agent and that it could stimulate cells to produce enzymes that detoxify carcinogens. One more laboratory study showed that resveratrol could make human leukemia cells stop proliferating.