Broccoli chemical stops cancer

Macerated raw broccoli turns out to contain small amounts of a potent chemical that inhibits the oxidizing enzymes that damage DNA and potentially cause cancer.

Nathan Matusheski, a researcher at the University of Illinois at Urbana-Champaign, crushed raw broccoli in the lab to mimic chewing, and tested the resulting mush. He found that when a person chews broccoli, its cells rupture and release an enzyme that produces a class of chemicals called sulphoraphanes.

In common supermarket broccoli, 20 percent of the sulphoraphanes are the anti-carcinogenic kind, which have an extra sulphur atom in each molecule. The rest lacks this crucial extra sulphur and has no cancer-fighting capability. But when he tested broccoli that had been heated to 60 degrees Celsius, Matusheski found the relative levels were reversed, favoring the anti-cancer compound.

A protein in broccoli called ESP plays a role in pushing the balance towards the sulphur-poor sulphoraphane. Matusheski confirmed that heating the broccoli destroys ESP, tipping the balance in favor of the beneficial sulphoraphane. However, cooking broccoli conventionally does not help, as the enzyme that produces sulphoraphanes in the first placed is also destroyed.

"This is one of many studies that will build our knowledge" of immune-enhancing foods, says Sara Risch, a food technology adviser with the Chicago-based food science consultancy Science by Design, in a recent interview with the Washington Post. "This research identifies something that could be taken to the plant breeders," she said.

One way to ensure high levels of the beneficial compound may be to eliminate the genes that code for the ESP protein. This could be done by making hybrids with wild strains, said Matusheski, who prefers this approach on an ethical basis, when compared to another method that would use gene silencing, another technological process.

These compounds may be protective against several types of cancer, including breast, colon, and bladder cancers.

In an unrelated story, nutritionist William G. Helferich also of the University of Illinois at Urbana-Champaign and his colleagues were trying to find out why Polish women who have moved to the United States are far more likely to develop breast cancer than family members remaining in the Old Country. One distinguishing factor turned out to be consumption of cabbage. European Poles eat far more.

"Though it's very unlikely you'd get those higher concentrations in the blood from eating brassicas," Helferich said in a recent interview with Science Newst, and suspects that "it is realistic you could get the anti-estrogenic doses." His group's findings appear in the October 2000 Journal of Agricultural and Food Chemistry.

Because of their cancer-preventitive components, broccoli was genetically modified in 2000, in the UK by food scientists to reduce the risk of cancer. The vegetable was a cross between ordinary broccoli and a wild Sicilian relative. It tastes the same as the standard variety.

According to BBC News, scientists hoped the vegetable, containing 100 times more sulphoraphanes. could help to cut the number of cases of colon cancer, one of the biggest cancer killers in the world.

Plant biologist Dr. Mithen,in a recent interview with BBC News, said the anti-cancer properties of broccoli not only helped prevent bowel cancer, but may also slow down already developing cancers.

Dr Mithen also said: "It's fairly well acknowledged that a third of all cancers are probably caused by bad diet. It would really be quite something if this new broccoli contributed to lowering colon cancer rates."

The Illinois scientists have partially purified anti-estrogenic constituents of the extracts and distributed portions to other researchers who study brassicas' cancer-fighting compounds. It appears these newly isolated anti-estrogenic agents "are novel," Helferich told Science News.

Another vegetable, cabbage, also belongs to the Brassica family. A host of recent studies has shown that brassicas, which include broccoli, cauliflower, brussel sprouts, and mustard, possess cancer-fighting compounds.

Helferich wondered whether fermenting such veggies, as in making sauerkraut, would create new anticancer agents. Others might arise when stomach juices acidify vegetable compounds. Specifically, the researchers wondered whether the brassicas give rise to estrogen blockers.

Despite major advances in science, it has been proven again and again that cancer can most easily be prevented by a proper diet.