Researchers at an American university have found that raw broccoli contains small amounts of a cancer-fighting chemical. When one chew broccoli, its cells rupture hence releasing an enzyme that produces chemicals called sulphoraphanes. To simulate chewing the researchers crushed raw broccoli in the laboratory and tested the results. Researchers said that broccoli obtained from common supermarket contains 20 per cent anti-carcinogenic kind of the sulphoraphanes. They also warned that over-heating the green would reduced its cancer-fighting goodness. This research is one of many the studies that will build our knowledge of immune-enhancing foods. This research could lead plant breeders to produce more cancer-fighting foods, offering an natural cure for diseases.