According to a report from ABC News on January 7th, broccoli contains a compound called glucoraphanin, which is known to have the function of preventing several types of cancer. However, the U.S. Department of Agriculture studied 71 different varieties of broccoli and found that they contained 30 different levels of glucoraphanin, with some varieties containing none at all. Although there are not as many broccoli varieties on the market, the levels of this anti-cancer component also vary. The USDA's research on broccoli aims to cultivate varieties with high levels of anti-cancer components.