Because the epidemiologic studies indicate that you would need to eat 1.5 pounds of minimally cooked (or raw) broccoli (or other brassica vegetables) every day for years to get the full benefit.

What about broccoli sprouts?

These could be a better choice, but you would have to eat 4-8 ounces daily, which is an expensive proposition. On top of that, the public health authorities are now saying that there is no way to effectively ensure that sprouts will be free of bacterial contamination, even if all the proper growing procedures are followed.

The bottom line

For maximun benefits, always consume a serving of brassica vegetables (for the myrosinase) in combination with the broccoli seed extract, Rountree says. In effect, this is like consuming Beneforté’s "super" broccoli, which effectively triples the amount of the active sulforaphane that gets into the bloodstream. Finally, stay tuned, he says—lots more broccoli data to come.