The amount of glucorphanin is not consistent across all cruciferous veggies, so while that may be somewhat true, it is not entirely consistently true. This article seems to indicate that as far as the protective activities reported here are concerned that high glucorphanin is necessary. Broccoli happens to be particularly high in this particular compound, when compared to other similar vegetables. I linked a source to this info in a different comment.
The amount of glucorphanin is not consistent across all cruciferous veggies, so while that may be somewhat true, it is not entirely consistently true. This article seems to indicate that as far as the protective activities reported here are concerned that high glucorphanin is necessary. Broccoli happens to be particularly high in this particular compound, when compared to other similar vegetables. I linked a source to this info in a different comment.