I guess you could think of it this way:
If it's not in the diet of a normal marine animal, your fish aren't probably going to "evolve" quickly enough to live off of it now.
What I've heard is, that bloodworms CAN be fed to saltwater fish. They should not be fed to them on a regular basis, the fats in bloodworms are different than the fats in, let's say, shrimp. You probably wouldn't feed a FW fish shrimp all of the time either...
So I would say, no, stay away from it.