The problem is there are more ignorant people in the world than there are educated people, and that goes for any specific thing. In other words, how much do you know about diamonds? Mechanical failures in cars? The political climate in Pakistan? Etc., etc. So what you do is listen to the experts in those areas that you don't know much about. Lucky us, the experts we get to listen to have a barry bonds book to sell, or someone with some other vested interest.
Ok, so these tv shows, reporters, etc., need to sell something, their show, airtime, their article, their book, whatever. What is going to sell more to more people, the man whose arms exploded, or sensible usage of hormonal chemicals combined with resistance training and their benefits and possible side effects?
If you want to devote some time to the subject, with a little bit of determination, the average person could probably somewhat educate themselves on the subject over a period of 6 months or so. However, this 'education' is still a little like religion. There are some things you take on faith because there really aren't any studies that look into doing what we do, and the few out there that do, aren't long term. So guys like you and me tend to see what we want to see. Women like her tend to see what she wants to see.
Obviously education will tend to temper her views, however if she really does think they are dangerous, she will continue to think there are risks. And like it or not, there are risks. But there are risks associated with driving a car, and yet you probably do this on a regular basis.
If she is this upset over your usage, at least one positive is that she shows she cares about you and your safety.