the fact of the matter is that you cannot give your full consent to something for which you dont know the long term consequences. you should not be forced to make up your mind about something for which there is no long term safety data. the fact that there is no long term safety data is not misinformation, and he has no business adopting an attitude of certainty about something which neither he, nor anyone else, can be certain of. it's probably safe, yeah, but why should "probably" be good enough when it's your health and your life that you're gambling with?