Boxing good or bad for you??

I am interested in studying western boxing, and I have found a place to take it. However, I have talked to several docters, and almost all say it is going to give me brain damage. I think there is a misconception between training boxing and holyfield and tyson hammering each other to a pulp. I am wondering if the training for boxing includes taking lots of head shots, how long do you train before you start to get hit a lot, and how dangerous is amateur boxing? Amatuer boxing has headgear and it’s for points, you don’t have to kill the other guy, but still, it looks like most amateur boxers are trying to knock you out with every shot from what I have seen. Also, how effective is the headgear worn by amateur boxers? If I do take boxing, I will probably not be competing as my parents are very much against it (not against full contact sparring, though, go figure). If I just train and do little or no competing, am I still going to get a whole lot of brain damage?
thanks,
adam