A boyfriend with different values - Do we have a chance?

I am dating a boy. He is a good sort of person. He is also about 3 years older than me (I am 17, he will be turning 20 in a month). "Sam" has a lot of excellent qualities about him that I admire and love: we volunteer for the same program (it's where we met), he's a very outgoing person who doesn't hate anyone or anything, he's smart, he listens, he can hold a conversation, and likes to live in the moment. It's that last quality that has caused an issue though.

A big part of living in the moment for Sam is to have fun with his friends. Understandable, right? Well he has fun sometimes by drinking and smoking. Smoking, not so much, but drinking is more frequent. It's a social thing he says, but last night he went by a friend's party for all of 30 minutes to say hi to some people, and he ended up drinking 2 beers and a shot. Sam insists he has a high tolerance for alcohol and that he wasn't even buzzed. This concerns me in more than one way.

My values are very different on the subject. I have made a promise to myself that I won't drink or smoke anything. Call me a prude, but I'm proud of my values. Sam respects them (he would never make me smoke or drink; he also respects my decision not to have sex in high school), but obviously he doesn't follow them.

I'm up in the air about this; I don't want to be a control freak, and I don't mind if he has fun with friends. Yet, it's still weighing on my mind. We haven't been dating long, but we've been close friends for ages. I was always a little worried about it, and it's only grown since we discovered our mutual affection for each other. Can two people with such different values make a relationship? Is there a way I can tell him I'm concerned for him and his health without sounding like a snobby goody two-shoes? Please help me out; I really love this guy and I don't want this to be the end of our relationship!

Thanks everyone :)