To those who are adamant it is wrong, let me ask you this:
At what age do you think it's acceptable then?
At what age did YOU drink?
How do you expect to teach your child to deal with alcohol if they are not allowed to touch it until they're 18?
I'm not suggesting we let kids get pissed. But it's totally unrealistic to expect them not to drink. Half of teenagers have drunk by the time they are 15.
And in that context it's better to introduce it openly in a controlled manner. So your child can talk to you about what the effects are, so they can be honest about what they are doing. Than ban it and they just hide it.
I've a teenage daughter and I've found that it's way better to give her the information and let her make her own mind up on things than "forbid" things.
As for smoking, actually I'm incredibly grateful to my late granddad who used to smoke himself. I was about 9 when I was very curious about this strange smoking thing he was doing. He gave me half his cigarette. I've not touched one since.
I can hear the screams of child abuse now from some but for me that half a fag has stayed in my mind for 30 years and I haven't touched one since. Even when all my mates at school smoked, I walked off.
Ditto with drinking. Once you can send your mum to the off license at 14. Once there's nothing to hide, it's not cool. It's just a waste of money. I didn't drink much as a child in the end and I barely drink now.