I know this thread is over a year old but I expect this issue pops up all the time, feeling compelled to drink at social or work functions.
I don't have a problem with alcohol. I used to drink socially and enjoyed it, but in the past few months noticed that if I even had one drink my stomach would hurt the next day. I went gluten-free in the past few months to help my stomach also and it *has* helped.
So now I don't drink at all. If anyone asks I tell them the truth, it'll bother my stomach the next day. No one pressures me but I wouldn't care if they did.
Just say no, it really is fine even if it's "Beer Friday", even if it's the company culture to go out and drink: It's fine not to. It is absolutely my firm's culture to drink at social events. The firm provides an open bar at every event. They pay for Uber/Lyft if people are not safe to drive home. That's how embedded alcohol is.
But: there are always those (and now me) who don't drink. It's a non-issue. No one cares. Just say no and don't worry about it.