As somebody who used to be a functional alcoholic, here’s how I like to put it to people simply: The brain doesn’t operate independently of the body. If you’re consuming something that negatively affects systems across the entire body, even if the short term effects on the brain aren’t as severe as those other parts, it will still end up affected. If you’re a drinker and you’re noticing long-term effects in your brain, you’ve likely by that point already done much more severe damage to your other internal organs. That damage affects your brain’s ability to take care of itself, among other things. Let’s just say it’s best to not let things get to that point.