Thanks for this. I'm a using alcoholic - have done rehab, AA, all my steps, a year teetotal, and now drink 'normally'. It's irrational of me, but it's what I wanted to achieve. Still have to watch my intake, obviously, and don't drink regularly. I've had loads of liver function tests, scans, the lot - and it's fine, thank goodness.
The human body has four enzymes that metabolise alcohol. These enzymes can cause organ damage if they go out of balance. Variable proportions of the enzymes are available to each person, according to their genes. Some people have very few of these enzymes (common in South Asians, for instance) while some have plenty of all four in a good balance (common in Germanic people). This is probably why ancient Asians sanitised their drinking water by brewing tea, while Europeans brewed beer instead.
There must be some test to establish your genetic alcohol tolerance but, in any case, you'll be more susceptible to getting ugly drunk and bad hangovers if you aren't built for booze. The obvious takeaway from this is STILL that it's best not to drink alcohol, or to drink very sparingly, but it's interesting that outcomes are not uniform because people are different.