So the TLDR is if youre >= 65, decrease alcohol consumption. If you're <65 optimal range is 15-20 units per week, better if it's even consumption per day.

"One unit of alcohol is about equal to: half a pint of ordinary strength beer, lager or cider (3-4% alcohol by volume); or. a small pub measure (25 ml) of spirits (40% alcohol by volume); or. a standard pub measure (50 ml) of fortified wine such as sherry or port (20% alcohol by volume)"[1]

So in short: have 2 weak pints of beer xor 1 strong pint of beer xor 150ml of 13% wine.

Can someone confirm,refute this understanding of the text.

[1]:http://www.patient.co.uk/health/Recommended-Safe-Limits-of-A...