I thought they’d dropped using units per week as a measure of whether you were drinking too much – the labels on the back of my bottles say “recommend do not regularly exceed: men 3-4 units daily, women 2-3 units daily” (so that’s already above the 21/14 units mentioned in the article – it seems 28/21 is OK or even a bit more if you have a couple of heavy nights a week which is apparently fine).
If I’m reading correctly, that article is saying that when surveyed, people who are actually healthy were drinking more than some arbitrary outdated limits which they reckon means they’re not as healthy as they actually are. I’m also less than convinced that damage due to alcohol is in any way linear with consumption – they might have managed to fit a line to whatever data they generated, but that’s not the same thing at all.
Not that I’m condoning genuine middle class alcohol abuse – there is plenty of that about and I had an aunt who was an alcoholic and died of alcohol related illness. I’m just not convinced that drinking more than 4 units in the evening with a meal in the comfort of your own home is actually that. FWIW my personal average consumption is well below 21 units per week as I often have completely dry weeks, though I do sometimes go well over that.