It was once a favourite theory of optimistic drunkards that a suitably ‘moderate’ level of alcohol consumption provided covert health benefits. The mechanism was always a little obscure. But it was a fairly sure thing that reds — or was it all booze? — by virtue of some enzyme or vitamin or whatever, and judiciously drunk in something between homeopathic and industrial quantities, protected against heart attack — or was it ischaemic stroke… or memory loss? This, at any rate, was the glass-half-full defence of moderate drinking.