Smoking kills. Have a cigarette, and you'll die younger. Fail to eat your five a day, you'll die early. Exercise too little, or too much, and – you guessed it – you'll pay the price with your life.
Trying to work out exactly how good, or how bad, anything is has become a total quagmire. What really matters? How dangerous is dangerous? The Norm Chronicles, a new book by journalist Michael Blastland and Professor David Spiegelhalter that has a neat idea which turns all these abstract dangers into a concrete figure.
It centres on this idea: once you hit adulthood (or, being more precise, 22 for a man and 26 for a woman) you can expect to live for around 500,000 more hours – or a million half-hours. Each of those 30 minutes of life is a "microlife".
By working out the average effect of, say, smoking or eating red meat, we can figure out a cost in microlives for different habits. A portion of red meat, for example, costs you a microlife – in the words of Blastland, it's "a 30-minute chip off your stock of adult life".
Smoking is pretty nasty. Puffing on 20 cigarettes a day will cost you 10 microlives each and every day – meaning every 24 hours, you're essentially moving 29 hours closer to death. The extra burger a day we looked at seems a pretty safe indulgence by comparison: eating a burger a day means we'll "age" 24 hours and 30 minutes each day. Not too bad.
On the flipside, there are ways we can buy ourselves extra microlives: spending 20 minutes on any given day exercising vigorously will "earn" you two microlives – an extra hour's breathing. Alas, every extra 40 minutes exercising after that buys only 30 minutes.
There also looks to be a bit of wisdom in the aphorism that a little of what you fancy does you good: the first alcoholic drink of the day buys you an extra microlife – so if you drink fast, you'll come out ahead. But every additional drink after that first tipple chips half a microlife off your stock. Shame. At the time of writing, your correspondent has around 908,000 microlives left. A sobering thought – so it might be time to go and top them up with a quick run. Or, of course, a drink.
