Contemplating Our Microlives

I'm not a big fan of the optimization mindset when it comes to long term health and longevity. Like all forms of optimization, it makes for a great hobby - with the potential to turn into a massive sink of time and money if you head on all the way down the rabbit hole. Importantly, however, and unlike optimization hobbies that involve cars, games, and other easily measured items, you will never really know how well you are doing when it comes to your own life expectancy. It's extremely easy to get the 80/20 result: practice calorie restriction and exercise regularly. But beyond that, there's no real way to tell whether any of your more esoteric practices are helping, hindering, or doing more or less nothing. There is no meaningful scorecard for future remaining life expectancy that you can measure and check your optimization efforts against.

This may well change over the next ten years, but for now it is what it is. By all means make health your hobby - it beats some of the other options in terms of general utility - but don't for one moment imagine that you actually know how well you're doing past the 80/20 point. And if you're not practicing calorie restriction, then it doesn't much matter what else you're doing because you haven't even captured all of the easy 80%.

Anyway, that all said, here is an interesting article that looks at measuring risk and life expectancy at the small scale - which is often a prelude to optimization, given human nature.

Many risks we take don't kill you straight away: think of all the lifestyle frailties we get warned about, such as smoking, drinking, eating badly, not exercising and so on. The microlife aims to make all these chronic risks comparable by showing how much life we lose on average when we're exposed to them: a microlife is 30 minutes off your life expectancy

Life expectancy for a man aged 22 in the UK is currently about 79 years, which is an extra 57 years, or 20,800 days, or 500,000 hours, or 1 million half hours. So, a young man of 22 typically has 1,000,000 half-hours (57 years) ahead of him, the same as a 26 year-old woman. We define a microlife as a chronic risk that shortens life on average by just one of the million half hours that they have left.

Here are some things that would, on average, cost a 30-year-old man 1 microlife:

  • Smoking 2 cigarettes

  • Drinking 7 units of alcohol (eg 2 pints of strong beer)

  • Each day of being 5 Kg overweight
  • A chest X-ray will set a middle-aged person back around 2 microlives, while a whole body CT-scan would weigh in at around 180 microlives.

    This falls under the general heading of "fun with population-wide statistical measures of mortality," but you should find it food for thought, even if not of immediate application. On that note, an interesting speculative calculation to run, or at least build a framework for, would be a guesstimation of the benefit in microlives gained per dollar donated to the SENS Foundation.


    At their best these 'biological age quizzes' are well intentioned, but somewhat misguided, educational tools. At their worst, they are propaganda tools to promote some agenda.

    Posted by: JohnD60 at January 18th, 2012 9:59 PM

    This microlives article doesn't take the right baseline into account: Their 22yo male with 79 years of life expectancy is an average Brit, so he already smokes 2 cigs, drinks to pints and is 5kg overweight (at least).

    Posted by: Hervé Musseau at January 19th, 2012 4:19 AM

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