LIVING to a ripe old age owes a fair amount to luck, but if science can tell us anything about health, it is that our judgement matters, too. The way we live our lives and the way we treat our bodies can make a huge difference to our chances of having a long and healthy life.
This is the basic message encoded in the generic health targets that we all carry in our heads: five pieces of fruit or veg a day, 8 hours of sleep, 10,000 steps, 2000 calories and so on.
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Yet on closer inspection, many of the best-known nuggets of health advice owe more to marketing and folklore than they do to science. The 10,000 steps per day that so many people aim to take seem to have been largely plucked from nowhere. Even dentists can鈥檛 tell you why they recommend brushing specifically for 2 minutes, twice a day, as our feature on page 38 reveals.
To make matters worse, even advice that stems from decades of research comes from epidemiological studies, which follow large numbers of people over many years. Translating this kind of data into one-size-fits-all advice is notoriously difficult for the simple reason that we aren鈥檛 all the same.
鈥淢any nuggets of health advice owe more to marketing and folklore than they do to science鈥�
The number of hours you need to sleep for can vary by 7 hours , for example. Then there is the ideal number of steps, which differs depending on whether you are hiking up the side of a mountain or ambling around a shopping mall. And since science鈥檚 work is never done, even solid health advice can, and does, change.
With this much complexity, it is tempting to just ditch living by numbers. Yet targets do have a part to play in health education. Even though fewer than a third of UK adults actually manage to consume five portions of fruit and vegetables a day, the average child at primary school can recite the guideline, so at least has internalised the message that eating plants is good for you.
And of course, given that our brains are wired to choose instant gratification over a vague promise of better long-term health, even imperfect advice is better than none.
