Sunday, 12 January 2014

Gratuitous advice?

Well, the health lobby aren’t going to be too happy about the results of the poll on eating “five-a-day”. This was another one run jointly with Mark Wadsworth, and achieved an impressive 160 responses. A mere 19% of respondents actually succeeded in eating five a day, while 56% - over half – only managed two or less, and 14% said they didn’t have any at all. There might be some element of making a point in that voting, but even so the conclusion is pretty telling. The original poll results can be seen here – the comments are worth reading.

As I’ve said before, while this isn’t bad advice as such, it is something that was plucked out of the air and has no scientific basis. It tends to be presented as something that is essential to healthy living rather than a nice-to-have ideal, and the consequences of not adhering to it are greatly exaggerated. Also, made-up “rules” of this kind are likely to undermine the credibility of all health messages, however sound their scientific backing. When you were a small child, if you were told not to do something, but given no better reason than “because mummy says so”, you would never have found it very convincing.

I have also reported in the past that a large-scale study found that adhering to this guideline only reduced cancer risk by 2.5%, which is statistically insignificant.


  1. I've had a query here, about how many "units" a normal drink is (pint of beer, large-ish glass of wine).

    I thought it was two (having done a bit of first hand research, i.e. looking at a beer can) but PJH reckoned it was now three.

    Maybe find out and make it clear to your readers, we wouldn't want them being out by a third, would we?

  2. It's 10mg of pure alcohol. Therefore a 500ml can of Carling at 4.0% ABV contains exactly 2 units. A 568ml pint of Abbot Ale at 5.0% contains 2.84 units. A 175ml glass of wine at 13.0% contains 2.28 units. A 700ml bottle of Scotch at 40% contains 28 units, so a theoretical 50ml double Scotch is 2 units.

    It's a reasonable rough approximation that a pint of ordinary-strength (i.e. 4.0% or less) beer contains 2 units, especially bearing in mind that a pub pint is usually at least 5% short.


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