You might think that a unit of alcohol is an international standard, but in fact it varies from country to country, with many places not defining a standard at all. A new study by Agnieszka Kalinowski and Keith Humphreys, just published in Addiction magazine, sets out to wrangle these figures, along with the recommendations in each country for daily and weekly consumption.
Of 75 countries studied, only 37 had a standard drink definition, and these are seen in the table below. One notable country is Japan, which has no standard drink size, but does have daily recommendations. The researchers gathered the figures from both official sources, from WHO data, and from internet searches leading to official government data on the subject. When this failed, the authors contacted the governments directly.
For the chart shown here, I have picked the highest number when the official figure is not exact. For example, Portugal defines a drink as 10-12ml of alcohol, so I counted it as 12. Also, I used the original measures, in milliliters, to keep the chart clear. Converting into fractions of an ounce would make it impossible to read. For reference, one ounce equals 30ml. And remember, that's for pure ethanol. A shot of whisky is only around 40% alcohol, for example.
The most common size is 10ml, with most other countries defining a drink as containing between 10 and 14ml of ethanol. Austria is way out ahead of the rest, doubling the norm at 20ml. 8ml is the lowest official size for a drink.
More variation comes in the daily recommended amounts. Chile and the United States tie for the most generous allowance, at 56ml per day for men, but both have less generous weekly limits (196). Some countries have fairly low daily recommendations, but comparatively large weekly allowances. And as you can see from the second chart, some countries maintain different recommendations for men and women.
But the measurements aren't the whole story. The figures are affected by the kind of drink most popular in the country. Beer and wine in the U.K., beer in Germany, and so on. Also, the U.K. still serves some drinks in imperial measures (beer comes in a pint), and some in metric (spirits are measured in ml), and the U.S uses ounces and pints. These, too, affect the figures:
Indeed, in those countries where the most widely consumed drinks contain an amount of ethanol other than 10 g it may be more sensible for public health officials to match the national standard drink definition to prevalent drinking practices rather than attempt to teach the public an alien system (e.g. ‘The drink you consider standard shall henceforth be known as 1.6 standard drinks instead’).
Therefore, a standard drink could be pretty large, but paired with a smaller recommendation for consumption.
Clearly not all of these recommendations are correct, but this study does show just how hard it is to nail down hard figures for a national health policy, let alone an international one. But if you're worried about your liver, you should probably move to Poland or Vietnam, both of which have the highest weekly limit (280ml) of all countries in the study.