Last time I uploaded the new UK Drinking Guidelines that were issued in January 2016. Today I just want to clarify some of the less obvious statements in the Guidelines.
The amount of alcohol consumed is expressed in ‘units’ but the definition of a unit isn’t stated. A unit is a measure of the alcohol content of a drink, not of the amount of the drink itself. One unit is 10ml of pure alcohol (in the UK, it varies elsewhere).
For example, a large glass of wine, which is 175ml, containing wine of strength 13% abv (alcohol by volume), contains 175 * 13% = 22.75ml of pure alcohol, the rest being mostly water. This is therefore a bit over two units, 2.275 units to be exact. Drink one of those on six days of a week (plus one dry day) and there are almost your 14 units a week, the recommended maximum. If the wine is 13.5% abv or stronger, this will take you over the limit!
Regarding beer, this is usually between 4% abv and 6% abv. A pint at 5% contains 2.84 units of alcohol, so one pint a day for five days is your lot for the week.
You drink spirits? Most are 40% abv and a single measure (in England) is either 25ml or 35ml – landlords have flexibility here. These contain, respectively, exactly one unit and 1.4 units. So the weekly limit is 14 measures of 25ml, or 10 measures of 35 ml – or half as many doubles. To avoid any misunderstanding, diluting your short with water, tonic, soda or cocktail ingredients makes absolutely no difference – the amount of alcohol is unchanged.
The main difference between the new Guidelines and the previous ones is that the advisory limit for men was previously 21 units per week, which has now been brought into line with women at 14 units. The reason for this is that the emphasis has moved from liver damage (fattening of the liver, cirrhosis, or even liver cancer) to cancers of all sorts. The new Guidelines state that the risk of cancers of the mouth, throat and breast in particular increases with any amount you drink on a regular basis. In other words, there is no u-shaped risk curve for cancer. One glass of red wine a day is still widely thought to offer some protection against heart attacks, but there is no such benefit regarding cancer.
In future blogs we will look into these relationships – and the medical evidence for believing in them – a bit more closely. By how much do the various risks increase with alcohol intake, does that make them become significant risks, and how certain are medics about the strength of these relationships?