Alcohol Units, a system of units applied to different types and quantities of alcoholic beverages, which focuses on the strength of the alcohol content within each. Alcohol acts on the higher centres of the brain to reduce social inhibitions, anxiety, and the sense of responsibility. This allows the drinker to behave in a more basic way, with less concern for the consequences of his or her actions. Alcohol also diminishes awareness of its own effects so that drinkers do not appreciate the decrease in their judgement and skills.
Alcohol is very easily abused, so it is important to have some standard of consumption. One such system, the unit system, is widely used in the United Kingdom. However, because there is no standardization of the alcoholic content of drinks or of the volume of a standard “drink”, the system is not universally applicable.
The British unit system is based on a standard “drink” containing about 8 g ( oz) of ethyl alcohol (ethanol—that is, pure alcohol). This is called a “unit” of alcohol. One unit of drink equals a half pint of average-strength beer or lager (about 4 per cent), one glass of wine, or one measure of 70-degree proof spirit, such as whisky or gin. There are disparities in terms of alcohol content between different drinks. Cider, for example, tends to be stronger than larger. There is also a certain disparity in terms of alcohol content between different brands of alcohol, such as bottled lagers.
Current recommended safe limits are up to three units per day for men of all ages and up to two units per day for women of all ages. The average heavy drinker, of which there are an estimated 2 million in the United Kingdom, will have a daily intake of at least ten units, or 80 g (3 oz) of ethanol. So someone drinking 80 g of ethanol a day consumes about five pints of beer, five double measures of spirits, or ten glasses of wine. Consistently drinking four or more units a day is not advised.
Drinking one or two units a day is thought to offer some protection against heart disease, though the health benefit from drinking applies only to men over 40. For women, consistently drinking three or more units a day is not advised, and the health benefit from drinking applies only to women who have been through the menopause. Women who are pregnant, or trying to become pregnant, should not drink more than one unit of alcohol, once or twice a week.
In the United States, alcohol intake is measured in “drinks” that are, in general, a little more generous than in the United Kingdom. One drink is taken to be 12 oz (340 ml) of beer, 4 oz (115 ml) of wine, or 1.5 oz (43 ml) of 80-degree proof spirits. Each of these contains roughly 10 g (3y oz) of ethanol. People with a drinking problem who refuse to stop are strongly advised by the US medical authorities to limit their intake to a maximum of two drinks a day.
Table 1 gives average figures for blood-alcohol levels produced by different numbers of units consumed. Table 2 describes the effects of alcohol units on men and women over varying periods of time.
Robert M. Youngson