What are the recommended safe limits of alcohol?
- Men should drink no more than 21 units of alcohol per week, no more than four units in any one day, and have at least two alcohol-free days a week.
- Women should drink no more than 14 units of alcohol per week, no more than three units in any one day, and have at least two alcohol-free days a week.
- Pregnant women. Advice from the Department of Health states that … “pregnant women or women trying to conceive should not drink alcohol at all. If they do choose to drink, to minimise the risk to the baby, they should not drink more than 1-2 units of alcohol once or twice a week and should not get drunk”.
Where do these recommendations come from?
- The Department of Health recommends that men should not regularly drink more than 3-4 units of alcohol a day and women should not regularly drink more than 2-3 units a day. ‘Regularly’ means drinking every day or most days of the week. And if you do drink more heavily than this on any day, allow 48 alcohol-free hours afterwards to let your body recover.
- The Royal College of Physicians (RCP) advises no more than 21 units per week for men and 14 units per week for women. But also, have 2-3 alcohol-free days a week to allow the liver time to recover after drinking anything but the smallest amount of alcohol. A quote from the RCP… “in addition to quantity, safe alcohol limits must also take into account frequency. There is an increased risk of liver disease for those who drink daily or near daily compared with those who drink periodically or intermittently.”
- The House of Commons Science and Technology Committee advise that people should have at least two alcohol-free days a week.
- Some would argue that the upper limits of the recommendations are too high. For example, one study found that more than two units a day for men and more than one unit a day for women significantly increases the risk of developing certain cancers.
Why these recommendations?
Your liver processes alcohol. It can only cope with so much at a time. Drinking more alcohol than the liver can cope with can damage liver cells and produce toxic by-product chemicals.
The more you drink, and especially above the recommended limits, the greater the risk of developing serious problems such as: liver disease (cirrhosis or hepatitis); cancer; gut and pancreas disorders; depression; anxiety; sexual difficulties; muscle and heart muscle disease; high blood pressure; damage to nervous tissue; serious accidents; obesity (alcohol is calorie-rich). See separate leaflet called Alcohol and sensible drinking for more details.
Alcohol gets to a baby through the placenta if a pregnant woman drinks alcohol. A baby cannot process alcohol very well. So, any alcohol in your baby stays in their body much longer than in you. This is known to be a risk for causing serious problems such as: a low birth weight; learning, behavioural, and thinking (cognitive) problems; defects of the heart and other organs; abnormal facial features. When these problems are severe, the condition is called fetal alcohol syndrome.
However, there has been debate over the years as to whether small amounts of alcohol are safe to drink during pregnancy. Also, if there is a time of pregnancy when alcohol is most likely to cause harm. But, recent research supports the advice of not drinking any alcohol whilst pregnant.
For example, a study by Feldman et all (cited below) looked at the relationship between drinking alcohol during pregnancy and it causing facial defects in the baby. This study showed that the more alcohol a woman drank, the more likely there was to be a facial defect in the baby. BUT, there was no safe amount of alcohol to drink during pregnancy, as there was still some risk with small amounts of alcohol. The study also found that drinking alcohol has risks throughout pregnancy, but it may be most likely to cause facial defects during weeks 6-12 of pregnancy. The authors of the study concluded that … “Women should continue to be advised to abstain from alcohol consumption from conception throughout pregnancy.”
What is a unit of alcohol?
One unit of alcohol is 10 ml (1 cl) by volume, or 8 g by weight, of pure alcohol. For example:
- One unit of alcohol is about equal to:
- half a pint of ordinary strength beer, lager or cider (3-4% alcohol by volume); or
- a small pub measure (25 ml) of spirits (40% alcohol by volume); or
- a standard pub measure (50 ml) of fortified wine such as sherry or port (20% alcohol by volume).
- There are one and a half units of alcohol in:
- a small glass (125 ml) of ordinary strength wine (12% alcohol by volume); or
- a standard pub measure (35 ml) of spirits (40% alcohol by volume).
But remember, many wines and beers are stronger than the more traditional ordinary strengths. A more accurate way of calculating units is as follows: the percentage alcohol by volume (% abv) of a drink equals the number of units in one litre of that drink. For example:
- Strong beer at 6% abv has six units in one litre. If you drink half a litre (500 ml) – just under a pint – then you have had three units.
- Wine at 14% abv has 14 units in one litre. If you drink a quarter of a litre (250 ml) – two small glasses – then you have had three and a half units.
Some other examples
Three pints of beer, three times per week, is at least 18-20 units per week. That is nearly the upper weekly safe limit for a man. However, each drinking session of three pints is at least six units, which is more than the safe limit advised for any one day. Another example: a 750 ml bottle of 12% wine contains nine units. If you drink two bottles of 12% wine over a week, that is 18 units. This is above the upper safe limit for a woman.
Isn’t alcohol good for you?
For men aged over 40 and for women past the menopause, it is thought that drinking a small amount of alcohol helps to protect against heart disease and stroke. The exact amount is not clear, but it is a small amount. So, do not exceed the recommended amount of alcohol as described above in a mistaken belief that it may be good for the heart.
References and Disclaimer | Provide feedback
- Alcohol Advice, Dept of Health, 14 February 2012
- Alcohol – problem drinking, Prodigy (September 2010)
- Alcohol Guidelines, House of Commons Science and Technology Committee – Eleventh Report (2011)
- The evidence base for alcohol guidelines, Royal College of Physicians (2011)
- Schutze M, Boeing H, Pischon T, et al; Alcohol attributable burden of incidence of cancer in eight European countries BMJ. 2011 Apr 7;342:d1584. doi: 10.1136/bmj.d1584. [abstract]
- Feldman HS, Jones KL, Lindsay S, et al; Prenatal alcohol exposure patterns and alcohol-related birth defects and growth Alcohol Clin Exp Res. 2012 Apr;36(4):670-6. doi: [abstract]