By Michelle Roberts
Health Reporter, BBC News
The units in a glass of wine can range from 1.5 to over 3
Daily limits on alcohol consumption are meaningless and potentially harmful, experts have warned.
The government says men should drink no more than three to four units per day and women no more than two to three.
Liver specialist Dr Nick Sheron, of the Alcohol Health Alliance UK, says these limits were devised by civil servants with "no good evidence" for doing so.
He says the advice runs the risk of people taking it to mean that it is safe to drink alcohol every day.
They were turned into daily limits by a community of civil servants and the reasoning behind it is shrouded in mystery
Dr Sheron, vice chair of the Alcohol Health Alliance UK
Dr Sheron's comments follow a report by MPs on the Public Accounts Committee which suggested public confusion about safe drinking levels was fuelling problem drinking.
Dr Sheron says we should go back to using the old weekly limits, which are based on sound research.
The 1987 sensible drinking limits, which set the bar at 21 units per week for men and 14 units per week for women, remained in place until 1995.
It was then that the government decided to switch the limits from weekly to daily in a bid to curb binge drinking and emphasise the harms of saving up a week's limit to blow in one or two sessions at the weekend - a decision it stands by today.
But Dr Sheron says this was a mistake: "They were turned into daily limits by a community of civil servants and the reasoning behind it is shrouded in mystery and is not largely supported by experts.
"The weekly limits were based on robust studies and were set at a level at which alcohol harms outweigh any putative benefit."
Some studies show that alcohol, in moderation, can reduce the risk of heart disease.
In terms of damage to the liver, the risk begins when regular weekly consumption exceeds about 30 units, said Dr Sheron.
But for other conditions, like cancer, the risk starts at zero and goes up proportionately with the amount of alcohol is consumed.
Although the daily recommendations originally included the important caution to have some alcohol-free days, Dr Sheron this message has got lost.
The advice now warns against regularly drinking over the daily limit and says drinkers should also "take a break for 48 hours after a heavy session to let your body recover."
One unit of alcohol is 8g (or 10ml) of pure alcohol
A half pint of normal strength (4%) beer, lager or cider is 1 unit of alcohol, as is half a standard 175ml glass of 12% wine or one 25ml measure of spirit
Drinking over 8 units for men or over 6 units for women is seen as binge drinking
Dr Sheron said that by setting a daily limit, people might take this to mean they could drink every day.
Dr Rachel Seabrook, research manager at the Institute of Alcohol Studies, agrees.
"The Royal Colleges' recommendation for two days of abstinence a week has quietly disappeared. It was probably dropped to keep the message simple. But that is not a good move.
"And we are quite concerned about the use of 'daily' in the message. It implies that you can drink on every day.
"There should be an explicit warning against this."
A Department of Health spokesman defended the current recommendations saying: "Advice on limits is based on scientific evidence from studies in populations in this country and worldwide about long-term health harms for broadly average, healthy adults.
"The scientific evidence base was examined by an inter-departmental working group in 1995. This has been kept under review since then.
"There are a number of public health campaigns to help people understand government guidelines around drinking alcohol.
"Ongoing and future campaigns will also help people to live more healthily."
In Britain in 2007, 69% of people reported that they had heard of the government guidelines on alcohol consumption. Of these people, 40% said that they did not know what the recommendations were.
Although binges are dangerous and can cause harm - largely through accidents caused by reckless behaviour - in terms of long-term health risks, it is the average amounts consumed over the weeks, months and years that count.
A person who regularly drinks 50g of alcohol a day - around 6 units or three pints of normal strength (4%) beer - has nearly double the risk of stroke, high blood pressure and pancreatitis as someone who abstains.
In a snapshot survey for England in 2006, 12% of men and 7% of women reported drinking alcohol every day during the previous week.
In the same year, 23% of men and 15% of women reported binge drinking.