Alcohol Concern has thrown down the gauntlet to drinkers: can you manage a month without alcohol? The campaign, Dry January, aims to attract funding through donations, raise awareness of alcohol-related problems and educate people about the health benefits of abstaining from alcohol.

Aside from saving money, Alcohol Concern claims that abstaining will help you lose weight and improve your sleep.

There is no shortage of participants – more than two million people signed up last year, but is there any evidence that Dry January works?

Gram for gram, alcohol contains almost the same amount of calories as pure fat, so abstaining for a month could reduce your weight, assuming you don’t compensate for the lost calories by eating more. Fat accumulates in the liver as a result of drinking. As little as two weeks abstinence can return your liver to good health, reducing the risk of alcohol-related liver disease.

As for improving sleep, there is clear evidence that you will get a better night’s sleep if you abstain from alcohol.

Things have been getting worse

So far so good, but the main ambition of Alcohol Concern is to change the drinking culture in the UK through events such as Dry January. Unfortunately, there is no evidence that Dry January achieves lasting change in consumption or in our beliefs and behaviour in relation to alcohol.

The campaign is premised on the idea of social contagion. If your friends start reducing their alcohol intake you are more likely to adopt the same behaviour.

Most people exhibit denial when asked how much they drink. This is demonstrated by the consistent difference between self-reported consumption of alcohol and total alcohol sales recorded by HM revenue and customs.

There has been an increasing trend in overall consumption of alcohol in the last sixty years. With estimates provided by the alcohol industry suggesting we are consuming 1.4 litres more of alcohol per person than we were in 1975.

As the long term trend in consumption has risen, so has the number of people developing alcohol-related health problems. Since 2009 there has been a 44% increase in those aged 50 and over accessing alcohol treatment.

More generally, alcohol costs every tax payer £120 a year through the one million annual hospital admissions attributable to its use.

If we discovered alcohol today, we would restrict and criminalise its use in the same way we have for drugs such as heroin. Objective examination of harms associated with 20 of the most commonly used legal and illegal drugs ranked alcohol as the most dangerous.

More harm than good?

For people who have developed a dependency on alcohol, abstaining can produce a rebound effect. As a person experiences withdrawal symptoms such as anxiety, sleep disruption and restlessness – paradoxically the very things that many people find alcohol helps them overcome in the short term. This rebound effect could lead to more serious implications for heavy drinkers such as seizures and hallucinations. For this group Dry January may not be the right thing to do as it could cause more harm than good.

The consistent advice from the UK government is to have two dry days a week.

Guidance about alcohol has been difficult to communicate and there is generally confusion about safe levels of consumption. Dry January might add to such confusion giving the message that a month of abstinence does away with the need for regular breaks from drinking.