The effect of Dry January: What happens to your body when you give up alcohol for one month?

Written by: Professor Kevin Peter Moore
Published:
Edited by: Nicholas Howley

If you drink more than 14 units of alcohol a week – that’s about 6 pints of beer or 14 low-strength glasses of wine – then you’re drinking too much alcohol, according to UK Chief Medical Officers.

This is the same whether you’re a man or a woman. Drinking guidelines used to specify different amounts for men and women, but they’ve recently been revised down.

Why is this? There’s increasing evidence that drinking too much alcohol causes a wider range of health issues than we initially thought . Most of us know that it increases our risk of liver disease and heart disease. Less of us are aware that alcohol directly increases your risk of mouth cancer, throat cancer, and even breast cancer. And studies are emerging that look into the link between excessive drinking and developing dementia in older age.

If you’ve been drinking over the limit for a long time the idea of a cure-all “alcohol detox” is tempting – it’s no wonder movements like Dry January are getting popular. So can they work? That’s what a study on the Channel 4 show Live Well Longer aimed to find out. We asked liver specialist Professor Kevin Moore (who helped Channel 4 carry out the study) what we can learn from the study, and whether a “detox” from alcohol can really work.

What did the study involve?

The study looked at about 20 women who stopped drinking for a month. The study largely replicated the findings recently published by Professor Moore in the BMJ Open entitled “Short-term abstinence from alcohol and changes in cardiovascular risk factors, liver function tests and cancer-related growth factors: a prospective observational study.”

In the original BMJ study, Professor Moore took a group who gave up alcohol for a month and compared this to a group who continued their normal drinking habits. Both groups were regular drinkers, with the average participant drinking around 35 units per week. People who had liver disease or alcohol dependence were excluded.

What did it show?

The results of the BMJ study were dramatic. After giving up alcohol for just one month, participants experienced:

  • a significant drop in blood pressure and cholesterol
  • a huge drop (25%) in insulin resistance, the main factor which drives the development of diabetes and fatty liver disease
  • significant weight loss
  • a drop in two growth factors that are linked with the development of cancer

The 20 people who replicated the study for Live Well Longer experienced similar effects. They also reported that they slept better and had improved concentration.

Does this mean I can go on an alcohol “detox” for a month?

“Detoxing” is a popular concept at the moment, and it’s tempting to conclude from this that all you need is month of no drinking to “refresh” your liver and improve your health long-term.

But that is not what this study shows. All it shows is what happens in the short-term after a month of no drinking. As Professor Moore says, we need to monitor the participants long-term to see if there are any significant health improvements from a month-long break from drinking. If you return to excessive drinking levels afterwards, the initial health benefits quickly dry up. All we do know is that subjects who gave up alcohol for a month were less likely to drink as heavily as previously in the first 8 months after dry January. Until more research is carried out, we won’t know the longer term effects.

Still, the results of our studies were promising – they show how quickly your health could improve just one month into a longer period of alcohol abstinence.

By Professor Kevin Peter Moore
Hepatology (liver specialist)

Professor Kevin Moore is one of London's leading and most reputable liver specialists. He is Professor of Hepatology at University College London (UCL) and sees and treats all forms of liver disease at the Royal Free London Foundation Trust.  For twenty years, he was an integral part of the liver transplant team which lead the treatment of cirrhosis complications.

Professor Moore sees patients with a wide variety of liver problems from abnormal liver function tests to advanced cirrhosis.  He currently leads the Alcohol Care Team at the Royal Free London NHS Foundation Trust and treats patients with alcohol dependency and alcohol-related liver problems, as well as fatty liver disease, autoimmune liver disease and cirrhosis.

Professor Moore chaired the writing of the National Plan for Liver Services in 2010, has published two books in acute medicine (Oxford Handbook of Acute Medicine and the Oxford Desk Reference), and has been widely published in numerous peer-reviewed journals. 

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