Michael Mosley

Michael Mosley is a science writer and broadcaster, who presents Trust Me, I’m A Doctor on BBC Two. His latest book is The Clever Guts Diet (£8.99, Short Books).

Is it worth giving up booze for a month?

“DOES GIVING UP ALCOHOL FOR JUST A FEW WEEKS MAKE MUCH IMPACT?”

Last month, some people stayed off the booze to Go Sober For October. And after the excesses of the festive period, which is just around the corner, comes the perennial question: should I join in Dry January? There are excellent reasons to drink less if you are currently over the guidelines, which in the UK are 14 units of alcohol a week for men and women. That translates into roughly six glasses of wine, or six pints of beer. A week.

The dangers of going well above these guidelines include increased risk of cancer, obesity and heart disease. Plus, of course, things like crashing your car. As the facts about alcohol become widely available, more and more people are giving it up, permanently. A recent study found that a third of under-25s don’t drink at all.

I can see the advantages of total abstinence, but does giving up alcohol for just a few weeks make much of an impact? This time last year I gave it a go for BBC Focus, and was generally unimpressed with the results. Over the course of a rather dull month I lost a bit of weight, saved some money, and then took up drinking again as soon as it was over. But how do others react, particularly heavier drinkers than me? A team of scientists led by Prof Rajiv Jalan asked a group of 94 healthy, middleaged people, who averaged 25 units a week, to give up drinking for a month. At the end of the trial, the volunteers’ body weight was down by an average of 1.5 per cent, and their blood pressure reduced by an average of 6 per cent. The most impressive drop was in their vascular endothelial growth factor (VEGF), which is a marker of cancer risk. It went down by a whopping 42 per cent.

At Trust Me, I’m A Doctor, we wanted to find out whether modest drinkers would get the same benefits from a dry month as the heavier drinkers, and whether they would continue to cut back once the abstinence month was over. We recruited 26 volunteers, some who usually drank within the guidelines, others who were way over.

Before and after their dry month we gave them a health check. We measured liver fat, blood pressure, liver disease biomarkers and VEGF levels, among other things. As we also wanted to find out if giving up alcohol for a month affected their alcohol intake once they were free to return to drinking, we invited them to come back to be tested a final time, three weeks after their dry month was over.

All our volunteers stuck to their booze-free month and all saw health improvements – even those who normally drank less than the government recommended levels. Their VEGF levels, liver fat and weight all fell, while their quality of sleep, concentration and liver health improved. The effect was, not surprisingly, more pronounced in the volunteers who drank more than the government recommended guidelines of 14 units.

The lightest drinkers, having been off for a month, soon returned to drinking at their old levels. What was encouraging was that the heavier drinkers, who normally drank more than 14 units a week, did not. Three weeks after their dry month was over they were drinking, on average, 70 per cent less than they were before.

Yes, it was a small study that was done for a short period of time, but it certainly suggests that the heavy drinkers among you might think of taking a Dry January pledge. I may even join you this year.