Binge drinking changes people’s genes – making them crave booze even more, warns a new study.
Heavy alcohol consumption alters DNA – creating a vicious cycle that makes the problem worse, according to the research.
Scientists said their findings shed light on how the lure of a pint of beer or glass of wine can become so hard to resist.
They said the study could also lead to better ways of treating alcohol addiction.
Senior author Professor Dipak Sarkar, of Rutgers University in the US, said: “We found people who drink heavily may be changing their DNA in a way that makes them crave alcohol even more.
“This may help explain why alcoholism is such a powerful addiction, and may one day contribute to new ways to treat alcoholism or help prevent at-risk people from becoming addicted.”
In 2016 more than three million people died around the globe from the harmful use of alcohol, according to the World Health Organisation.
That equates to an alarming one in 20 of all global deaths. More than three-quarters of cases were among men.
In addition, alcohol abuse was behind more than five percent of the worldwide toll of disease and injuries.
The study, published in the journal Alcoholism: Clinical & Experimental Research, focused on two genes implicated in the control of drinking behaviour.
One known as PER2 influences the body’s biological clock while the other, called POMC, regulates our stress-response system.
By comparing blood samples from moderate, binge and heavy drinkers, Prof Sarkar and colleagues found both had changed in the latter two groups.
That was through an alcohol-influenced modification process called methylation by which genes are activated by environmental factors, such as diet and lifestyle.
The binge and heavy drinkers also showed reductions in gene expression – the rate at which they create proteins. These increased with greater alcohol intake.
What is more, these alcohol-fuelled changes in the genes of binge and heavy drinkers were associated with a greater desire for alcohol.
This was illustrated by a three day experiment in which the participants viewed stress-related, neutral or alcohol-related images.
They were also shown two containers of beer and subsequently tasted it, with their motivation to drink evaluated.
Prof Sarkar, an environmental and biological scientist, said: “We found increased methylation of the PER2 and POMC DNA – reduced expression of these genes in the blood samples of the binge and heavy drinkers – relative to the moderate, non binge drinkers.
“Increased PER2 and POMC DNA methylation was also significantly predictive of both increased levels of subjective alcohol craving immediately following imagery, and with presentation of the alcohol prior to the alcohol taste test, as well as with the amount consumed during it.”
He added: “These data establish significant association between binge or heavy levels of alcohol drinking and elevated levels of methylation and reduced levels of expression of POMC and PER2 genes.
“Furthermore, elevated methylation of POMC and PER2 genes is associated with greater subjective and behavioural motivation for alcohol.
Prof Sarkar said the findings may eventually help researchers identify biomarkers – measurable indicators such as proteins or modified genes – that could predict an individual’s risk for binge or heavy drinking.
By Mark Waghorn