The damage is mainly caused by acetaldehyde, a chemical produced during alcohol treatment by the body.
Anyone taking part in "dry January" may have an extra incentive to stay booze-free as United Kingdom scientists say they have discovered how alcohol can cause irreparable damage to DNA in stem cells, increasing the risk of cancer.
A team at the Medical Research Council Laboratory of Molecular Biology, Cambridge, gave diluted alcohol - chemically known as ethanol - to mice.
Drinking alcohol doesn't just damage the liver and kidneys - turns out it could increase cancer risks and damage DNA as well.
Alcohol causes an increased risk of getting mouth, throat, oesophageal, larynx, breast, liver and bowel cancer, even in light drinkers. As well as explaining why some people feel inordinately unwell after drinking alcohol, this build-up of acetaldehyde can result in greater DNA damage.
Much previous research looking at the precise ways in which alcohol causes cancer has been done in cell cultures.
Alcohol causes cancer by scrambling DNA in our cells, new research has found. It can be even more deadly than most of the people thought and damage DNA mechanism.
Researchers highlighted the importance of understanding the DNA blueprint within stem cells citing one simple reason: when healthy stem cells are corrupted, they can give rise to cancer.
Humans counter the ill effects of acetaldehyde by secreting an enzyme called acetaldehyde dehydrogenases (ALDH) that helps in the breakdown process. "While some damage occurs by chance, our findings suggest that drinking alcohol can increase the risk of this damage", Professor Ketan Patel, the lead author of the study and scientist at the MRC Laboratory of Molecular Biology, said in a press-release. These enzymes break down harmful acetaldehyde into acetate, which our cells can use as a source of energy. Although most of the time they reverse different types of DNA damage, some people carry mutations so their cells aren't capable of carrying out any such 'repair work'.
The study said that over 540 million people in Asia carry a mutation in the ALDH2 gene, which means they can't process acetaldehyde which causes the widely documented red flush reaction in Asians.
In the study, when mice lacking a critical ALDH enzyme were given alcohol, their DNA suffered four times as damage compared with mice with a properly functioning version of the enzyme.
"24,000 cases of cancer a year could be prevented in the United Kingdom if nobody drank alcohol".
It has been estimated nearly six per cent of all cancer deaths worldwide could be attributed to alcohol.
"I$3 t's important to remember that alcohol clearance and DNA fix systems are not flawless and alcohol can still cause cancer in different ways, even in people whose defence mechanisms are intact".