January tends to be a month filled with big self-improvement goals as many people set New Year's resolutions.

One common resolution is cutting back on alcohol.

New research out this week showing how alcohol damages cellular DNA gives new insights into how dangerous drinking alcohol can be and suggests that this resolution may actually be a lifesaver.

Our bodies break the alcohol that we drink down into a chemical called acetaldehyde. Previous studies have found that acetaldehyde is toxic when applied in large doses to cells in a lab. In this new research, scientists looked at the effects of acetaldehyde on the DNA of blood stem cells in living mice. Stem cells in our blood are responsible for creating the red and white blood cells which carry oxygen through the body and help to fight infections.


When we drink alcohol, our bodies have two protective mechanisms that kick in to protect us from the acetaldehyde toxin, the first mechanism clears away the acetaldehyde using a protective enzyme called aldehyde dehydrogenase 2 and the second mechanism repairs the DNA damage.

About five million people worldwide are unable to produce the protective enzyme aldehyde dehydrogenase in what is colloquially referred to as 'Asian flush syndrome' due to it commonly affecting people of East Asian descent. Sufferers of this syndrome typically suffer from red flushed cheeks when they drink alcohol caused by the build-up of acetaldehyde causing the blood vessels to dilate and the face to turn red.

The lack of DNA repair mechanism is often associated with women who carry the BRCA 1 or BRCA 2 gene mutations which predispose them to breast cancer.

To understand the protective nature of these two mechanisms, some of the mice in the study were genetically modified to remove one or both of these protective mechanisms.

All the mice were then given diluted doses of alcohol over 10 days while the stem cells in their blood were analysed to see the effects of the alcohol.

The researchers found that the mice lacking the enzyme experienced four times more damage to their blood DNA than those with the enzyme. This implies that people who show cheek flushing after drinking alcohol could be at a higher risk of cancer if they drink.

In the mice that had both of their protective mechanisms removed, the acetaldehyde was found to slice through their cellular DNA causing permanent damage to the cells. After 10 days the blood in these mice was completely destroyed and gene sequencing found that the DNA in their blood stem cells had been scrambled to the point that the cells no longer functioned.

These results published in the journal Nature support other studies, including a New Zealand study published in the journal Addiction, which found a strong link between alcohol consumption and cancers of the liver, breast, bowel, upper throat, mouth, oesophagus and larynx.

As the first study to show molecular evidence using live animals that alcohol directly damages the DNA of stem cells in the blood this research provides a big breakthrough in our understanding of the effects of alcohol on our health.

In addition to reducing the risk of cancer, giving up alcohol for a month has many other benefits including better sleep and more energy through the day.

If a month off alcohol sounds appealing to you, research from the dry January challenge in the UK found that those participants who succeeded in one alcohol-free month went on to drink less alcohol in the following six months, helping them to keep their New Year's resolutions long term.