S u m m a r y :
Alcohol consumption increases the risk of cancer by damaging DNA—how this happens is explained in a new study published in the journal Nature.
Alcohol consumption has been associated with increased cancer risk in previous researches. How does this happen though? What links the two? A new study, conducted by scientists from the MRC Laboratory of Molecular Biology, Cambridge, explains how drinking brings about a greater vulnerability to cancer—through DNA damage.
The team, led by Ketan Patel, exposed mice to alcohol with the aim of showing how it leads to permanent genetic damage. The mice were fed diluted alcohol, ethanol. The researchers, then, performed chromosome analysis and DNA sequencing to analyse the damage done to the DNA of the mice that would have resulted from the harmful chemical produced in the body upon drinking alcohol, namely acetaldehyde.
The findings show that acetaldehyde breaks and damages DNA in the blood stem cells. Consequently, chromosomes are rearranged, thereby permanently modifying the DNA sequences in these cells. Such damage to DNA causes healthy stem cells to become faulty such that diseases like cancer can follow.
“Some cancers develop due to DNA damage in stem cells. While some damage occurs by chance, our findings suggest that drinking alcohol can increase the risk of this damage,” says Patel.
Another interesting finding showcases the inability of the body to defend itself. Normally, the body will shield itself from alcohol damage through a family of enzymes called aldehyde dehydrogenases (ALDH), molecules that are meant to break down acetaldehyde into acetate; the latter is actually useful in generating energy. However, millions of people do not benefit from this because they either do not have the enzyme or they have faulty versions thereof; this applies to many from South East Asia. These people are, thus, specially vulnerable to the negative effects of alcohol, as shown by the new study: mice lacking the ALDH enzyme suffered from four times more DNA damage when taking in alcohol than mice with the proper enzyme.
Another defence system is found in DNA repair mechanisms. However, these do not always work.
“Our study highlights that not being able to process alcohol effectively can lead to an even higher risk of alcohol-related DNA damage and therefore certain cancers. But it’s important to remember that alcohol clearance and DNA repair systems are not perfect and alcohol can still cause cancer in different ways, even in people whose defence mechanisms are intact,” says Patel.
So, you might want to reconsider your drinking habits.
“This thought-provoking research highlights the damage alcohol can do to our cells, costing some people more than just a hangover,” says Cancer Research UK cancer expert, Linda Bauld.
“We know that alcohol contributes to over 12,000 cancer cases in the UK each year, so it’s a good idea to think about cutting down on the amount you drink.”