Taking more than 10 beers a week shortens your lifespan
A mug of beer.
What you need to know:
- Researchers add that regular alcohol consumption can increase oxidative stress (caused by a build-up of damaging free radicals in cells) and inflammation, which leads to shortened telomeres.
Scientists have linked consuming 17 or more units of alcohol a week with shortened telomeres, the regions of repetitive DNA sequence that cap chromosomes more like a plastic tip on a shoelace.
Telomeres function by preventing chromosomes from losing base pair sequences at their ends apart from stopping chromosomes from fusing to each other.
However, each time a cell divides, some of the telomere is lost (usually 25-200 base pairs per division).
According to Anya Topiwala, a researcher from the University of Oxford, telomere length decreases as we age in normal ageing, but the concern is that shorter telomeres have been linked with lots of diseases of later life like heart disease, cancer and Alzheimer’s.
This is why to better understand alcohol’s effect on telomere length, Topiwala and her colleagues analysed 245,354 participants aged between 40 to 69 from the UK Biobank study, which holds medical and genetic information on half a million people.
Telomere length was calculated from a single blood sample taken from each participant. The team compared this with the participants’ self-reported weekly alcohol consumption.
Though this type of comparison can’t tell the researchers whether alcohol alone is at least partly responsible for shorter telomeres, as other lifestyle factors like diet may also influence telomere length, their findings showed that the participants who had been diagnosed with alcohol-use disorder were more likely to have shorter telomeres.
The researchers repeated the experiment, this time using data from an earlier genome-wide association study to better understand the role of alcohol specifically and found that 93 genetic variants were associated with increased alcohol use.
“It’s sort of like a randomised control trial,” Topiwala explained.
“Like when you randomise people to have a drug or not have a drug, but obviously you can’t do that with alcohol.”
The method, called mendelian randomisation, groups people by the genetic variants they possess that have been linked to particular behaviours.
The idea is that these genes were randomly allocated at conception and are therefore not affected by lifestyle factors.
The team devised a genetic risk score based on these variants and found that the participants with a higher genetic risk score for increased alcohol consumption were more likely to have shorter telomeres.
In both the Biobank and GWAS experiments, the team found that the participants who had been diagnosed with alcohol use disorder had the shortest telomeres though experts point out that shorter telomeres were also seen in those who were genetically more likely to consume between 17 and 28 units a week.
They add that regular alcohol consumption can increase oxidative stress (caused by a build-up of damaging free radicals in cells) and inflammation, which leads to shortened telomeres, according to Ms Topiwala.
