Weekly exceeding 17 units of alcohol – roughly five large glasses of wine or five beers – damages the DNA and hastening ageing, found a University of Oxford study.
It damages the telomeres, the caps on the end of the chromosomes. Damage to these areas has previously been linked to Alzheimer’s and cardiovascular disease. People with healthier, longer telomeres are also thought to have longer lifespans.
The top 40% of drinkers – who consumed more than 17 units a week – were found to have some telomere shrinkage caused by alcohol consumption. However, the remaining 60%, who drink less than 17 units a week, were found to be genetically undamaged.
Someone who drinks 32 units per week, or about 10 large glasses of 13% alcohol by by volume (ABV) wine, is biologically three years older than someone on 10 units a week, roughly three large glasses of wine, for example.
But the research found no link between alcohol consumption and biological ageing below the 17-unit threshold, with someone having one whisky a week as unaffected as someone who has a glass of wine every week night.
For their study, they looked at data from almost half a million people enrolled in the UK Biobank. The team looked for tell-tale genetic markers showing how much alcohol a person drinks. Their telomere length was measured in a laboratory after taking DNA from a swab.
‘Necessary minimum amount’
“This finding suggests that a necessary minimum amount of alcohol consumption is required to damage telomeres,” the researchers write in their study, published in Molecular Psychiatry. “Similar relationships with alcohol have been described for other health outcomes,” they add.
Exactly how alcohol intake is linked to telomere damage remains unknown and this study does not provide causal evidence but does show a strong observational connection.
One potential harmful mechanism suggested is that the breakdown of alcohol molecules leads to oxidative stress and inflammation, which are hazardous to DNA.
“These findings support the suggestion that alcohol, particularly at excessive levels, directly affects telomere length,” said study lead Dr Anya Topiwala from Oxford Population Health.
“Shortened telomeres have been proposed as risk factors that may cause a number of severe age-related diseases, such as Alzheimer’s disease.
“Our results provide another piece of information for clinicians and patients seeking to reduce the harmful effects of excess alcohol. Furthermore, the dose of alcohol is important – even reducing drinking could have benefits.”
‘Clear links with ageing’
Dr Richard Piper, chief executive of Alcohol Change UK, welcomed the results.
He said: “This particular study shows clear links between consuming alcohol and ageing, and points towards a possible link between alcohol and Alzheimer’s.
“The researchers are transparent that this study does not prove a causal link, but they also make a well-argued case about the likely biological mechanism.
“In general, there is an ever-larger body of science showing how, exactly, alcohol causes so much ill-health and so many early deaths.”
Study details
Alcohol consumption and telomere length: Mendelian randomisation clarifies alcohol’s effects
A. Topiwala, B. Taschler, K. P. Ebmeier, S. Smith, H. Zhou, D. F. Levey, V. Codd, N. J. Samani, J. Gelernter, T. E. Nichols & S. Burgess
Published in Molecular Psychiatry on 26 July 2022
Abstract
Alcohol’s impact on telomere length, a proposed marker of biological aging, is unclear. We performed the largest observational study to date (in n = 245,354 UK Biobank participants) and compared findings with Mendelian randomisation (MR) estimates. Two-sample MR used data from 472,174 participants in a recent genome-wide association study (GWAS) of telomere length. Genetic variants were selected on the basis of associations with alcohol consumption (n = 941,280) and alcohol use disorder (AUD) (n = 57,564 cases). Non-linear MR employed UK Biobank individual data. MR analyses suggested a causal relationship between alcohol traits, more strongly for AUD, and telomere length. Higher genetically-predicted AUD (inverse variance-weighted (IVW) β = −0.06, 95% confidence interval (CI): −0.10 to −0.02, p = 0.001) was associated with shorter telomere length. There was a weaker association with genetically-predicted alcoholic drinks weekly (IVW β = −0.07, CI: −0.14 to −0.01, p = 0.03). Results were consistent across methods and independent from smoking. Non-linear analyses indicated a potential threshold relationship between alcohol and telomere length. Our findings indicate that alcohol consumption may shorten telomere length. There are implications for age-related diseases.
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