Huge genetic study suggests alcohol accelerates biological aging
A comprehensive new Oxford study has added to the growing body of research highlighting the health effects of alcohol. The large-scale genetic analysis suggests that alcohol consumption directly accelerates aging, by shortening telomeres.
Alcohol is among the most widely used recreational drugs, so it’s extremely important to examine its health impacts. Unfortunately, various studies have revealed that alcohol permanently damages DNA, directly causes cancer, contributes to cognitive decline and early-onset dementia, and can shrink the brain to the equivalent of 10 years of aging. And now a new study has found more evidence that alcohol consumption can accelerate biological aging.
Telomeres are repetitive sequences of DNA that form protective caps on the tips of chromosomes. Every time a cell divides, a section of these “junk” sequences is lost, and eventually telomeres wear away enough that useful DNA starts to be affected. This causes the cell to stop dividing, and contributes to many of the biological signs of aging. As such, telomere length is often used as a biomarker for aging.
In the new study, researchers from Oxford Population Health examined the association between alcohol intake and telomere length, using data from over 245,000 people taking part in the UK Biobank project. To investigate any potential causation, the team used a genetic technique known as Mendelian Randomization (MR), which looks at variations in certain genes – in this case, some that had previously been linked to alcohol consumption and alcohol use disorders.
In the MR analysis, the team found a clear link between high alcohol intake and shorter telomeres – drinking 32 units of alcohol (about 11 glasses of wine) per week showed telomere shortening equivalent to around three years of aging, compared to those who drank 10 units. People genetically predicted to have alcohol use disorder were also found to have about three years’ worth of aging damage to their telomeres.
The team backed up this MR analysis with observational studies of participants’ reported weekly drinking habits. This showed similar results – people who drank more than 29 alcohol units (roughly 10 large glasses of wine) per week showed telomere shortening equivalent to between one and two years of aging, compared to people who drank less than six units of alcohol (about two glasses of wine) per week.
The association seemed to only be significant for people drinking more than 17 units per week, suggesting that it takes at least a moderate level of alcohol consumption before the telomere damage kicks in.
Although the results aren’t conclusive, the team says that the evidence is strong. For one thing, the effects were only found in current drinkers, but not in participants who had never drank or had stopped drinking. The MR analysis also highlighted one particular gene as the most influential – AD1HB, which plays a role in metabolizing alcohol.
“These findings support the suggestion that alcohol, particularly at excessive levels, directly affects telomere length,” said Dr. Anya Topiwala, lead author of the study. “Shortened telomeres have been proposed as risk factors which 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.”
The research was published in the journal Molecular Psychiatry.
Source: Oxford University