New research presented at the American Society of Human Genetics’ annual meeting this month shows exactly how excessive alcohol consumption can cause changes to our DNA that may result in premature ageing. The discovery, made at the University of Iowa by Robert A. Philibert and his team, used a technique called DNA methylation to examine how regularly smoking and drinking alcohol can affect gene expression.
DNA methylation involves modifying DNA by the addition of a methyl group to the DNA chain in order to fix genes in an ‘off’ position, preventing their expression – these added groups are then copied onto new strands of DNA during replication. It has been used in previous studies that show how levels of this modified DNA change as people typically age. Consequently, it has also been used to explore how the levels are affected by cigarette smoke and alcohol at specific points along the human genome.
The new study used data obtained from the Gene Expression Omnibus to calculate biological age by measuring a person’s methylation levels along their genome. This figure was then compared to the participant’s actual age and viewed alongside data about their exposure to cigarette smoke and alcohol, allowing the link between premature ageing and these environmental factors to be analysed.
The research shows that premature ageing is closely linked with exposure to cigarette smoke, as well as both extremely low and high alcohol intake, meaning that regular but not excessive drinking was least associated with premature ageing.
However, this isn’t the first piece of published research that suggests moderate alcohol consumption may be beneficial to our health; information published by the Harvard School of Public Health lists a number of studies that have previously shown the correlation between having one or two drinks a day and a lower risk of cardiovascular diseases such as heart attacks and strokes.
The team now plan to continue their research in order to establish how methylation levels change over a person’s life span and if they are affected should the person chooses to quit smoking or drinking. In the meantime, their research enables us to educate the public on how these common lifestyle choices affect our bodies, as well as provide a quantitative measure of the adverse effects of these toxins. A final benefit of the study serves to remind students that going to the pub after a long day of lectures may not be the worst idea after all!