Alcohol abuse is a worldwide problem affecting more than 75 million people each year, with more than three million people dying from the harms of alcohol abuse.
Scientists are beginning to explore genetic and environmental factors that can increase a person’s risk of developing an alcohol abuse disorder.
Researchers are zeroing in on two genes of interest in the control of drinking behaviour. One is called PER2 which influences the body’s biological clock and the other is POMC which has a role in the stress-response system.
Excessive alcohol consumption is known to change the circadian rhythm of laboratory animals and humans along with changes in stress hormones cortisol so these are key genes to study.
Looking at the PER2 and POMC genes of 47 moderate, binge and heavy drinkers, the researchers found that these genes had changed in their degree of methylation in the binge and heavy drinkers.
DNA methylation is called an epigenetic effect, which while not changing the structure of the gene, does affect its function.
Alcohol was considered the likely culprit to explain these epigenetic effects. The gene methylation changes resulted in less functional protein being made from the genes.
In a second phase of the study, the volunteer drinkers looked at images designed to cause stress, alcohol-related images or emotionally neutral images. The volunteers were also asked to look at filled beer mugs and to taste the beer as well.
Their desire to drink at each stage of the experiment was measured and suggested that the epigenetic changes in the binge and heavy drinkers were associated with a greater motivation to drink alcohol.
This research helps to explain why alcohol can create such a powerful addiction at the genetic level. The findings from this current research may help identify genetic biomarkers that could predict a person’s future risk for alcohol abuse.