A new study has confirmed what many experts already suspect—that alcoholism has a strong genetic component. However, the specific findings are surprising. According to the study, people who have light-coloured eyes are at a higher risk for alcohol dependency than those with darker-coloured eyes.
The study was published in the July issue of the American Journal of Genetics: Neuropsychiatric Genetics. In the course of the study, more than 1,200 white Americans with alcohol dependency problems were analysed. It found that alcohol dependency increased as the subject’s eye colour lightened.
Those individuals involved in the study who had blue eyes suffered from the highest incidences of alcohol dependency. While the authors of the study are not sure why the connection exists, they are now convinced that there is a link between lightness of eye colour and a proclivity for alcohol dependency.
There is further evidence to back up this assumption. Specifically, the data collected during the study suggested that the same genetic components that determine eye colour tend to line up along the same chromosome as those genes that correlate to excessive alcohol use.
This is line with prevailing gene theory, which states that the alleles of a single gene can interact in several different ways and at various functional levels. In other words, there is no more a gene for light-coloured eyes than there is one for alcoholism. Instead, alleles work together to produce overlapping—but in many cases, predictable—results. This allows scientists to track correlations amongst genetic indicators.
This study introduces intriguing possibilities for healthcare providers and addiction therapists. It suggests that eye colour could ultimately be useful in clinics and alcohol rehab facilities for dependence diagnosis.
At this point, the link between eye colour and alcohol dependency is not confirmed, but the team plans to continue their research.