People with light-colored eyes may be more likely to develop alcoholism than those with dark brown eyes, according to a study from the University of Vermont. The study was published in July 2015 in the American Journal of Medical Genetics Part B: Neuropsychiatric Genetics.
Here’s What We Know
Researchers at the University of Vermont found that people with light-colored eyes — blue, green, gray or brown in the center — may have a greater chance of becoming dependent on alcohol.
Using a sample of 1,263 European-Americans, researchers found alcohol dependence more prevalent among those with light-colored eyes, as compared to those with dark brown eyes. The study also found that blue-eyed people had the highest rates of alcohol dependence. The association remained significant even after researchers controlled for other factors such as age, gender and genetic ancestry.
The genetic research was led by Arvis Sulovari, a doctoral student in cellular, molecular and biomedical sciences, and Dawei Li, PhD, assistant professor of microbiology and molecular genetics at the University of Vermont. This is the first work to make a direct connection between alcohol dependence and eye color. Alcohol dependence was defined in the study using criteria from the Diagnostic and Statistical Manual of Mental Disorders (fourth edition).
The study outlines eye color’s genetic components and reveals that they “line up along the same chromosome as the genes related to excessive alcohol use.” Analyses showed a “statistically significant number of genetic interactions between eye-color genes and AD-associated [alcohol dependence] genes.” What researchers don’t know, however, is why.
Dr. Li wants to replicate the study with large database of patient samples. Delving deeper into the relationship and interaction of cultural background and genetic makeup will fuel his quest to “find the mechanisms of mental illness.”
All the genes identified in the past 20 years, “can only explain a small percentage of the genetics part that has been suggested. A large number is still missing, is still unknown” Dr. Li said.
Regardless of the reasons for alcohol abuse or dependence, treatment can help.
By Suzanne Kane