Researchers at the University of Vermont have discovered a link between eye color and alcohol dependency in Americans of European descent.
Blue eye color is the most likely risk factor for alcohol dependency among European descendants.
Source: Wikimedia Commons
Northern Europeans might have evolved light eye traits as an adaption to darker environments because lighter eyes provide a greater sensitivity to light (1). But an increased sensitivity to light may also increase individuals’ risk for seasonal affective disorder, which can result in alcohol dependency (1).
Light-eyed individuals have been found to drink more alcohol than dark-eyed people in samples of European-ancestry males and females (1). However, in spite of indirect or irregular evidence supporting the connection between eye color and the consumption of alcohol, no previous study has directly tested for a biological connection between the two (2). This study hypothesized that light-eyed people have a higher widespread incidence of alcohol dependency than dark-eyed individuals of European American descent.
The researchers at the University of Vermont used 1263 from European Americans collected by alcohol and drug dependent studies in the U.S. (1). They ran multiple genetic tests to search for protein-protein interactions between the genes that code for eye color and alcohol dependency (1).
The researchers found interactions between genes for pigment and alcohol dependency, which might reflect complicated biological interactions, such as protein-protein interactions (1). They also discovered a significant phenotypic connection between alcohol dependency and light eye colors (1). Their results suggest that blue eye color, compared to grey, green, and brown eye color, is the most likely risk factor for alcohol dependency among people of European descent (1).
This research, spearheaded by Arvis Sulovari (a graduate of the Dartmouth Class of 2010), is critical because it is the first to make a direct connection between a person’s eye color and alcohol dependence (2). The findings imply that eye pigments could be useful in future research of alcohol dependency and other alcohol consumption behaviors. Further research may reveal a linkage between other ethnic groups’ ocular features and their different levels of susceptibility to alcoholic issues.
References:
- Sulovari, A., Kranzler, H., Farrer, L., Gelernter, J., & Li, D. (2015). Eye color: A potential indicator of alcohol dependence risk in European Americans. J. Med. Genet., 168(5), 347-353. doi:10.1002/ajmg.b.32316
- University of Vermont. (2015, June 30). Eye color may be linked to alcohol dependenve. Retrieved July 5, 2015 from http://www.sciencedaily.com/releases/2015/06/150630135258.htm