May 03, 2015

Eye color and alcohol dependence

American Journal of Medical Genetics Part B: Neuropsychiatric Genetics DOI: 10.1002/ajmg.b.32316

Eye color: A potential indicator of alcohol dependence risk in European Americans

Arvis Sulovari et al.

In archival samples of European-ancestry subjects, light-eyed individuals have been found to consume more alcohol than dark-eyed individuals. No published population-based studies have directly tested the association between alcohol dependence (AD) and eye color. We hypothesized that light-eyed individuals have a higher prevalence of AD than dark-eyed individuals. A mixture model was used to select a homogeneous sample of 1,263 European-Americans and control for population stratification. After quality control, we conducted an association study using logistic regression, adjusting for confounders (age, sex, and genetic ancestry). We found evidence of association between AD and blue eye color (P = 0.0005 and odds ratio = 1.83 (1.31–2.57)), supporting light eye color as a risk factor relative to brown eye color. Network-based analyses revealed a statistically significant (P = 0.02) number of genetic interactions between eye color genes and AD-associated genes. We found evidence of linkage disequilibrium between an AD-associated GABA receptor gene cluster, GABRB3/GABRG3, and eye color genes, OCA2/HERC2, as well as between AD-associated GRM5 and pigmentation-associated TYR. Our population-phenotype, network, and linkage disequilibrium analyses support association between blue eye color and AD. Although we controlled for stratification we cannot exclude underlying occult stratification as a contributor to this observation. Although replication is needed, our findings suggest that eye pigmentation information may be useful in research on AD. Further characterization of this association may unravel new AD etiological factors. © 2015 Wiley Periodicals, Inc.



trevor_r said...

This is quite interesting, I wonder if such associations could be applied with other diseases too?

Frank said...

Alcohol dependency is not a disease. Maybe these people like to drink more. I'm from south europe, have blue eyes and know others as well but alcohol consumption here does not even approach the levels I saw in Sweden. I'd drink with swedish friends and some people would get going until they were knocked out and dead on the table.

Reminds me something a Belarussian once told me: if the cold catches you without some vodka in you, you wish for death.

Also remember that the ancient greeks viewed the blond (and presumably blue eyed) Scythians as very savage due to their custom of drinking a lot of wine and unwatered wine at that too. Even Tacitus wrote that "their entire race is unsatiable in wine". I suppose that it may be hard to escape the lure of beer with the cold outside and 4000 years of adaptation to one form of Jagermeister or another.

Gary said...

Unfortunately, MDs who attempt to "do science" are the worst for the "correlation implies causality" fallacy.