Moreover, among the light-eyed, subjects with blue eyes had the highest rate of alcohol dependency. An alcohol use disorder (AUD) is a medical condition characterized by an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences. It encompasses a range of behaviors from mild to severe and can develop into a significant health risk if left untreated. Some examples of AUDs include binge drinking, chronic heavy drinking, and alcoholism. According to the 2022 National Survey on Drug Use and Health (NSDUH), 28.8 million adults had AUD in the last year.
Once the team recognized an eye color connection, they reanalyzed their data three times, comparing the participants’ age, gender and differences in backgrounds and locations. According to some researchers, melanin, which is present in higher amounts in the irises of darker eyes, might reduce alcohol tolerance (and chances of dependence). When it comes to what causes AUD, the genetics behind it are even more complex than those of eye color. In general, scientists agree that there are genetic and environmental factors at play, with many variables that make pinpointing an exact “cause” nearly impossible.
Eye Color Linked to Alcoholism Risk
- People with blue eyes had the highest rates of alcohol dependence, according to the study.
- “What has fascinated me the most about this work has been investigating the interface between statistics, informatics and biology,” says Sulovari.
- For that reason, persons who are most sensitive to alcohol would, perhaps, be less likely to drink enough to become physiologically addicted.
- But if you’re concerned about the genes behind alcoholism, for now you might do better to consider your own family history of alcoholism than your eye color.
- Using the database, the researchers identified over 1,200 people with European ancestry who suffered from alcohol dependence.
Experts also point out that the genetic determinants of eye color are complex and not fully understood, and any genetic overlap with alcoholism-related genes is yet to be substantiated. Genetic counselors and researchers alike agree that while intriguing, the evidence is far from conclusive and warrants more extensive research. They advocate for a nuanced understanding of the genetic and environmental factors contributing to alcoholism rather than attributing risk to physical characteristics like eye color. A pivotal study from the University of Vermont, which suggested that individuals with light-colored eyes, particularly blue, showed higher rates of alcohol dependency than those with darker eyes, is a frequent subject of this critique. Experts stress that while the study presents a correlation, it does not establish a causal relationship between eye color and alcoholism.
Genetic research is fraught with complexities that challenge the validity of studies exploring connections like those between eye color and alcoholism. One such challenge is participation bias, a significant obstacle that skews results based on whats an enabler who chooses to participate in genetic studies. A recent development in statistics promises to mitigate this issue, providing researchers with tools to better manage and understand biases inherent in genetic research. ScienceDaily reports a breakthrough that could enhance the accuracy of genetic studies.
With so many people affected by AUD, recognizing the signs of this disease is crucial for early intervention and successful management. For example, if a specific genetic overlap between blue eyes and alcoholism were confirmed, individuals with this trait could benefit from targeted education and prevention programs. Strategies could also involve modifications to treatment approaches to accommodate genetic vulnerabilities, similar to mental health services adjusting their support structures to prevent further harm or trauma. Studies found a statistically significant association between blue eye color and alcohol dependency among Americans of European ancestry. Here, I discuss the basis for light eye color and the evidence for a genetic contribution to risk for alcohol dependency.
Alcohol Use Disorder: Definitions, Causes, and Prevalence
Results showed that among males and females, irrespective of age, participants with blue eyes had a higher BAC than the others … This ecological result suggests that iris pigmentation represents a biological marker for underlying factors involved in higher alcohol consumption. Previous research on people of European ancestry has shown that those with light-colored eyes may consume more alcohol on average than dark-eyed individuals, the researchers said. Other studies also have demonstrated a link between eye color and people’s risk of psychiatric illness, addiction and behavioral problems, according to the study. People with blue eyes may be more likely to become alcoholics than dark-eyed individuals, a new study suggests.
It’s posited that the genetic determinants for eye color may reside on the same chromosome as those affecting alcohol use behavior, as suggested by the research highlighted on DrugFree.org. While this information opens new avenues for understanding genetic predispositions to alcoholism, the scientific community emphasizes the necessity for additional research to unravel the complexities of this potential connection. The genetics of eye color are far more complex than previously thought, with recent research revealing the involvement of multiple genes. Eye color is determined by the combination of genes inherited from both parents, and blue eyes result from specific genetic interactions. While eye color was once believed to be determined by a single gene, modern genetic studies have identified over 50 genes contributing to this trait.
The supposed connection between blue eyes and AUD (and, more specifically, the link to higher alcohol tolerance). About 6,000–10,000 years ago, probably in the area of the Black Sea, a single individual was born with a mutation that programs reduced OCA2 gene expression and blue eyes.1 The evidence suggests that all people with blue eyes carry this same variant. So the parts of the world where descendants of that founder individual are most common have the highest frequency of blue eyes; where those descendants are rare, darker eye colors are the dominant eye color. In this field study carried out in a French barroom, we hypothesized that the average blood alcohol concentration of participants with blue eyes would be higher than people with other eye color. We measured blood alcohol concentration with a breathanalyzer among 61 customers from various occupational backgrounds, and calculated the association between eye color and BAC.
More in Mental Health
“This suggests an intriguing possibility – that eye color can be useful in the clinic for alcohol dependence diagnosis,” Sulovari says. People with blue eyes might have a greater chance of becoming alcoholics, according to a unique new study by genetic researchers at the University of Vermont. This is tricky, because scientists still don’t know much about the mechanisms that cause alcoholism. The genes we’ve identified over the past two decades “can only explain a small percentage of the genetics part that has been suggested,” he added, “a large number is still missing, is still unknown.”
As it turns out, the genes that determine eye color are located on the same chromosome as those that control alcohol dependence. And as scientists found in this most recent study, there is a “statistically significant” interaction (defined as an affect of one gene on the behavior of another) between the eye color and alcoholism genes. In the study, researchers looked at 1,263 Americans of European ancestry, including 992 people who were diagnosed with alcohol dependence and 271 people who were not diagnosed with alcohol dependence.
Neither Sulovari or lead author Dawei Li, professor of microbiology and molecular genetics at the University of Vermont, said they think there will be one genetic silver bullet to stop alcoholism. But knowing more about the genetics involved could mean that someday doctors might be able to identify from specific genes which people are most at risk for certain disorders, including alcoholism, by looking at their eye color or hair color. The study, published this week, examined genetic samples from 1,263 people with alcohol dependency and found that those with lighter eyes, especially blue eyes, appeared to develop alcoholism at a higher rate.
