Study co-author Dawei Li, an assistant professor of microbiology and molecular genetics, has worked with other scientists for years to build a genetic database of more than 10,000 people. All are affected by at least one mental illness, but many have multiple disorders, including depression, schizophrenia and bipolar disorder, along with alcohol or drug dependence. People with light-colored eyes may have a higher risk of alcoholism than people with dark-brown eyes, new research suggests.
More in Health
Jehannine Austin, a psychiatric disorders expert for the National Society of Genetic Counselors, said the study was intriguing but that more work needed to be done. If you or a loved one are struggling with alcohol or other drugs, call us now to speak with a Recovery Advocate. Upon first encountering a new patient, a good physician notes physical features that suggest increased risk of pathology. A patient with clubbed fingernails or toenails should be evaluated for pulmonary insufficiency. Both cars had “extensive” damage, while Steele’s eyes were “bloodshot and glassy” and she smelled of alcohol, according to the police report fetal alcohol syndrome celebrities and newly released footage.
- 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.
- People with lighter eye colors appear to be more likely to develop alcoholism, according to a new study published in the American Journal of Medical Genetics.
- The study defined “alcohol dependence” using criteria from the Diagnostic and Statistical Manual of Mental Disorders – 4th Edition, researcher Dawei Li told The Huffington Post.
ABC News
However, the complexity of genetic research, including factors such as assortative mating and shared environment effects, often challenges the validity of such findings. For instance, the heritability of alcohol use disorders, as shown in meta-analyses of twin and adoption studies, may be influenced by these factors. Despite these challenges, twin studies continue to provide valuable insights into the genetic underpinnings of alcoholism and other addiction disorders. Another dimension to consider is the genetic overlap found by researchers, which could offer insights into the underlying reasons for this association.
Blue Eyes Genetics
The two main pigments are eumelanin (brown or black) and pheomelanin (red or yellow), which together influence the perceived color of the eyes. In individuals with blue eyes, the iris lacks significant amounts of melanin, which is why they appear blue due to the way light scatters in the absence of melanin. Identifying and treating alcohol dependency is a worthy clinical and public health challenge. Alcoholics can be secretive about their addiction and frequently deny it long after it takes a toll on their families, friends and employers. Li and Sulovari found that people with light-colored eyes–or eyes that are blue, grey, or green–were most likely to become alcohol-dependent at some point in their lifetimes when compared to people with dark brown eyes.
From an evolutionary perspective, all blue-eyed individuals may share a common ancestor. A genetic mutation that occurred between 6,000 and 10,000 years ago in a single individual from Europe has been suggested as the origin of blue eyes. This mutation affected the OCA2 gene, which plays a role in melanin production, turning off the body’s ability to produce the brown pigment in the iris.
Recent studies have sparked interest in the potential connection between eye color and the risk of alcoholism. The speculation arises from observed correlations, where individuals with lighter eye colors, particularly blue eyes, may display a higher incidence of alcohol dependency compared to those with darker eyes. Research published in the American Journal of Medical Genetics outlines genetic components that determine eye color and suggests these components are aligned with genes related to excessive alcohol use. The study authors very likely uncovered an uncanny correlation, but that doesn’t provide any big help in diagnosing alcoholism or understanding the complex genetics behind it. The intersection of genetics and behavioral health, such as the study of the connection between blue eyes and alcoholism, has the potential to significantly influence treatment and prevention strategies.
Eye Color Linked to Alcoholism Risk
According to the 2021 National Survey on Drug Use and Health, approximately 28.6 million adults aged 18 and older (11.3%) suffered from AUD in the United States. 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. The mechanism behind tolerance and dependence is based on the way alcohol affects our brain — most notably the way it changes the balance of neurotransmitters in the brain. Drinking causes a brief boost in dopamine, the feel-good neurotransmitter that fuels the brain’s reward circuit. It also increases the levels of GABA (a neurological sedative) while down-regulating its counterpart, glutamate (an excitatory neurotransmitter). The root cause of alcoholism, or alcohol use disorder, is a mix of our unique biology, personal history, personality tendencies, and environment.
By considering genetic factors more closely, medical professionals could provide more targeted and effective care for those struggling with AUD. All in all, AUD is a complex condition that involves genetic and environmental factors alike. Do blue eyes have a higher alcohol tolerance correlation, and is there a connection between blue eyes, alcohol dependence, and AUD?
The Reframe app equips you with the knowledge and skills you need to not only survive drinking less, but to thrive while you navigate the journey. Our daily research-backed readings teach you the neuroscience of alcohol, and our in-app Toolkit provides the resources and activities you need to navigate each challenge. To start, let’s take a brief look at what gives rise to eye color in the first place. It comes down to our DNA — the sequence of nucleotide molecules that work as templates for building our body’s proteins.
From that extensive database, Li’s and Sulovari’s study filtered out the alcohol-dependent patients with European ancestry, a total of 1,263 samples. The inclusion of ethnically varied groups is crucial to account for structural variation and to develop more accurate predictions of phenotypes and genetic risks across populations. Nature Reviews Genetics emphasizes the need for long sequencing reads and haplotype phasing to confront this challenge. Additionally, training a diverse community of genomic research scientists is essential for the equitable advancement of the field.