Why can some people have a glass of wine or beer with their meal without feeling compelled to drink more, whereas others can’t seem to stop drinking? Can some people “hold” their liquor better than others? Does alcoholism tend to run in families? Does genetics hold the key to developing medications to treat alcoholism and its effects on the body? Researchers have been trying to find answers to questions such as these for several decades, seeking to identify the factors that influence a person’s risk of becoming alcohol dependent. Research, to date, indicates that both your genetic makeup (i.e., the information stored in the DNA that you inherited from your parents) and your environment (i.e., how you live) influence your risk for alcohol abuse and alcoholism.1 Your genes certainly play an important role, influencing how your body responds to alcohol, how sensitive you are to its effects, and how likely you are to have a problem with alcohol. However, environmental factors—such as being surrounded by people who are heavy drinkers and who encourage you to drink—also can raise your risk for drinking too much.
The next question then becomes just how much of this risk is determined by our genes—that is, how much can be attributed to factors beyond our control. By studying large families with alcoholic and nonalcoholic members, comparing identical and fraternal twins, and studying adopted children and their biological and adoptive families, researchers found that about half of our risk for alcoholism is influenced by genetics.2,3 The remaining risk is related to the influence of environment—where and how we live. The two factors also work together in complex ways.
Understanding how genetics influences alcoholism also is important for another reason. Knowing the genes involved in this disease could help researchers and clinicians identify those who are most at risk of becoming alcoholic and understand how alcohol affects the body. These individuals then could be targeted more effectively for prevention and treatment efforts.1
This Alcohol Alert describes how research is helping to identify the genes involved in alcoholism. In examining this research, one thing becomes clear: Unlike for some other diseases, there is no single gene that determines whether you will develop a problem with alcohol; instead, many genes influence your risk for developing alcoholism, each of which only has a small impact. Further, environmental influences may override or blunt the effects of the genes that increase risk. This overview describes how researchers are trying to tease apart which of the thousands of genes and millions of gene variants that make up your DNA play a role in alcoholism, how some of these genes act, and how these genes interact with your environment to determine how you and your body respond to alcohol.
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